An electric switch for ac or DC supply

Abstract

An electric switch (100) for controlling current flow to a load from the power source and method thereof is disclosed. The electric switch (100) comprises a first contact (S1) for isolating the switch from a power supply, a second contact (S2) for controlling a solid-state switching element, and a third moving contact (S3) for bypassing the solid-state switching element. The switch includes a solid-state switching element connected in parallel with the power source & third moving contact (S3) and a control circuit electrically connected to the second contact (S2) and the solid-state switching element. A delay mechanism is mechanically coupled to all three contacts and configured to sequentially operate them. When transitioning from OFF to ON, the mechanism closes S1, then actuate S2, and finally S3. When transitioning from ON to OFF, it opens S3, then actuate S2, and finally S1.

Description

AN ELECTRIC SWITCH FOR AC OR DC SUPPLYCROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY

[0001] The present application claims priority from Indian Patent Application No.202521005307, filed on January 22, 2025.FIELD OF INVENTION

[0002] The present invention relates to electric switches used with AC mains supply and DC supply, particularly switches fitted on wall panels or switchboards for controlling lights, fans, water heaters, and other AC & DC electrical loads. More specifically, the invention pertains to a contact mechanism for such switches that provides spark less and interference-free opening and closing of main contacts and series contacts, suitable for use with both AC and DC supplies, while addressing limitations of existing solutions.BACKGROUND OF THE INVENTION

[0003] Electric switches with movable contacts for opening and closing circuits to control electrical loads like lights, fans, and appliances are ubiquitous in residential, commercial, and industrial settings. These switches are typically mounted on wall panels or switchboards and are operated manually to turn loads on ON and OFF. While such switches generally function adequately in their fully open or closed positions, significant issues can arise during the transition between these states, especially when controlling larger electrical loads or in applications requiring frequent switching.

[0004] 1. Arcing and Its Consequences:

[0005] The primary problem that occurs during switching is arcing between the contacts as they separate or come together. When the switch contacts start to separate while carrying current, an arc can form across the small air gap created between the contacts. Similarly, when contacts are closing, an arc may jump across just before they make physical contact, particularly with capacitive load. Arcing problem is more sever while switching DC supply compared to AC supply as the AC voltage varies - follows sine wave & it reduces to zero every 10 ms ( with 50Hz supply). While switching load with DC supply spark takes more time till the contact are separated by distance sufficient to extinguish.

[0006] Arcing occurs because a voltage difference that exists between the separating contacts & also there will be further increase in the voltage due to inductance (opposing the change in current and generating back emf) in the contact circuit or the with the inductive load, that is sufficient toionise the air in gap and the current will flow through the ionised air generating a spark. The magnitude of spark generation depends (this voltage depends) on factors like Voltage, the load current, inductance in the circuit, apart from the breakdown strength of the insulating medium or the AIR and the speed of contact separation. In AC circuits, the likelihood and severity of arcing can vary depending on the point in the voltage waveform at which switching occurs. Sparking can occur with capacitive load at switching ON - closing of contacts.

[0007] The consequences of arcing are numerous and significantly impact the performance and reliability, of the switches and also the electrical safety

[0008] a) Contact Damage: The high temperature of the spark / arc erodes the contact surfaces, causing pitting, material transfer, and oxidation. This degradation of the contacts overtime reduces their lifespan and electrical performance. As the contact surfaces deteriorate, the resistance of the closed switch increases, leading to greater power dissipation and associated heat generation and potentially causing the contacts to weld together in severe cases.

[0009] b) Electromagnetic Interference (EMI): The rapid current changes during switching ON arcing generate broadband electromagnetic interference. This interference can affect nearby electronic devices, causing crosstalk -malfunctions in sensitive equipment or disrupting communications systems. In residential settings, this may manifest as noise in audio & video systems or interference with wireless networks. In industrial environments, EMI can disrupt control systems and cause data errors in automated processes.

[0010] c) Surge Currents: Particularly when closing contacts, large inrush currents can occur if contact is made at a peak of the AC voltage waveform. The magnitude of the surge current depends on the type of connected load. These surge currents can be several times higher than the steady -state current, stressing components throughout the electrical system. This can lead to nuisance tripping of circuit breakers, reduced lifespan of the switched loads, and in extreme cases, failure of the switch itself or connected equipment.

[0011] d) Safety Hazards: Severe arcing presents significant fire and shock risks, especially with older or damaged switches. The high temperatures generated during arcing can carbonize insulating materials, creating conductive paths that compromise the switch's isolation strength. In environments with flammable materials or explosive atmospheres, arcing switches pose a serious safety threat.

[0012] e) Power Quality Issues: The non-linear nature of arcs can introduce harmonics into the electrical system, potentially affecting power quality for other connected loads. This occurs only while switching the load and this can be particularly problematic in sensitive industrial processesor in buildings with a high density of electronic equipment & where there is a frequent switching ON & OFF of the load.

[0013] f) Acoustic Noise: The rapid heating and cooling of air during arcing can produce audible noise. While not typically a major concern in most applications, it can be a nuisance in quiet environments or in switches that are operated frequently.

[0014] 2. Traditional Mechanical Switches:

[0015] Conventional electromechanical switches, such as toggle switches, rocker switches, and basic relays, have been the mainstay of electrical control for decades due to their simplicity, low cost, and reliability and very low contact resistance in the closed state. These toggle & rocker switches operate by physically moving the rocker or the lever carrying moving contact together to closing a circuit and separating them to open it. A spring force ensures the contacts to remains in Close or Open state.

[0016] Advantages of traditional mechanical switches include:• Low on-state resistance, resulting in minimal power loss when closed• Simple construction and operation, leading to low manufacturing costs• No power consumption in the static (open or closed) state• Ability to provide visual confirmation of switch state• Familiar user interface for manual operation

[0017] However, these switches suffer from several limitations, particularly in applications involving higher currents or frequent switching:• Susceptibility to contact bounce during closure & opening , leading to multiple rapid makebreak events• Arcing during both opening and closing operations to the extent and depending on the type of connected load.• Wear of contact surfaces due to mechanical action and arcing• Relatively slow switching speed compared to solid-state alternatives• Limited lifetime in high-cycle applications• Generation of EMI & surge current during switching operations

[0018] 3. Solid-State Relays:

[0019] To address the limitations of mechanical switches, particularly in terms of arcing and EMI generation, solid-state relays (SSRs) have been developed and widely adopted in many applications. SSRs use semiconductor devices, typically triacs & Thyristors for AC loads or MOSFETs & IGBTs for DC loads, to control the flow of current without any moving parts.

[0020] Advantages of solid-state relays include:

[0021] a) Faster Reaction Time: SSRs can switch much more quickly than mechanical relays, often in few micro seconds. This rapid switching can be advantageous in applications requiring precise timing or high-speed control.

[0022] SSR can be switched at AC zero voltage or at Random. Switching at or near zero voltage with AC mains supply, reduces surge current and generation of EMI at Switch ON. Random switching is preferred for highly Inductive loads.

[0023] b) Absence of Voltage Bounce: Unlike mechanical switches, SSRs do not suffer from Voltage or contact bounce. When activated, the transition is smooth from the non-conducting to the conducting state without multiple make-break events. This eliminates a significant source of EMI and reduces stress on the load.

[0024] c) Sparkless Operation: Since there are no moving contacts, SSRs do not produce arcs during switching. This eliminates the associated contact wear, EMI generation, and safety hazards of arcing.

[0025] d) Long Operational Life: With no mechanical wear, SSRs can achieve very high cycle counts, often rated for millions of operations.

[0026] e) Compatibility with Control Systems: SSRs can be easily interfaced with electronic control systems, allowing for sophisticated control strategies and integration with automation systems.

[0027] However, solid-state relays also have several disadvantages:

[0028] a) Higher On-State Losses: The semiconductor devices in SSRs have a higher voltage drop when conducting compared to the near-zero resistance of closed mechanical contacts. This results in greater power dissipation and heat generation, particularly problematic for high-current applications.

[0029] b) Heat Sinking Requirements: Due to the power dissipation in the conducting state, SSRs often require heat sinks to manage temperature, increasing their size and cost, especially for higher current ratings.

[0030] c) Potential for Leakage Current: Even when in the off state, SSRs can allow a small leakage current to flow through the load. While usually negligible, this can be problematic in some applications, particularly those involving human safety.

[0031] d) Sensitivity to Voltage Transients: SSRs can be damaged by voltage spikes, and may require additional protection circuitry in harsh electrical environments to avoid malfunction / failure of control

[0032] e) Higher Cost: Generally, SSRs are more expensive than comparable mechanical relays, especially for higher power ratings.

[0033] f) Failure Mode: Unlike mechanical relays which typically fail open, SSRs can fail in either the open or closed state, which may have safety implications in certain applications. Relays fail by short in case carrying over current & welding of contacts due to the heat generation.

[0034] 4. Combined Electromechanical and Solid-State Solutions:

[0035] To combine the advantages of both mechanical switches and solid-state devices while mitigating their respective drawbacks, Combined solutions have been developed. These typically use a semiconductor device to temporarily carry the load current while the mechanical relay contacts open or close, thus eliminating arcing at the contacts.

[0036] Two main approaches have been used:

[0037] a) Parallel semiconductor switching element or Triac and Electromechanical Relay Configuration: In this arrangement, a triac (or two inverse-parallel connected thyristors for bidirectional switching) is connected in parallel with the contacts of an electromechanical relay. The operation sequence is as follows:

[0038] For turning on the load:1. The triac triggered at or near the zero-crossing of the AC mains voltage. (Switched as random for highly inductive load)2. Load current begins to flow through the triac, with minimal EMI generation due to the zero-voltage switching.3. The mechanical relay is the / n activated to close its contacts.4. Once the relay contacts are closed, they provide a lower-resistance path, and the triac ceases to conduct. Spark does not occur at this stage since the current is already passing through the load & the voltage difference across the contact of the relay is only the voltage across the Triac Or thyristor in ON state.5. The triac trigger signal is turned off by the control circuit (after @ 15 -20 milliseconds) & the Traic turns OFF naturally on current reaching zero, at next zero of A.C. Mains voltage.

[0039] For turning off the load:1. The triac trigger input is activated but Triac will not trigger as the load current is still passing through the relay contact & no voltage difference across the Triac terminals. 2. The relay contacts are opened, but no spark generated (arcless) as the voltage across the Triac begins to increase & immediately within few microseconds it gets triggered (turned ON) & the current starts flowing through the Triac to the connected load.3. The triac continues to conduct until the Triac trigger signal is disabled after some time (@15 - 20 milliseconds) by the control circuit.4. At next of A.C. mains voltage point, the triac naturally turns off on current reaching zero.

[0040] This approach effectively eliminates arcing at the relay contacts, significantly reducing EMI generation, contact wear, and the risk of contact welding and thus increases the life of relay contacts multiple times. Inversely relay of normal current rating can be used. It also minimizes surge currents during turn-on particularly for capacitive loads, by ensuring switching occurs near the zero-crossing of the voltage waveform.

[0041] b) Series-Connected Semiconductor switch and Electromechanical Relay: Another approach involves placing a semiconductor device (usually a triac for AC ) in series with the relay contacts. In this configuration:1. The semiconductor device is normally on, allowing current to flow.2. To open the circuit, the semiconductor is turned off first, interrupting the current.3. Once current flow has stopped, the relay contacts are opened with no arcing.4. To close the circuit, the relay contacts are closed first (with no current flow and thus no arcing).5. The semiconductor device is then turned on to allow current flow.6. With this approach there is a complete disconnection of power supply to the load. Any leakage current though the solid-state semiconductor will not pass through load as the series connected relay is open.7. This method also prevents arcing at the contacts but has the disadvantage of continuous power dissipation in the semiconductor device when the switch is closed.

[0042] Advantages of Combined solutions:• Near-elimination of arcing at electromechanical relay contacts• Reduced EMI generation compared to pure electromechanical switches• Lower continuous power dissipation compared to pure solid-state relays• Ability to handle higher currents without large heat sinks• Increased lifetime of mechanical contacts due to spark less opening, closing of contacts, and reduced wear.• Effects of contact bounce are surpassed due to the electronic control circuit as during contact bounce, the solid-state semiconductor is in ON state or conducting stage.Disadvantages of Combined solutions:• More complex and expensive than simple mechanical switches• Require a control circuit to manage the switching sequence• Often need a separate power supply for the control circuit• May require connection to the neutral line, which is not always available at the switch location• Larger size compared to simple switches due to the additional components

[0043] The present invention aims to address these needs by providing a novel contact mechanism eliminating the need for electromechanical relay that combines the benefits of mechanical and solid-state switching techniques of both - i.e. series connected & parallel connected approach while overcoming the limitations of existing combined solutions. By doing so, it seeks to offer a superior switching solution that can be widely adopted, improving electrical safety, energy efficiency, and device longevity across a broad range of applications.SUMMARY OF THE INVENTION

[0044] This summary is provided to introduce the concepts related to an electric switch used with AC mains supply and DC supply and the concepts are further described in the detailed description. This summary is not intended to identify essential features of the claimed subject matter, nor it is intended to be used in determining or limiting the scope of the present subject matter.

[0045] In one embodiment, an electric switch for controlling current flow to a load from power source is disclosed. The electric switch comprises a first contact (SI) or series contact for isolating the switch from a power supply, a second contact (S2) for controlling a solid-state switching element, and a third moving contact (S3) or parallel contact for bypassing the solid-state switching element including SI and connecting externally to the Load. Furthermore, the electric switch comprises a solid-state switching element connected in parallel with Sla power source and S3 a, wherein S3a is connected to a Load point, wherein when SI gets closed then it gets connected to power source as spring 64 carrying Sib is connected to phase point, wherein the third moving contact (S3) is connected in parallel with solid state switching element or solid-state switching element including series contact SI. Furthermore, the electric switch comprises a control circuit electrically connected to point (S2a) and point (S2b) of the second contact (S2) for controlling the operation of the solid-state switching element and a delay mechanism mechanically coupled to the first contact (SI), second contact (S2), and carrying third moving contact (S3) for sequentially operating said contacts (SI, S2, and S3) one after the other, wherein the delay mechanism is configured to introduce delay in sequential operation between said contacts (SI, S2, and S3).BRIEF DESCRIPTION OF DRAWINGS

[0046] The detailed description is described with reference to the accompanying figures. The same numbers are used throughout the drawings to refer like features and components.

[0047] Figure la and lb illustrates different views of an electric switch (100), in accordance with an embodiment of the present subject matter;

[0048] Figure 2a and 2b illustrates exploded view of delay mechanism in the electric switch (100) and figure 2c illustrate stage wise different positions of the main levers (30, 40), in accordance with an embodiment of the present subject matter;

[0049] Figure 3 illustrates sectional views of the parts of electric switch (100), in accordance with an embodiment of the present subject matter;

[0050] Figure 4a and 4b illustrates one-way and two-way switch arrangement of the electric switch (100) with NO type contact, whereas Figure 4c illustrated one-way with NC type contact, in accordance with an embodiment of the present subject matter; and

[0051] Figure 5 illustrates working of a speed deceleration mechanism (500) enabled in the electric switch (100), in accordance with an embodiment of the present subject matter.DETAILED DESCRIPTION OF THE INVENTION

[0052] Reference throughout the specification to “various embodiments,” “some embodiments,” “one embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one of the embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment,” or “in an embodiment” in places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. The following is an example which is illustrative only and the invention accommodates any and every variation of the example provided below that shall serve the same purpose and is obvious to a person skilled in the art.

[0053] Figure la and lb illustrates different views of an assembled electric switch (100), in accordance with an embodiment of the present subject matter. The electric switch (100) is designed to fit within a standard wall-mounted electrical box and comprises an outer housing or casing with a half-round cap on the top side, made of plastic molding.

[0054] The switch (100) features two knobs (10, 20) on its top side for manual operation, with knob (10) used for switching ON and knob (20) for switching OFF in case of a one-way switch configuration. The two knobs (10, 20) may be used for toggling between two lights case (loads) of a two-way switch configuration. The switch housing includes terminals strategically placed at the bottom - terminal (108) for A.C. Mains phase connection or DC +Ve of the DC supply fromthe power supply and terminal (107) for connecting to the load (with an additional terminal (109) for two-way switch configuration). Typical locations of terminals are as shown, but may change based on PCB component and track layout.

[0055] A printed circuit board (PCB) is housed within the casing, containing the solid-state switching element and associated control circuitry. The control circuit may be configured for AC zero voltage triggering or random triggering and also for use with DC loads. The switch (100) also includes a visual indicator, implemented using LEDs (103), visible through a small transparent window in the top half-round cap to indicate the switch's operational status.

[0056] The switch (100) incorporates a sophisticated delay mechanism that ensures sequential operation of the contacts with appropriate timing delays. While externally appearing similar to conventional switches, this design enables spark-free and interference free switching operations for both AC mains and DC power supplies for wall-mounted or panel mounted applications.

[0057] The switch incorporates a sophisticated visual indicator system that provides clear feedback about its operational status. For AC power supply applications, this system consists of two LEDs connected in inverse parallel, while DC power supply applications utilize a single LED. These LEDs are electrically connected to the control circuit and are designed to indicate both the status of the solid-state switching element and the switch position during ON / OFF operations.

[0058] The switch housing (105) is constructed with careful attention to space efficiency and functionality. The housing (105) is covered with a half-round cap (102) on the top side. The housing includes strategically placed external terminals for power and load connections.

[0059] In continuation to figure 1, figure 2a, 2b, 2c, 3 and 4 now discloses an exploded view of the electric switch mechanism (100) that illustrates the detailed arrangement of components for controlling current flow to a load from a power source. The figure shows three essential contact assemblies that work together in a coordinated sequence: the first contact (SI) or series contact, which serves as an isolation mechanism from the power supply and prevents any leakage current from the solid state switching element from passing through the load when the switch is in OFF state; the second contact (S2), which controls the solid-state switching element; and the third moving contact (S3) or parallel contact, which functions as a bypass for the solid-state switching element and provides an external connection to the load.

[0060] The figures reveal how the arrangement is designed such that when contact SI closes, it establishes a connection to the power source as contact point Sib, mounted on spring 64, is connected to the phase point. Furthermore, the third moving contact (S3) or parallel contact for bypassing the solid-state switching element including SI and connecting externally to the Load.A control circuit, which is electrically connected to points S2a and S2b of the second contact (S2), can be seen positioned to effectively control the operation of the solid-state switching element.

[0061] A key feature illustrated in the exploded and Figure 4 view is the delay mechanism that coordinates the movement of all three contacts. This mechanism is mechanically coupled to the first contact (SI), second contact (S2), and third moving contact (S3), enabling them to operate sequentially one after another. The detailed construction shows how the mechanism is specifically configured to introduce precise minimum required delays between the operation of these contacts, ensuring proper timing and sequencing during both switch-on and switch-off operations.

[0062] The exploded view particularly emphasizes how each contact assembly is positioned and how they interact with the delay mechanism to achieve the required sequential operation. This view helps visualize how the mechanical coupling enables smooth transition between states while maintaining the necessary isolation, control, and bypass functions of the respective contacts.

[0063] In continuation to the basic functionality described above, figure 2a and figure 4 further illustrates the specific configuration of the delay mechanism that controls the precise sequencing of contact operations. The exploded view reveals how the mechanism is engineered to handle normally open (NO) configurations of contact S2.

[0064] For transitions from OFF to ON position with a NO type S2 contact, the mechanism is arranged to first close the first contact (SI), followed by closing the second contact (S2), and finally closing the third moving contact (S3) to complete the switch ON cycle. Alternatively, when configured with an NC type S2 contact, the sequence begins similarly with closing contact SI, but then opens contact S2, before finally closing contact S3 to complete the ON cycle. The specific arrangements of the first contact (SI), the second contact (S2), and the third moving contact (S3) is further explained with respect to figure 4.

[0065] The figure also shows how the mechanism reverses these sequences during ON to OFF transitions. With NO type S2 contact, the mechanism is structured to first open contact S3, then open contact S2, and finally open contact SI to complete the switch OFF cycle. For NC type S2 contact configuration, the sequence begins with opening contact S3, proceeds to close contact S2, and concludes with opening contact SI to complete the OFF cycle. The delay mechanism is such that all three steps of switching takes place in sequence by pressing the knob simply once at switching ON & once at switching OFF.

[0066] The exploded view particularly emphasizes the mechanical components that enable this precise sequencing, showing how S2 can be configured as normally open contact through specific positioning and arrangement of its contact points. This adaptable design allows the switch to beconfigured for different applications while maintaining the critical timing and sequencing requirements for proper operation.

[0067] A critical connection point (51) is clearly illustrated, where the power source connects to both the flexible connection strip (60) and the cantilever beam spring (64) that carries contact Sib.

[0068] The figure lb particularly demonstrates the sophisticated design consideration for DC supply applications, showing the provision for connecting a separate DC low voltage supply to power the control circuit. This is implemented through a miniature connector, preferably of the FRC type, which is strategically positioned on the rear-top side (106) of the switch housing. This arrangement becomes especially important in configurations where the load power supply and control circuit power supply are different, ensuring proper isolation and functionality.

[0069] The Prospective View details how this dual power supply capability is integrated into the switch's mechanical structure, with the connector placement carefully considered to maintain the switch's compact form factor while ensuring accessibility for installation and maintenance.

[0070] Figure 2a and figure 4 provides a detailed illustration of the switch's flexible connection system and contact arrangements. The view shows how the flexible connection (60) made of flexible copper foil strips is precisely configured around the main bracket (50), with its centre portion (M to N) wrapping around section E to F of the bracket. This central portion is securely fastened by a rivet at point (51) using a clamp (52), which creates a rigid connection that internally links to external terminal 108 for power supply connection.

[0071] Figure 4 further reveals the comprehensive delay mechanism components and their intricate arrangement. The main bracket (50) with a modular design serves as the foundational element, shown with all its mounting points and guide features for supporting the mechanism's various components in its relative positions. On this bracket, two main levers (30, 40) are pivotally mounted at projection points A and B respectively. For one-way switch operation, lever (30) is designated for switching ON and lever (40) for switching OFF, while in two-way configurations, both levers can perform either switching function.

[0072] Manual operation knobs (10, 20) are depicted mounted atop their respective main levers.

[0073] Figure 2b shows use of the torsion spring (66), while figure 2a illustrates an alternative spring configuration where the torsion spring (66) is replaced by a cantilever beam spring (63), while maintaining all other components in their original arrangement. This cantilever beam spring (63) is fabricated from flat strip of spring material and is engineered as a single unified piece that serves both main levers (30, 40), representing a significant design simplification over the previous torsion spring assembly. Furthermore as illustrated in figure 4 the middle portion of the cantilever beam spring (63) is securely clamped by clamp (52) at the top centre (51) of the main bracket (50),sharing this mounting point with the flexible connection (60) and cantilever beam spring (64). From this central mounting point, the spring extends to both sides, with its free ends rigidly attached to the main levers (30, 40) at points KL and OP respectively. This arrangement ensures balanced spring force distribution to both levers.

[0074] Figure 2c and figure 3 further details, the bistable latching mechanism, showing the matching radius profiles on both main levers at two places that engage with each other in stable positions. The figure 3 reveals the cam profile (31) on lever (30) interacting with the stroke profile (42) on lever (40), and alternatively, cam profile (41) on lever 40 engaging with stroke profile (32) on lever (30). The torsion spring assembly (66) comprises two torsion springs (66, 66’) is shown comprising two separate springs (66a, 66b) wound in opposite directions, sharing a common leg (67). Their other legs (68a, 68b) rest on projections (39, 49) of the main levers respectively. There are two torsion springs (66, 66’) assembled on the two sides of both main levers (30, 40). The torsion spring (66) may be made from a spring steel wire.

[0075] Further, Figure 2a illustrates notable improvement of the elimination of pivot points A and B and their associated pivot pins (37, 37’, 47, 47'), torsion spring (66a and 66b) seats (38, 38, 48, 48’) and the projections (39, 39’, 49, 49’) on both sides of main levers (30, 40). Also, the previous design's projections (55, 55') on the side of the main bracket, which were necessary for supporting the pivot pins when using spring (66), are no longer functionally required with the cantilever beam spring configuration. This elimination of pivot points and pins represents a significant simplification in the mechanism's design, potentially reducing wear points and improving long-term reliability.

[0076] The figure demonstrates how this alternative spring arrangement maintains the same switching functionality and sequential operation as the torsion spring design, while offering a more streamlined mechanical configuration with fewer components and fewer potential failure points.

[0077] In continuation to figures 2a and 2b, figure 2c illustrates the five distinct transition stages (200a, 200b, 200c, 200d, 200e) that demonstrate the movement and interaction between main levers (30, 40) during switching operations. These stages depict how the delay mechanism, mounted on main bracket (50), orchestrates the precise sequencing of operations.

[0078] Stage 200a shows the initial stable position where both main levers (30, 40) are at rest, with their respective knobs (10, 20) in position for manual operation.

[0079] In stage 200b, lever (30) begins its clockwise rotation while lever (40) remains stationary. The bistable latching mechanism shows how the stroke profile (42) on lever (40) rests against the cam profile (31) on lever (30). During this stage, the torsion spring (66) with common leg (67), begins to wind as lever (30) rotates.

[0080] Stage 200c depicts the critical moment when lever (40) becomes unlocked. At this point, the torsion spring's legs (68a, 68b), resting on projections (39, 39’, 49, 49’) of the main levers, drive the transition. The speed deceleration mechanism (500) begins controlling the movement to ensure proper timing delays between contact operations.

[0081] In stage 200d, lever (40) rotates clockwise while lever (30) remains stationary, demonstrating how the delay mechanism maintains stable positions during transitions.

[0082] The final stage 200e shows the completion of the transition, where both levers have reached their new stable positions. In the case of a two-way switch configuration, both levers (30, 40) can be seen positioned to enable either ON or OFF operations, with the flexible connection (60) now common to both levers and extending to contacts S3b and S3 'b .

[0083] With reference to figure 3, torsion spring (66) gets released in two scenarios: first when lever (40) unlocks and rotates clockwise while lever (30) remains stationary, and second when lever (30) unlocks and rotates anticlockwise while lever (40) stays in place.

[0084] The Figure 4 further details how main lever (40) is equipped with a parallel contact point S3b that engages with fixed contact point S3a, which is rigidly mounted to the main bracket (50) for one-way switch configurations. For two-way switch setups, the figure shows how main lever 30 similarly carries a parallel contact point S3 ’a. The fixed contact point S3a is internally connected to both the external terminal for load connection and the appropriate end of the solid-state switching element.

[0085] These mechanical arrangements are shown in precise detail, in figure 4 illustrating how each component contributes to the switch's overall functionality while maintaining proper electrical isolation and ensuring reliable contact engagement throughout the switching operations. The Figure 4 particularly emphasizes how these various elements work together to provide smooth mechanical operation while maintaining proper electrical continuity where required.

[0086] The Figure 4 demonstrates how the spring (66, 63) arrangement holds the levers in their latched and stable states. When lever (30) turns clockwise, lever (40) remains stationary with stroke profile (42) resting on cam profile (31) as the spring winds / deforms. Similarly, when lever (40) turns anticlockwise, lever (30) stays fixed with stroke profile (32) against cam profile (41) while the spring winds / deforms. The spring (66, 63) gets released when lever (40) unlocks and rotates clockwise while lever (30) remains stationary, and when lever (30) unlocks and rotates anticlockwise while lever (40) stays in place.

[0087] The figure 4 also details how vertical edges (21, 22) near the main bracket's center-line restrict the extra movement of both main levers at the end of their strokes during manual operation. In case of one way switch, main lever (30) rests on stopper (54) when the switch is in OFF state.Finally, the speed deceleration mechanism (500) is illustrated, showing how it controls the main levers' movement to ensure minimum required time delays between contact operations. This occurs after lever 40 unlocks and rotates clockwise before contact S3 closes during switch ON, and after lever 30 unlocks and rotates anticlockwise before contact SI opens during switch OFF, maintaining consistent operation and works as common in both one-way and two-way configurations. This delay is essential for avoiding generation of sparks during Opening and closing of contacts.

[0088] The figure 4 reveals the intricate design of the flexible connection's free portions (N to O and L to M), which are guided by specially curved surfaces G-H on the main bracket (50) to accommodate the rotation of main levers (30, 40). The curved surface (arc) on the main bracket passes through the two pivot points A and B. For one-way switch configurations, portion OP is shown rigidly attached and bent to reach contact point S3a, while in two-way configurations, both portions KL and OP are similarly attached and bent to reach contacts S3a and S3’a respectively.

[0089] A critical component detailed in the exploded view is the cantilever beam spring (64), which is manufactured from electrically conductive spring material. The figure 4 shows how one end of this spring is securely clamped by clamp 52 at point 51 on the main bracket 50, sharing this mounting point with the common flexible connection (60) that carries the power supply. The other end of the spring terminates in contact point Sib. The view illustrates how this spring is designed to rest on points (33, 33') on main lever (30) through spring force when the switch is in its OFF position. When knob (10) is operated, rotating main lever (30), the drawing shows how contact point Sib moves to meet fixed contact point SI a, closing contact SI. Then onwards, this contact remains closed throughout the switch's ON state, with the fixed contact point Sla internally connected to an appropriate end of solid-state semiconductor mounted on the PCB below.

[0090] In continuation to previous figures, figure 4 illustrates detailed sectional views showing two distinct configurations for operating contact S2: one for normally closed (NC) type contact and another for normally open (NO) type contact. More specifically, figure 4a illustrated one way S2 NO contact arrangement, figure 4b illustrated two way with S2 NO contact arrangement, and figure 4c illustrated one way with S2 NC contact arrangement.

[0091] For the NC type contact configuration, the figure shows two contact strips (71, 72) positioned vertically near the main bracket's (50) centerline, specifically located on one side widthwise. These contact strips, manufactured from electrically conductive spring material, carry crossbar type contacts at points S2a and S2b. The lower ends of these contact strips are firmly fixed and electrically connected to the control circuit on the PCB below. A critical operating component illustrated is the projection (75) extending from the lower end of main lever (40). During switch-off operations, before end of its stroke this projection makes contact with and pushes contact strip (71), causing contact S2 to close. Conversely, during switch-on operations, the contact strips (72, 71) are shown moving to open contact S2, coming to rest against their respective stoppers (73, 74), wherein these NO & NC contact arrangement as shown in the figures 4 is directly implemented, wherein it can be implemented using a miniature micro switch also.

[0092] For two-way switch configurations, the figure reveals how this arrangement is mirrored on both sides of the main bracket, while one-way switches utilize only one side. The cross-bar type contact design is clearly depicted, showing how the two contact bars meet at a right angle. This innovative design feature is shown reducing the contact area while ensuring optimal contact matching and enhanced reliability with low operating current, this design effectively minimizes the risk of contact failure from foreign matter entry.

[0093] In the NO type contact configuration, the figure illustrates a different arrangement where a fixed contact bar S2a is supported by projection (78) on the main bracket (50), positioned at the lower portion on one side of the vertical centre line, wherein the fixed contact S2a is internally connected on the PCB. A cantilever spring strip 79, made of electrically conductive spring material and carrying contact bar S2b, is shown with its lower end connected to the PCB. The upper portion of this cantilever spring strip 79 is positioned to interact with projection (75) on the lower portion of main lever (40).

[0094] The operational sequence for the NO configuration shows how during switch-off, just before end of stroke of main lever (40) projection (75) pushes and maintains pressure on the cantilever spring strip, keeping contact S2 in the open position. During switch-on, as main lever (40) rotates clockwise, the figure demonstrates how the cantilever spring strip is released, allowing contact point S2b to naturally engage with contact point S2a through spring force.

[0095] Similar to the NC configuration, this arrangement is shown implemented on one side for one-way switches and on both sides of main bracket - width wise for two-way switches, maintaining the same cross-bar contact design benefits of reduced contact area, improved contact matching, and enhanced reliability with low operating current through reduced susceptibility to foreign matter interference. The contact arrangement for NC & NO type are shown here in is as implemented directly. This may be implemented using miniature Micro switch also.

[0096] The spring material of contact strips (71, 72, 79) serves both mechanical and electrical functions, providing the necessary flexibility for reliable operation while ensuring good electrical conductivity.

[0097] Figure 4b further illustrates the configuration of a two-way switch arrangement, showing how the basic switch mechanism is adapted for bi-directional operation. The figure reveals asymmetrical design where additional contacts SI', S2', and S3' are arranged as mirror images of the original contacts SI, S2, and S3 respectively.

[0098] The main bracket's design is prominently displayed, showing a common layout that accommodates all fixed contacts: Sla, Sl'a, S2, S2', S3a, and S3'a. This unified layout demonstrates efficient space utilization while maintaining proper electrical isolation between contacts. The positioning of contact S2 on one side of the main bracket and contact S2' on the opposite side is clearly illustrated, showing how this arrangement allows for independent operation from either direction.

[0099] A key feature detailed in the figure is the cantilever leaf spring arrangement. This spring, which carries contact Sib (64) for one way configuration, is shown extended to include operation of contact SI' with the opposite main lever. The innovative design shows how a single strip of spring material is used to create a common cantilever leaf spring, with its middle portion securely clamped at the top by clamp 52. From this central mounting point, the spring extends to carry contact Sib on one side and contact Sl'b on the other side, for two way configuration, ensuring balanced operation in both directions.

[0100] The figure also demonstrates how the delay mechanism remains unchanged from the oneway configuration, yet effectively controls the timing of both switching directions. This common delay mechanism is shown interfacing with both sets of contacts, maintaining proper sequencing regardless of which direction the switch is operated from.

[0101] In continuation to previous figures, figure 5 provides a comprehensive illustration of the speed deceleration mechanism (500), which is crucial for ensuring timing control and ensure minimum required delay during switching operations. This sophisticated mechanism is designed to maintain two critical time delays: a first-time delay of at least 10 milliseconds between S2 activation and S3 closing during OFF to ON transitions, and a second time delay of at least 10 milliseconds between S2 activation and SI opening during ON to OFF transitions.

[0102] The foundational structure of the mechanism is built around two rocking plates (96, 96') that are pivotally mounted on fixed points (57, 57') located on the bottom portion of the main bracket (50). These rocking plates provide the basic framework for the deceleration system and are designed for angular movement with its centre at grooves (57, 57’) during operation. Above these rocking plates sits a top plate (90), which is supported through specially designed V-slots (98, 98'). These V-slots allow the top plate to maintain stable contact with the rocking plates while enabling smooth horizontal movement.

[0103] The force control system of the mechanism is implemented through two springs (99, 99'). The lower ends of these springs are securely attached to fixed points (59, 59') on the main bracket(50), while their upper ends are hooked into precise grooves (97, 97') located at the top comers of the top plate (90). The attachment is accomplished using pins through eye-type hooks on both sides of the springs, ensuring secure and reliable spring operation. This spring arrangement is critical for providing the controlled resistance necessary for proper speed deceleration of the main levers (30, 40)

[0104] The top plate (90) features several precisely engineered surfaces that facilitate its operation. On its top side, there is a step (91) with two faces (95, 95') that interact with the main levers. The main lever (40) includes a projected portion (45) with face (46) designed to contact face (95) of the top plate, while main lever 30 has a projected portion 35 with face 36 that contacts face (95') during operation. These contact surfaces are crucial for translating lever movement into the movement of top plate 90 and controlled deceleration.

[0105] To prevent over-travel and ensure proper positioning, the mechanism includes a stopper (58) that projects from the main bracket (50). This stopper has faces (94, 94') that limit the movement of the top plate (90). Corresponding to these stopper faces, the top plate has a step (92) on its lower side with step faces (93, 93') that rest against the stopper faces when the plate shifts from right to left or left to right.

[0106] The operation of the mechanism is precisely orchestrated to provide controlled speed deceleration in both directions. During horizontal reciprocation, the top plate (90) moves between two extreme stable positions. This movement requires a force as the springs (99, 99') gets stretched, creating an opposing torque on main lever 40 during right-to-left movement and on main lever 30 during left-to-right movement. As the rocking plates approach their vertical position, the spring force gradually increases and reaches maximum and then gradually decreases again.

[0107] The step faces (93’) on the lower side of top plate (90) are precisely engineered to rests on the stopper faces (94’) when the top plate shifts from right to left. Similarly, step face ' (93) engages or rests on stopper face (94) during left-to-right movement. This interaction ensures precise positioning at the extremes of travel while maintaining proper alignment throughout the reciprocation cycle.

[0108] A crucial feature of the mechanism is its ability to release the main levers at the appropriate moment. The main lever (40)'s face 46 disengages from face 95 (or main lever 30's face 36 from face 95') before the end of its stroke. This timing feature ensures that full spring force (whether from spring 66 or 63) is applied when contacts S3 or S3' gets closed, maintaining proper contact pressure.

[0109] The mechanism effectively lowers the initial velocity of main lever (40) as it starts rotating clockwise during switch-ON operations. This deceleration delays the closing of contactS3 due to the opposing torque created by the mechanism. Similarly, during switch-OFF operations, it reduces the initial velocity of main lever 30 starts rotating anticlockwise, thereby delaying the opening of contact SI through the same opposing torque principle.

[0110] An important design consideration is that the speed deceleration mechanism (500) works in isolation of the lever (30) and (40) i.e. it is not connected anywhere with the main levers (30, 40). The top plate 90 does not interfere with manual operations. When manually operating lever 30 for switch ON or lever 40 for switch OFF, the top plate remains clear of the lever projections. The top plate only engages when lever 40 is released from the latch and begins rotating clockwise during switch ON, or when lever 30 is released and starts rotating anticlockwise during switch OFF. In other words no extra effort is required while manually pressing on the knob (at switch ON or OFF) due to the speed deceleration mechanism (500).

[0111] The entire delay mechanism works together to ensure the required minimum delay of 10 milliseconds between contact operations during both switch-ON and switch-OFF transitions. This timing is critical for proper switch operation and is maintained consistently whether in one-way or two-way switch configurations. The mechanism's design demonstrates controlling the movement of the main levers, ensuring reliable and consistent switching operations while supressing the effects of contact bounce and maintaining proper electrical isolation.

[0112] Through this sophisticated arrangement of mechanical components, the speed deceleration mechanism (500) successfully manages the critical timing requirements for both switch-ON and switch-OFF operations, contributing significantly to the overall reliability and performance of the electric switch. The mechanism's ability to maintain consistent timing delays while accommodating manual operation makes it an essential component of the switch's design. Furthermore, the contact life is increased by manifolds due to the spark free operation. As a result, contact of normal rating can be used and there is no need for using over rated contacts.

[0113] In case of switch for AC mains supply the solid-state switching element is required to turn on or trigger at or near zero crossing of the AC supply voltage. The next zero crossing point can occur any time within maximum 10 ms after enabling the trigger signal i.e. after activating contact S2 so that the load current starts passing through the solid-state element and the contact S3 gets closed after that. The delay mechanism provides this required delay for spark free & EMI free contact closing and opening.

[0114] Similarly, at switch OFF when Contact S3 gets open, spark does not occur as the load current immediately starts to pass through the solid-state switching element. At the time of switching OFF after contact S2 is activated the solid-state switch naturally stops conducting on current reaching zero, within maximum 10 ms. Thus, when contact SI gets open the spark doesnot occur. Similarly, arcing at the time of contact opening or closing that might occur during contact bounce are also suppressed. Alternatively, this arrangement also permits suppression of arcing as might otherwise occur during contact bounce.

[0115] Furthermore, the contact life is increased by manifolds due to the spark free operation. As a result, contact of normal rating can be used and there is no need for using over rated contacts.

[0116] There is additional advantage of reduction in the surge current at switch ON associated with the interference free switching, as the switching ON takes place near zero voltage. The reduction in the surge current greatly reduces the stress on the component / equipment which is connected to, at switch ON. This increases the life of the connected equipment & also the semiconductor components used in connected equipment.

[0117] In an embodiment, a series resistance may be used in series with the solid-state switching element and series contact SI for surge current reduction. With the use of delay mechanism and speed deceleration mechanism 500, series resistance can be used with advantage for surge current reduction at switch ON cycle till closing of contact S3 as it is delayed before it gets closed, thus the load current passes through the series resistance till that time.

[0118] In practice the material as well as dimensions, could be of any type according to the requirements and the state of art.

[0119] It will be apparent to those skilled in the art that various modifications and variations can be made to the present Invention without departing from the spirit and scope of the invention. There is no intention to limit the Invention to the specific form or forms disclosed but on the contrary, the intention is to cover all the modifications, alternative constructions and equivalents falling within the spirit and scope of the Invention, as defined in the appended claims. Thus, it is intended that the present Invention cover the modifications and variations of this Invention provided they come within the scope of appended claims and their equivalents.

Claims

AMENDED CLAIMSreceived by the International Bureau on 25 May 2026 (25.05.2026)1. An electric switch (100) for controlling current flow to a load from power source, comprising:a first contact (S 1) or series contact for isolating the switch from a power supply, wherein the first contact (SI) comprises a pair of mating contact points (Sla) and (Sib) that make physical contact when closed;a second contact (S2) for controlling a solid-state switching element, wherein the second contact (S2) comprises a pair of mating contact points (S2a) and (S2b) that make physical contact when closed;a third moving contact (S3) or parallel contact for bypassing the solid-state switching element including S 1 and connecting externally to the Load, wherein the third moving contact (S3) comprises a pair of mating contact points (S3a) and (S3b) that make physical contact when closed, wherein the contact point (S3b) is connected to power source via a flexible connecting strip 60, wherein the contact point (S3a) is internally connected to load terminal as well as to one end of a solid state switching element;characterized in that:the solid-state switching element is connected in parallel with the contact point (Sla) and the contact point (S3 a), wherein the contact point (S3b) provides a direct connection from the power source to the load when closed, bypassing the solid-state switching element including first contact (SI), wherein when first contact (SI) gets closed then contact point (Sla) gets connected to power source as spring 64 carrying contact point (Sib) is connected to phase point or power source;a control circuit electrically is connected to contact point (S2a) and contact point (S2b) of the second contact (S2) for controlling the operation of the solid-state switching element; anda delay mechanism comprising mechanically linked components coupled to the first contact (SI), second contact (S2), and carrying third moving contact (S3) for sequentially operating said contacts in a predetermined order with controlled timingduring switch-on and switch-off operations, wherein the delay mechanism is configured to introduce delay in sequential operation between said contacts (SI, S2, and S3).

2. The electric switch (100) of claim 1, wherein the delay mechanism is configured to:when transitioning from the OFF position to the ON position in case of NO type S2 contact, close the first contact (SI), then close the second contact (S2), and finally close the third moving contact (S3) thereby completing the switch ON cycle, when transitioning from the OFF position to the ON position in case of NC type S2 contact, close the first contact (SI), then open the second contact (S2), and finally close the third moving contact (S3) thereby completing the switch ON cycle;when transitioning from the ON position to the OFF position in case of NO type S2 contact, open the third moving contact (S3), then open the second contact (S2), and finally open the first contact (SI) thereby completing the switch OFF cycle, when transitioning from the ON position to the OFF position in case of NC type S2 contact, open the third moving contact (S3), then close the second contact (S2), and finally open the first contact (SI) thereby completing the switch OFF cycle, wherein when the switch is in OFF state the second contact S2 is configured as either a normally open (NO) contact or a normally closed (NC) contact implemented either directly through contact points (S2a) and (S2b) attached to the spring strips (71, 72) respectively in case of NC or contact point (S2b) to spring strip (79) in case of NO or using a commercially available miniature micro switch; andwherein the first contact (SI) is a series switch provided for complete disconnection of the switch from power supply and also to prevent leakage current if any from the solid-state switching element passing through the connected load when the switch is in the OFF state.

3. The electric switch (100) of claim 1, wherein the power source is AC Mains ( 50 Hz or 60 Hz) power supply or DC power supply wherein the power source is connected at point 51 to the flexible connection strip 60 and cantilever beam spring 64 carrying contact Sib together, wherein the control circuit is optionally powered by a separate DC low voltage supply through a connector when the load operates on adifferent power source, wherein a male part of a miniature connector, preferably FRC type, is provided on the rear-top side (106) on the switch housing.

4. The electric switch (100) of claim 2, wherein(a) the centre portion M to N of the flexible connection (60) around portion E to F of the main bracket (50) is rigidly connected at the centre portion (51) of the main bracket (50) by a clamp (52) and is internally connected to an external terminal 108 for connecting to the power supply;(b) portions N to O and L to M of the flexible connection (60) remain free and are guided by a curved surface G-H on the main bracket (50) when the main levers (30, 40) rotates;(c) portions OP for one-way connection, and KL and OP, for two-way connection are rigidly attached to the main levers (30, 40), wherein flexible connection (60) is common for main levers (30, 40) for two-way connection and bent further on lower side;(d) for one way switch, a cantilever beam spring (64) made of electrically conductive spring material, wherein one end of the cantilever beam spring (64) is fixed or clamped by clamp 52 on the main bracket 50 at 51, along with the common flexible connection (60) carrying the power supply, and wherein other end is a contact point Sib for one way switch configuration, wherein the flexible connecting strip (64) rests on points (33, 33') on the main lever (30) by spring force when the switch is in OFF position, wherein when the knob (10) rotates with the main lever (30), the contact point Sib comes in contact with a fixed contact point SI a, closing contact SI wherein when main lever (30) rotates further, contact SI remaining closed as long as the switch is ON state, wherein the fixed contact point Sla is internally connected to one end of a solid state semiconductor on a PCB below.

5. The electric switch (100) of claim 1, wherein the delay mechanism comprises:(a) a main bracket (50) for holding other parts of the delay mechanism in relative position and guiding during its movement;(b) two main levers (30, 40) pivotally mounted on the main bracket (50) on two projections (55, 55’) at pivot points A and B respectively when torsion spring 66 is used, wherein in case of one-way switch configuration, the first lever (30) is dedicated for switching ON and the second lever (40) is dedicated for switching OFF, whereas in case of two-way switch configuration, both levers can function for either switching ON or OFF depending on their position;(c) knobs (10, 20) fixed on top of the main levers (30, 40) respectively for manual operation;(d) a bistable latching mechanism, wherein the bistable latching mechanism comprises profiles of the same radius at two places on both main levers (30, 40) that remain engaged with each other in one of the two stable positions, a cam profile (31) on the main lever (30) and a stroke profile (42) on the main lever (40), or a cam profile (41) on main lever 40 and stroke profile (32) on main lever (30);(e) a torsion spring (66) comprising two separate torsion springs (66a, 66b) wound in opposite directions with a common leg (67), wherein other legs (68a, 68b) of the torsion springs rest on projections (39, 39’, 49, 49’) on the main levers (30, 40) respectively, wherein the two separate torsion springs (66a, 66b) are mounted at the torsion spring seats (38, 38’ 48, 48’) near pivot pins (37, 37’ 47, 47’) on both sides of the main levers (30, 40) respectively, wherein the torsion spring (66) holds the main levers (30, 40) in one of the two latched and stable states, and also allowing the levers to rotate and remain in one of the two stable positions when locked, wherein when lever (30) is turned clockwise, lever (40) remains stationary with stroke profile (42) resting on the cam profile (31), and the spring gets wound, and wherein when lever (40) is turned anticlockwise, lever (30) remains stationary with stroke profile 32 resting on cam profile (41) and the torsion spring (66) gets wound, wherein the torsion spring (66) gets released when lever (40) is unlocked and rotates clockwise and lever (30) is stationary and also when lever (30) is unlocked and rotates anticlockwise and lever (40) is stationary, wherein extra movement of both the main levers (30, 40) at the end of its stoke, when operated manually, is restricted by the vertical edges 21 and 22 near vertical centreline of main bracket (50), wherein two torsion springs (66, 66’) are assembled on the two sides of both main levers (30, 40); and(f) a speed deceleration mechanism (500) controls the movement of main levers (30, 40) to ensure minimum time delays between contact operations after main lever 40 is unlocked and starts rotating clock wise before contact (S3) gets closed or before contact (ST) gets opened and after main lever 30 is unlocked and starts rotating anticlockwise before contact (SI) gets opened or contact (S3’) gets closed.

6. The electric switch (100) of claim 2, further comprising a mechanism to operate contact S2, wherein for NC type contact,(a) two contact strips (71, 72) carrying contact point S2a and contact point S2b of S2 are positioned vertically near the vertical centre line of the main bracket (50) and on one side of main bracket —width wise;(b) the contact strips (71, 72) are made of spring material and carry contact points (S2a, S2b), wherein the material of the contact strips (71, 72) is also electrically conductive; (c) lower ends of the contact strips (71, 72) of contact (S2) are fixed and electrically connected to the control circuit on the PCB for the connection;(d) the contact points (S2a, S2b) are actuated by a projection (75) on the lower end of the main lever (40);(e) wherein during switch-off, before end of the stroke of main lever (40), the projection (75) touches and pushes the contact strip (71) to close contact S2, and during switchon, the contact strips (72, 71) are shown moving to open contact S2, and coming to rest against their respective stoppers (73,74);(f) wherein the location of the arrangement for S2 is on one side of the main bracket (width-wise) for a one-way switch, and on the other side ( i.e. both sides) of the main bracket for a two-way switch.

7. The electric switch (100) of claim 2, further comprising a mechanism to operate contact S2, wherein for NO type contact,(a) a contact point (S2a) is supported by a projection (78) on the main bracket (50) at the lower portion on one side of the vertical centre line wherein contact point (S2a) is fixed and internally connected to the PCB;(b) a cantilever spring strip (79) carrying contact point (S2b) is positioned such that its lower end is connected to the PCB for electrical connection, wherein the cantilever spring strip is made of electrically conductive spring material;(c) the portion of the cantilever spring strip (79) above contact point S2b is positioned to interact with a projection (75) on the lower portion of the main lever (40);(d) the contact point (S2b) is actuated by the projection (75) on the lower end of the main lever (40);(e) wherein during switch-off, just before end of stroke of main lever (40), the projection (75) pushes the cantilever spring strip (79) and holds there to maintain contact S2 in open position, and during switch-on, when the main lever (40) starts rotating clockwise, the cantilever spring strip is released allowing contact point S2b to make contact with contact point S2a to close the contact, due to the spring force; and (f) wherein the location of the arrangement for S2 is on one side of the main bracket (width-wise) for a one-way switch, and on both sides of the main bracket for a two-way switch.

8. The electric switch (100) of claim 1,(a) wherein the switch is configured to fit within a standard wall-mounted electrical box; and(b) a visual indicator system comprising one or more LEDs (103) electrically connected to the control circuit, configured to display different states including power status, switch position, and status of solid-state switching element , with specific indication patterns defined by the control circuit logic based on the current operational state of the switch.

9. The electric switch (100) of claim 5, wherein the speed deceleration mechanism (500) comprises a top plate (90) placed on two rocking plates (96, 96’)_held in place by springs (99, 99’) that control the movement speed of the main levers (30, 40) to ensure:(i) a first-time delay of at least 10 milliseconds between the activating of the second contact (S2) and the closing of the third moving contact (S3) or opening of SI’ during the transition from the OFF position to the ON position in case of one-way switch or vice versa in case of two-way switch; and(ii) a second time delay of at least 10 milliseconds between the activating of the second contact (S2) and the opening of the first contact (SI) or closing S3’ during the transition from the ON position to the OFF position in case of one-way switch or vice versa in case of two-way switch.

10. The electric switch (100) of claim 1, wherein:(a) the switch is configured to function as a two-way switch;(b) the switch further comprises additional contacts SI', S2', and S3' arranged symmetrically to contacts SI, S2, and S3 respectively;(c) the main bracket is designed with a common layout for fixed contacts SI a, Sl'a, S2, S2', S3a and S3 ’a;(d) contact S2 is positioned on one side of the main bracket and contact S2' is positioned on the opposite side of the main bracket;(e) a cantilever leaf spring (64’) similar to the one carrying contact Sib is arranged to operate contact SI' with the opposite main lever, wherein the cantilever leaf spring is made common from single strip, wherein middle portion of the cantilever leaf spring is clamped at the top by the clamp 52 carrying contact Sib on one side and contacts l’b on other side;(f) the main lever (40) carries a parallel contact point S3b that comes in contact with a fixed contact point S3a rigidly attached to the main bracket (50) in case of one-way switch and similarly main lever 30 also carries a parallel contact point S3’b in case of two-way switch and comes in contact with a fixed contact point S3 ’a on the main bracket;(g) the fixed contact points S3a and S3’a is internally connected to an external terminal for connecting to a load and also to appropriate end of the solid-state switching element, for one way and two way switch configuration respectively; and(h) wherein the Speed Deceleration mechanism (500) is designed common and works with One Way Switch as well as Two Way Switch.

11. The electric switch (100) of claim 2, wherein:(a) the torsion spring (66) is replaced by a cantilever beam spring (63) made of flat strip spring material;(b) the cantilever beam spring (63) is combined in one piece for both levers (30, 40); (c) the middle portion of the cantilever beam spring is clamped by the clamp (52) at the top centre (51) of the main bracket (50) along with the flexible connection (60, 64); (d) the free - other ends of the cantilever beam spring are rigidly attached to the main levers (30, 40) at points KL and OP respectively;(e) when spring (66) is used, the projections (55, 55’) on the side of the main bracket are required for supporting the pivot pins (37, 37’, 47, 47’) and torsion spring seats (38, 38’, 48, 48’) and projections (39, 39’, 49, 49’) for resting spring leg 68a, 68b, on both sides of main leavers (30, 40); and(f) when the cantilever beam spring (63) is used the need for pivot points A and B, their associated pivot pins (37, 37’ 47, 47’), projections (55, 55’), as well as the torsion spring seats (38, 38’, 48, 48’), projections (39, 39’, 49, 49’) for resting spring leg 68a, 68b on both sides of main leavers (30, 40) are eliminated and the associated wear & tear at pivot pins are also eliminated.

12. The electric switch of claim 5, wherein the speed deceleration mechanism (500) ensures a minimum delay of 10 milliseconds for one way or two-way switches, wherein the speed deceleration mechanism comprises:(a) two rocking plates (96, 96') pivotally mounted on fixed grooves points (57, 57') located on a bottom portion of the mai" ^™^et (50);(b) a top plate (90) supported on the two rocking plates (96, 96') via V-slots (98, 98') in the top plate;(c) two springs (99, 99') with its lower ends attached to fixed points (59, 59') on the main bracket (50) and upper ends hooked into grooves (97, 97') on the top comers of the top plate (90), wherein two springs (99, 99') are attached by a pin through the eye type hook on both side of the spring;(d) a step (91) on the top side of the top plate (90) with two faces (95, 95');(e) a projected portion (45) on the main lever (40) with a face (46) configured to contact the faces (95) of the top plate (90) and projected portion 35 on main lever 30 with a face 36 to contact the face (95’) of the top plate 90 during operation;(f) a stopper (58) projecting from the main bracket (50) with stopper faces (94, 94') to limit the movement of the top plate (90);(g) a step (92) on the lower side of the top plate (90) with step faces (93’), that rest on the stopper faces (94’), when the top is shifted from right to left and step face 93 that rest on stopper face 94 when the top plate is shifted from left to right; and(h) wherein the speed deceleration mechanism is configured to:(i) allow horizontal reciprocation of the top plate (90) between two extreme stable positions;(ii) require a force to shift or reciprocate the top plate (90) as the springs (99, 99') gets stretched, thereby exerting an opposing torque on the main lever 40 while shifting from right to left and on main lever 30 while shifting from left to right;(iii) gradually increase the spring force as the rocking plates (96, 96') approach a vertical position, and then gradually decrease the force; (iv) release the main lever (40) - release face 46 from face 95 ( or release main lever 30 - release face 36 from face 95’) from contact with the top plate (90) before the end of its stroke, ensuring full spring (66) or (63) force is applied when contact S3 or S3’ gets closed;(v) lower the initial velocity of the main lever (40) moving outwards (rotating clockwise) during switch-ON, thereby delaying the closing of contact S3 due to the opposing torque; and(vi) lower the initial velocity of the main lever 30 moving out ward ( rotating anticlockwise) during switch-OFF, thereby delaying the opening of contact SI due to the opposing torque, whereby the speed deceleration mechanism (500) ensures the required minimum delay of 10 milliseconds between contact operations during both switch-ON and switch-OFF transitions, wherein the speed deceleration mechanism (500) works in isolation of the Main levers (30, 40), and wherein the top plate 90 does not come in the way of main lever projections while manually operating, lever 30 at switch ON, and lever 40 at switch OFF, top plate 90 comes in contact only when leaver 40 is released from the latch and starts rotating clockwise at switch ON and similarly when lever 30 is released and it starts rotating anticlockwise at switch OFF.

Images