663 results about "DIAC" patented technology

The invention discloses an LED drive circuit with dimming function and a lamp. The LED drive circuit comprises a TRIAC dimmer; the TRIAC dimmer receives an alternating-current input voltage and generates a cut phase voltage signal; the cut phase voltage signal is rectified by a rectifying module and then coupled to a dimming signal generator; and a power factor correcting controller receives an output signal of the dimming signal generator, reflects a feedback signal of LED brightness, and outputs a switching control signal to control the on and off of a switching tube so as to drive an LED. The dimming of the LED is implemented by adjusting a conduction angle of the TRIAC dimmer.

The invention discloses an LED (Light Emitting Diode) drive circuit with a dimming function and a lamp. The drive circuit comprises a triode AC (Alternating Current) semiconductor switch (TRIAC) light modulator which receives alternating current input voltage, and generates a phase-cut voltage signal which is rectified through a rectifier module to be coupled to a dimming signal generator; a power factor collection controller receives the output signal of the dimming signal generator and a feedback signal reflecting the brightness of an LED; and an output switch control signal controls the on and off of a switch tube so as to realize the drive of the LED. Through adjusting the conduction angle of the TRIAC light modulator, the dimming of the LED is realized.

Switch devices, such as Silicon Controlled Rectifier (SCR), DIAC, or TRIAC, on a semiconductor body are disclosed. P / N junctions can be built on a semiconductor body, such as polysilicon or active region body on an insulated substrate, with a first implant in one end and a second implant in the other end. The first and second implant regions are separated with a space. A silicide block layer can cover the space and overlap into both implant regions to construct P / N junctions in the interface.

A quasi-phase active preload circuit to be coupled at the output of a non-isolated LED driver converter having a pre-stage phase-angle control dimmer circuit, such as a commonly used leading-edge control Triac dimmer, is disclosed. The quasi-phase active preload circuit may include a preload resistor coupled to a current-controlled current source configured to draw a sinking current through the preload resistor based on a peak detect signal. The peak detect signal may be, in one example, representative of a leading-edge peak voltage of an output of the Triac dimmer circuit, which may be representative of a conduction angle of the Triac dimmer circuit. During normal operating conditions, no sinking current is drawn through the preload resistor. During low dimming conditions, a sinking current that is responsive to the peak detect signal is drawn through the preload resistor. During deep dimming or when used with a leaky Triac dimmer, a maximum sinking current may be drawn through the preload resistor by the current-controlled current source.

The invention relates to a voltage-stabilization electricity-saving device, and particularly relates to an undisturbed switching mechanism of the voltage-stabilization electricity-saving device. The undisturbed switching mechanism comprises a power source, a compensation transformer connected with the power source and a voltage-regulating transformer connected in series between the power source and the compensation transformer. The undisturbed switching mechanism further comprises a load connected in parallel at the two ends of the compensation transformer, and a bidirectional thyristor mechanism connected in series with the compensation transformer. The undisturbed switching mechanism is characterized in that the undisturbed switching mechanism further comprises a series circuit formed by a resistor and a bidirectional thyristor, wherein the series circuit is connected in parallel to the secondary coil of the compensation transformer. Compared with the prior art, the undisturbed switching mechanism in the invention solves the problem of strong impact generated during thyristor switching, and obvious noise cannot be generated during switching, so that the stability of the system is greatly improved, the service life of the thyristor is prolonged, and the capacity of the intelligent voltage-stabilization electricity-saving device can be greatly increased when the thyristors with same capacity and withstand voltage level are adopted.

A two terminal arc suppressor for protecting switch, relay or contactor contacts and the like comprises a two terminal module adapted to be attached in parallel with the contacts to be protected and including a circuit for deriving an operating voltage upon the transitioning of the switch, relay or contactor contacts from a closed to an open disposition, the power being rectified and the resulting DC signal used to trigger a power triac switch via an optoisolator circuit whereby arc suppression pulses are generated for short predetermined intervals only at a transition of the mechanical switch, relay or contactor contacts from an closed to an open transition and, again, at an open to a close transition during contact bounce conditions.

A light-adjusting and current-limiting control circuit for a lamp includes a sampling circuit formed of a manganese-copper line or a current transformer, a power circuit provided with resistors, capacitors, diodes, a Varistor and a zener diode, a signal adjusting circuit composed of diodes, resistors, a varistor, triacs and capacitors, and a control output circuit having a thyristor, diodes, a relay and an LED. The control output circuit can be replaced with a light-adjusting input circuit, a chip processor control circuit, a zero-crossing detection circuit and a two-way silicon controlled rectifier control output circuit 5. Thus, the invention has a low cost, a small size and an excellent precision, compared to conventional ones.

Disclosed herein is a dimmer switch having a broad range of control with a relatively simple circuit having a number of safety features. The circuit employs a triac and diac to selectively conduct an AC power wave. A variable phase shift network having an improved range of control governs the firing angle of the diac. The variable phase shift network includes a first and second series R-C circuits coupled by a bridge resistor.

A motor starter for use with a motor (20) having a main winding (M) and a start winding (S). The starter has a PTC thermistor (30) connected in series with the start winding (S). A triac (40) is connected between PTC thermistor (30) and a power source line. A control circuit (50) is connected to the power source line for providing a voltage for a gate terminal (G) of triac (40) and an overload relay (60) is connected between the power source (10) and the motor (20). The control circuit (50) preferably includes a current detecting circuit (52) for detecting the inrush current and a voltage generating circuit (54) for generating the voltage in response to the detected inrush current. At the startup of motor (20) the control circuit (50) allows triac (40) to turn on by providing the gate terminal (G) with the voltage based on the inrush current. According to this invention, the power consumption of the start winding S after the startup of the motor (20) can be almost zero thus providing low power consumption. In another embodiment not employing a PTC thermistor, a current detecting circuit and a voltage generating circuit are used to control the on and off states of a first triac (90) which in turn controls the on and off states of a second triac (92) connected in series with the start winding.

An electrical surge protection device (12) confers protection to an output node (13) from electrical surges on a data or power line (10) incident on an input node (11). A transistorised surge protection device (18) is located in a current path between the input node (11) and the output node (13) and is configured to assume an isolating state in response to an over-current therethrough. A voltage-triggered protective circuit comprising a diac (16) in series with a bi-directional zener diode (14) is connected between the output side of the transistorised surge protection device (18) and a surge sinking node (15). The voltage-triggered circuit assumes a low-impedance state in response to an electrical surge at output terminal 13. Consequently a surge current is passed through zener diode (14) and surge diac (16) to the surge sinking node. In response to the surge current the transistorised surge protection device (18) assumes a high impedance configuration thereby isolating output node (13) from input node (11). Since neither the zener diode and diac combination, nor the transistorised surge protection device (18) are subject to sustained surge associated currents, embodiments of the invention can be compactly packaged.

A tunable voltage isolation ground to ground ESD clamp is provided. The clamp includes a dual-direction silicon controlled rectifier (SCR) and trigger elements. The SCR is coupled between first and second grounds. The trigger elements are also coupled between the first and second grounds. Moreover, the trigger elements are configured to provide a trigger current to the dual-direction silicon controlled rectifier when a desired voltage between the first and second grounds is reached.

An HVAC system has at least one variable speed controller for an AC induction motor, especially of the Permanent Split Capacitor (PSC) type. The variable speed controller provides switched power via a modulating triac to the main coils of the motor and constant power via an on / off triac to the auxiliary coils during operation. A large value capacitor is placed in line with the auxiliary coils to reduce power consumption and current draw over that of known systems. Power to the motor can be turned off to provide for motor speed sensing through monitoring the frequency of a generated voltage when the power is turned off. Frequency-based motor speed sensing is accomplished by shutting off all current to the motor and measuring zero crossings on the generated voltage of the decaying magnetic field. The controller can be easily retrofitted onto existing motors. An optional controller bypass is provided to run the motor at rated speed in case of controller failure.

An electromagnetic interference (EMI) filter is provided to attenuate potentially damaging high frequency electromagnetic interference from interfering with the operation of a hermetically sealed implantable medical device. In one embodiment, the EMI filter is joined to a bypass unit that is configured to provide an energy path for the delivery of an energy pulse. The bypass unit, in one embodiment, may include a non-linear device in parallel with an impedance component. The non-linear device can be a DIAC, a MOSFET, or any other non-linear semiconductor array. The EMI filter may be located within the header assembly, the feedthrough assembly, or located proximate to a pulse generator along the energy delivery path.

The present invention discloses an asymmetric bidirectional silicon-controlled rectifier, which comprises: a second conduction type substrate; a first conduction type undoped epitaxial layer formed on the substrate; a first well and a second well both formed inside the undoped epitaxial layer and separated by a portion of the undoped epitaxial layer; a first buried layer formed in a junction between the first well and the substrate; a second buried layer formed in a junction between the second well and the substrate; a first and a second semiconductor area with opposite conduction type both formed inside the first well; a third and a fourth semiconductor area with opposite conduction type both formed inside the second well, wherein the first and second semiconductor areas are connected to the anode of the silicon-controlled rectifier, and the third and fourth semiconductor areas are connected to the cathode of the silicon-controlled rectifier.

The invention discloses a PNPNP type triac which comprises a P type substrate, wherein an N type buried layer is arranged in the P type substrate, a P well is injected on the N type buried layer, an annular N well in the junction depth which is the same with that of the P well is injected between the side surface of the P well and the P type substrate, a first N type drift region and a second N type drift region are injected in the P well, a first P+ injection region and a first N+ injection region are arranged in the first N type drift region, and a second P+ injection region and a second N+ injection region are arranged in the second N type drift region, wherein the first P+ injection region and the second P+ injection region are positioned on the inner side, and oxidation and isolation layers are covered on the P type substrate, the N well and the P well. The PNPNP type triac structure can realize the compatibility of the process with the commonly used BCD process in the industry; as the PNPNP type triac structure has higher and symmetric forward and reverse breakdown voltage, the PNPNP type triac is more applicable to ESD protection application of a plurality of mixed voltage interface circuits or among different power domains.

The invention discloses a deicing robot of high-voltage transmission lines. The deicing robot is composed of a tackle and a control system. A controller is arranged in the tackle. The tackle is composed of a tackle body, a suspension arm, pulleys, a deicing mechanism, a power system, a storage battery and a driving mechanism. The deicing mechanism is composed of a rack, deicing wheels, a deicing driving mechanism and a lifting driving mechanism. The controller is composed of an air pressure sensor, an air temperature sensor, a humidity sensor, a wind speed sensor, a rainfall sensor, a charging and discharging controller, a GPS module, a driving module, a bidirectional thyristor module, a communication module, a data processing module and a data storing module. According to the deicing robot, whole-process monitoring can be performed on the temperature, the humidity and the icing conditions of the high-voltage transmission lines, the acquisition of data information is accurate and complete, deicing can be automatically carried out, and hot melting and physical cutting can be synchronously performed in the deicing process. Compared with traditional deicing equipment, the deicing robot is high in deicing efficiency and low in deicing vibration degree, and negative influences on the high-voltage transmission lines in the traditional deicing process are effectively reduced.

A triac controller includes a triac driver that provides a triac control signal suitable for connection to a gate terminal of a triac, such that, when in a power-on condition, the control signal carries at least a first firing pulse during each half period of the alternating current power supply. A soft start subcircuit and a zero crossing detector directs the triac driver to produce the first firing pulse at a first firing pulse delay time after the zero crossing time. During a soft start operation the first firing pulse delay time varies monotonically with each successive half period from an initial delay time to a final delay time. An auto-retriggering subcircuit causes the triac driver to produce a second firing pulse at a predetermined retriggering delay time from an end of the first firing pulse if the triac is not in an on conduction state after the end of the first firing pulse during a same half period. The auto-retriggering subcircuit causes the triac driver to produce retriggering firing pulses periodically for so long as the triac is not in the on conduction state during the same half period; however, it is inhibited from causing the triac driver to produce retriggering firing pulses during a predetermined retriggering mask period at an end of the same half period. The soft start subcircuit includes a table specifying a plurality of predetermined first firing pulse delay values. A set signal is used to determine an index into the table. The plurality of predetermined first firing delay values is monotonically organized with respect to the index into the table, and a programmable rate variable determines a rate of change of the first firing delay values during a soft start operation.

A diode for alternating current (DIAC) electrostatic discharge (ESD) protection circuit is formed in a silicon germanium (SiGe) hetrojunction bipolar transistor (HBT) process that utilizes a very thin collector region. ESD protection for a pair of to-be-protected pads is provided by utilizing the base structures and the emitter structures of the SiGe transistors.

The invention discloses a bidirectional triode thyristor for electrostatic discharge protection of a radio frequency integrated circuit, comprising a P-type substrate on which a P trap, a first N trap and a second N trap are arranged, wherein the first N trap and the second N trap are arranged at two sides of the P trap; a first N<+> injection region, a first P<+> injection region and a third N<+> injection region which are isolated by a shallow ditch are sequentially arranged above the first N trap from the outside to the inside, wherein the third N<+> injection region crosses the junction of the first N trap and the P trap; a second N<+> injection region, a second P<+> injection region and a fourth N<+> injection region which are isolated by a shallow ditch are sequentially arranged above the second N trap from the outside to the inside, wherein the fourth N<+> injection region crosses the junction of the second N trap and the P trap; and the surface of the P trap arranged between the third N<+> injection region and the fourth N<+> injection region is covered with gate oxide and polysilicon gates which are stacked in sequence from bottom to top. By utilizing the source-drain punchthrough of an NMOS (N-Channel Metal Oxide Semiconductor) to assist in triggering, the bidirectional triode thyristor provided by the invention has small starting voltage and parasitic capacitance and strong robustness and can provide bidirectional ESD (Electro-Static Discharge) protection.

The invention relates to a method and a device for fluorescent lamp two-wire system dimming control. A user end microprocessor receives a user request signal to ensure that the change in a circuit is impeded, thereby a large chamfer voltage waveform signal is formed on an alternating wire within a period of time and forms a dimming control signal after being subjected to waveform conversion of an electronic ballast and signal detection processing. The device is formed by connecting a user control end and an electronic ballast end through alternating current wires. The user control end comprises a dimming control signal input circuit, an impedance switching circuit and a bidirectional control silicon circuit; and the electronic ballast end comprises a rectifying circuit, a power factor correction circuit and an inverter circuit which are sequentially connected, and a waveform conversion circuit, a waveform recognition and digital / analogue conversion circuit and a lower-pass filter circuit. The invention forms the large chamfer voltage waveform signal only in short time for regulation and control operation and only maintains a smaller initial chamfer in other time, therefore, the power factor of the ballast can be maintained above 0.95 and the total current harmonic distortion can be improved to be less than 20 percent.

The invention discloses a self-adaptive PID (proportion integration differentiation) temperature control method, which comprises the following steps of: step 1, collecting a temperature in real time; step 2, calculating a heating speed in real time; step 3, adjusting a PID parameter according to the real-time heating speed; step 4, carrying out PID arithmetic; and step 5, converting the result of the PID arithmetic into continuous control on a time quantum, and directly controlling the switching on and the switching off of the working current of a heater strip by using a bidirectional silicon controlled rectifier. The technical effects of the self-adaptive PID temperature control method lie in that the heating speed is calculated in a heating process; a control parameter is adjusted dynamically, so that the heating process is more stable; the algorithm is subjected to multiple tests on a plurality of different instruments at different ambient temperatures; results show that an appointed temperature can be stably achieved in a heating way; an overshoot phenomenon cannot appear in the heating process; and the precision meets a system requirement.

An apparatus including an electrostatic discharge (ESD) protection structure with a diac in which substancially similar ESD protection is provided for both positive and negative ESD voltages appearing at the circuit electrode sought to be protected.

A protected capacitor system / method implementing enhanced transient over-voltage suppression is disclosed. The system / method incorporates one or more surge suppression devices (SSDs) proximally located and in parallel with a capacitor structure to produce an overall protected capacitor structure having enhanced reliability and simultaneous ability to resist transient overvoltage conditions. The SSDs are formed from series combinations of transient voltage surge suppressors (TVSs) (metal oxide varistor (MOV), diode for alternating current (DIAC), and / or silicon diode for alternating current (SIDAC)) and corresponding shunt diode rectifiers (SDRs) and placed in parallel across a capacitor structure to locally suppress voltage transients across the capacitor structure in excess of the voltage rating of the capacitor structure. The parallel shunting TVB / SDR pairs may be integrated into a printed circuit board (PCB) assembly that is externally attached to the capacitor structure or encapsulated in an enclosure incorporating the capacitor structure.

The invention relates to the field of home appliances and discloses a detection circuit for a washing machine door cover, which comprises a microswitch and a washing machine main control unit, wherein the microswitch is switched on and off by using the door cover, the washing machine main control unit is used for detecting the on and off states of the microswitch and respectively connected with two ends of the microswitch through ports A and B, the washing machine main control unit sends a pulse signal through the port A and receives the pulse signal through the port B to form an annular circuit. The scheme discards the mode that the washing machine main control unit in the prior art passively receives an opening / closing signal of the door cover, an active detection mode is adopted, and a bidirectional triode thyristor acts to control the operating state of the motor, which realizes that the opening / closing information of the door cover is detected in real time and avoids the problem that the opening / closing information of the door cover can not be rightly received by the washing machine main control unit due to the failure of a peripheral circuit in the prior art.

The present invention relates to a contactless enegy-saving starter which is characterized in that: the device includes a PTC thermosensitive resistor Rp, a three-end bidirectional controllable silicon T, a photocoupler U, a sensor L and a rectifying bridge D. In the present invention, a photocoupler U is used to trigger the three-end bidirectional controllable silicon T, thus, the situation that the controllable silicon is not conducted and stopped absolutely because of the un-synchrony of the phase of the triggered control signal and the started loop is avoided, and the reliability is improved greatly. Thus, not only the successful stating of the electric motor is assured, and the started loop is broke absolutely because the bidirectional controllable silicon is stopped absolutely after the starting is achieved. The energy consumption by the thermosensitive resistor Rp is eliminated because there is no current flowing through the PTC thermosensitive resistor Rp.

A tunable voltage isolation ground to ground ESD clamp is provided. The clamp includes a dual-direction silicon controlled rectifier (SCR) and trigger elements. The SCR is coupled between first and second grounds. The trigger elements are also coupled between the first and second grounds. Moreover, the trigger elements are configured to provide a trigger current to the dual-direction silicon controlled rectifier when a desired voltage between the first and second grounds is reached.

The invention provides a control circuit and method for a discharge circuit, a chip and a driving system and method. The control method comprises the steps of controlling the delay conduction time ofthe discharge circuit in the next period according to the obtained current period light modulator conduction time, the expected conduction time and the preset time different threshold, and generatingan enable signal used for dynamically adjusting the discharge circuit according to the delay conduction time. By controlling the enable signal of the discharge circuit, a bidirectional silicon controlled rectifier of the light modulator is enabled to trigger the conduction by being delayed to the expected conduction time, so that the power consumption of the discharge circuit is reduced, and the reliability of a driving system of the light modulator is improved.

An electromechanical / solid-state AC relay has an electromechanical winding coil that moves an armature to force mechanical contacts to open or close. Electrical arcing across the mechanical contacts that occur as the contacts are opening or closing can damage and severely reduce the lifetime of the relay. Contact arcing is prevented by pulsing a triac on for a short period of time just before and after the mechanical contacts make or break contact. The triac limits the voltage difference across the mechanical contacts to less than one volt to prevent arcing. The triac is turned off after the mechanical contacts finish moving, reducing the heating and average power through the triac. A zero-sampling circuit that detects when the AC input voltage switches across 0 volts and activates a control integrated circuit to switch on the triac during zero-crossings to minimize power surges.