A protection circuit and lamp for preventing dim light and outputting inductive electricity

Abstract

The present invention proposes a protection circuit and a lamp for preventing dimming of lamps and outputting induction electricity. The protection circuit is arranged into a module, the module is connected between the live wire and the neutral wire of the LED lamp, and includes a voltage-stabilizing diode, a capacitor, a comparator, a diode, a triode and a relay connected to the input power supply; the cathode of the voltage-stabilizing diode is connected to the input power supply, the cathode of the voltage-stabilizing diode is connected to the same-direction input end of the comparator, the anode of the voltage-stabilizing diode is connected to the reverse input end of the comparator, the capacitor is arranged in parallel with the voltage-stabilizing diode, the output end of the comparator is connected to a sixth resistor, the sixth resistor is arranged in parallel with the diode, the positive electrode of the diode is connected to the base of the triode, the collector of the triode is connected to the input power supply, the emitter of the triode is connected to the electromagnet of the relay to form a loop, and the contacts of the relay are arranged in series with a seventh resistor. The present invention shields invalid outputs to ensure the safety of electrical equipment and human body.

Description

Technical Field

[0001] The invention relates to the technical field of protection circuits for preventing lamps from dimming and outputting induced electricity, and in particular to a protection circuit for preventing lamps from dimming and outputting induced electricity. Background Art

[0002] Conventional LED driver power supplies only turn off the neutral line of the electrical circuit, causing the live wire to be energized and produce a basic potential difference with the circuit, making the power supply in a semi-working state. Since conventional LED circuits use a non-isolated design, the output LED has a weaker voltage and current.

[0003] In the prior art, when the output voltage and current are detected (the output current is less than 50mA or the output voltage is less than 36V), the + and - poles of the output are connected through the switch tube (MOS) to prevent the output part from being charged and protect the output end. When the primary switch is closed, the output end comparator detects that the output voltage is greater than 5V and the output current is greater than 50mA (which can be set), and the output MOS will be turned off, so that the output works normally. This circuit only turns off the neutral line circuit, resulting in the metal casing being charged in the shutdown state. Summary of the invention

[0004] The purpose of the present invention is to address the above-mentioned problems and provide a protection circuit and a lamp that can prevent dimming of the lamp and output induced electricity, shield invalid output, and ensure the safety of electrical equipment and human body.

[0005] The present invention proposes a protection circuit for preventing a lamp from dimming and outputting induced electricity, and a lamp. The protection circuit is arranged as a module, the module is connected between the live wire and the neutral wire of the LED lamp, the module comprises a voltage-stabilizing diode, a capacitor, a comparator, a diode, a transistor and a relay connected to an input power supply; the cathode of the voltage-stabilizing diode is connected to the input power supply, the cathode of the voltage-stabilizing diode is connected to the same-direction input end of the comparator, the anode of the voltage-stabilizing diode is connected to the reverse input end of the comparator, the capacitor is arranged in parallel with the voltage-stabilizing diode, the output end of the comparator is connected to a sixth resistor, the sixth resistor is arranged in parallel with the diode, the positive electrode of the diode is connected to the base of the transistor, the collector of the transistor is connected to the input power supply, the emitter of the transistor is connected to the electromagnet of the relay to form a loop, and the contacts of the relay are arranged in series with a seventh resistor.

[0006] Preferably, a reference terminal of the comparator is connected to the input power supply via a third resistor, and the other reference terminal is grounded.

[0007] Preferably, a first resistor is connected between the input power supply and the cathode of the voltage stabilizing diode.

[0008] Preferably, a second resistor is connected between the anode of the capacitor and the same-direction input terminal of the comparator.

[0009] Preferably, a fifth resistor is connected between the collector of the transistor and the input power supply.

[0010] Preferably, a fourth resistor is connected between the output end of the comparator and the diode.

[0011] Preferably, the voltage zener diode limits the power supply voltage to within the breakdown voltage range of the voltage zener diode through energy storage and triggering of the capacitor, thereby protecting the comparator from being damaged by excessive voltage.

[0012] A lamp is also provided, comprising the above-mentioned lamp dimming protection circuit and the protection circuit for outputting induction electricity.

[0013] Beneficial effects of the present invention:

[0014] The invention discloses a protection circuit and a lamp for preventing dim light and outputting induced electricity. The input power supply uses a comparator to detect the input power supply voltage. If the input power supply is turned off, the comparator (IC output is powered off), and the Q1 output is turned off, causing the relay coil to change from being attracted to being disconnected (the relay is powered off in a normally closed state by default). Due to the normally closed state of the relay, the front end of the output LED is closed, resulting in the output induced voltage being 0V. The output strobe or induced voltage becomes a safe output due to the short circuit closure of the front end.

[0015] After the input end is powered on normally, since the voltage difference of the voltage stabilizing diode is less than the input voltage difference, the detection delay is performed through the capacitor charging. This causes the comparator to flip the output trigger voltage, and through the amplification of the transistor, the relay is attracted, changing the line short-circuit state to +, - open circuit state, and the back-end current and voltage are output normally. At the same time, in order to ensure that the current and voltage are too high at the moment of power-on, a seventh resistor is connected in series with the relay contact to ensure an incomplete short-circuit state from + to -, ensuring the reliability of the line;

[0016] The protection circuit is designed as a module and applied to LED lighting and home appliance power control. It is convenient to output a certain induced voltage when the power neutral line is disconnected to ensure user safety. The first resistor, the second resistor and the voltage regulator diode are mainly used to detect whether the input VDD power supply voltage is available. The functions of the first resistor and the second resistor are mainly used for input voltage detection and current limiting. The voltage regulator diode mainly plays the role of input voltage stabilization. When the input voltage is greater than the voltage of the voltage regulator diode, the voltage regulator diode limits the input power supply voltage within the range of the voltage regulator diode through the energy storage and triggering of the capacitor C, protecting the comparator from damage due to excessive voltage. The capacitor mainly plays the role of energy storage triggering. After the input power supply voltage is stored by the capacitor, the trigger comparator drives the base of the amplifying transistor through the fourth resistor and the sixth resistor to trigger the relay coil to disconnect the output part of the short-circuit state. The third resistor is used to provide power supply and current limiting functions to the comparator. The seventh resistor and the relay are connected in series to form a low-impedance short-circuit (power-off state) loop to prevent the current of the single-point grounding loop of the relay from being too large during transient triggering, causing current impact on the input end, and play a current limiting protection role. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a circuit schematic diagram in one embodiment of the present invention;

[0018] Among them, ZD1-voltage regulator diode, U1-comparator, D1-diode, Q1-transistor, J1-relay, C1-capacitor, R1-first resistor, R2-second resistor, R3-third resistor, R4-fourth resistor, R5-fifth resistor, R6-sixth resistor, R7-seventh resistor. DETAILED DESCRIPTION

[0019] refer to Figure 1The present invention proposes a protection circuit for preventing dim light of a lamp and outputting inductive electricity and a lamp. The protection circuit is configured as a module. The protection circuit is configured as a module. The module is connected between the live wire and the neutral wire of the LED lamp, and includes a voltage stabilizing diode ZD1, a capacitor C1, a comparator U1, a diode D1, a transistor Q1 and a relay J1 connected to an input power supply; the cathode of the voltage stabilizing diode ZD1 is connected to the input power supply, the cathode of the voltage stabilizing diode ZD1 is connected to the same-direction input terminal of the comparator U1, and the anode of the voltage stabilizing diode ZD1 is connected to the comparator U1. The inverting input terminal of the comparator U1 is connected to the inverting input terminal of the comparator U1, the capacitor C1 is arranged in parallel with the voltage stabilizing diode ZD1, the inverting input terminal of the comparator U1 is connected to the input power supply, the output terminal of the comparator U1 is connected to a sixth resistor R6, the sixth resistor R6 is arranged in parallel with the diode D1, the anode of the diode D1 is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to the input power supply, the emitter of the transistor Q1 is connected to the electromagnet of the relay J1 to form a loop, and the contacts of the relay J1 are serially connected with a seventh resistor R7.

[0020] In this embodiment, the input power supply uses a comparator U1 to detect the input power supply voltage. If the input power supply is turned off, the comparator U1 (IC output is powered off), the transistor Q1 output is turned off, causing the relay J1 coil to change from being attracted to being disconnected (the relay J1 is powered off in a normally closed state by default). Due to the normally closed state of the relay J1, the front end of the output LED is closed, resulting in the output induced voltage being 0V, and the output strobe or induced voltage becomes a safe output due to the short circuit closure of the front end;

[0021] After the input power is normally powered on, since the voltage difference of the voltage zener diode ZD1 is less than the input voltage difference, the capacitor C1 is charged to perform detection delay, causing the comparator U1 to flip the output trigger voltage, and through the amplification of the transistor Q1, the relay J1 is attracted, changing the line short-circuit state to the +, - open-circuit state, and the back-end current and voltage are output normally. At the same time, in order to ensure that the current and voltage are too high at the moment of power-on, the relay J1 contact is connected in series with a seventh resistor R7 to ensure an incomplete short-circuit state from + to -, ensuring the reliability of the line.

[0022] The third resistor R3 is used to provide power supply and current limiting function for the comparator U1. The seventh resistor R7 is connected in series with the relay J1 to form a low-impedance short-circuit (power-off state) loop to prevent excessive current in the single-point grounding loop of the relay J1 during transient triggering, causing current shock at the input end, thereby playing a current limiting protection role.

[0023] After the input power supply voltage is stored by capacitor C1, the trigger comparator U1 drives the base of the amplifier transistor Q1 through the sixth resistor R6 to trigger the relay J1 coil to disconnect the output part of the short-circuit state. The voltage regulator diode ZD1 mainly plays the role of input voltage stabilization. When the input voltage is greater than the voltage of the voltage regulator diode ZD1, the voltage regulator diode ZD1 limits the input power supply voltage within the range of the voltage regulator diode ZD1 through the energy storage and triggering of the capacitor C1C, protecting the comparator U1 from damage due to excessive voltage; the capacitor C1 mainly plays the role of energy storage triggering. The protection circuit is designed as a module and applied to LED lighting and home appliance power supply control. It is convenient to output a certain induced voltage under the condition that the power supply neutral line is disconnected, ensuring the safety of users. In one embodiment, the reference end of the comparator U1 is connected to the input power supply with a third resistor R3, and the other reference end is grounded.

[0024] In one embodiment, a first resistor R1 is connected between the input power supply and the cathode of the voltage zener diode ZD1. A second resistor R2 is connected between the anode of the capacitor C1 and the non-inverting input terminal of the comparator U1. The first resistor R1, the second resistor R2 and the voltage zener diode ZD1 are mainly used to detect whether the input VDD power supply voltage is available, and the functions of the first resistor R1 and the second resistor R2 are mainly used for input voltage detection and current limiting.

[0025] In one embodiment, a collector of the transistor Q1 and an input power source are connected via a fifth resistor R5 .

[0026] In one embodiment, a fourth resistor R4 is connected between the output end of the comparator U1 and the diode D1. After the input power supply voltage is stored in the capacitor C1, the comparator U1 is triggered to drive the base of the amplifier transistor Q1 through the fourth resistor R4 and the sixth resistor R6 to trigger the relay J1 coil to disconnect the output part and put it into a short-circuit state.

[0027] In one embodiment, the voltage zener diode ZD1 limits the power supply voltage to within the breakdown voltage range of the voltage zener diode ZD1 through energy storage and triggering of the capacitor C1, thereby protecting the comparator U1 from being damaged by excessive voltage.

[0028] A lamp is also provided, comprising the above-mentioned lamp dimming protection circuit and the protection circuit with induction electricity output.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0031] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] The above contents are further detailed descriptions of the present invention in combination with specific implementation methods, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention.

Claims

1. A protection circuit for preventing dimming of lamps and outputting inductive electricity, characterized in that: The protection circuit is configured as a module, which is connected between the live wire and the neutral wire of the LED lamp, and includes a voltage-stabilizing diode, a capacitor, a comparator, a diode, a transistor and a relay connected to the input power supply; the cathode of the voltage-stabilizing diode is connected to the input power supply, the cathode of the voltage-stabilizing diode is connected to the same-direction input terminal of the comparator, the anode of the voltage-stabilizing diode is connected to the reverse input terminal of the comparator, the capacitor is arranged in parallel with the voltage-stabilizing diode, the output terminal of the comparator is connected with a sixth resistor, the sixth resistor is arranged in parallel with the diode, the positive electrode of the diode is connected to the base of the transistor, the collector of the transistor is connected to the input power supply, the emitter of the transistor is connected to the electromagnet of the relay to form a loop, and the contacts of the relay are connected in series with a seventh resistor; when the input power supply is turned off, the relay is in a normally closed state, and due to the short-circuit closure of the front-end relay, the back end becomes a safe output; when the input power supply is normally energized, the relay is in a + and - open circuit state, and the back end current and voltage are output normally.

2. The protection circuit for preventing dim light and outputting inductive electricity of a lamp according to claim 1, characterized in that: The reference end of the comparator is connected to the input power supply via a third resistor, and the other reference end is grounded.

3. The protection circuit for preventing dim light and outputting inductive electricity of a lamp according to claim 1, characterized in that: The input power source and the cathode of the voltage stabilizing diode are connected via a first resistor.

4. The protection circuit for preventing dim light and outputting inductive electricity of a lamp according to claim 1, characterized in that: A second resistor is connected between the anode of the capacitor and the non-inverting input terminal of the comparator.

5. The protection circuit for preventing dim light and outputting inductive electricity of a lamp according to claim 1, characterized in that: The collector of the transistor and the input power supply are connected via a fifth resistor.

6. The protection circuit for preventing dim light and outputting inductive electricity of a lamp according to claim 1, characterized in that: A fourth resistor is connected between the output end of the comparator and the diode.

7. The protection circuit for preventing dim lighting and outputting inductive electricity of a lamp according to claim 1, characterized in that: The voltage stabilizing diode limits the power supply voltage within the breakdown voltage range of the voltage stabilizing diode through energy storage and triggering of the capacitor, thereby protecting the comparator from being damaged by excessive voltage.

8. A lamp, characterized in that: The invention comprises a protection circuit for preventing dim light of a lamp and outputting inductive electricity as described in any one of claims 1 to 7.

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