Phase conversion PWM circuit

Abstract

The utility model relates to a phase conversion PWM (Pulse Width Modulation) circuit, which comprises a phase conversion circuit, a rectification filter circuit connected with the phase conversion circuit, an auxiliary power supply, and a phase light modulator connected with the rectification filter circuit, wherein the phase light modulator is connected with an alternating current power supply; the rectifying and filtering circuit is used for converting alternating current into direct current; the phase conversion circuit is used for outputting a PWM signal. According to the utility model, the PWM signal is output through the rectification filter circuit and the phase conversion circuit, the loss is small, the whole circuit does not need to use a photoelectric coupler, the low-voltage PWM signal can be well output, the whole cost is low, and the reliability is high.

Description

TECHNICAL FIELD

[0001] The utility model relates to phase conversion circuit technical field, especially, a kind of phase conversion PWM circuit. BACKGROUND

[0002] The phase conversion circuit in current market, all adopt 4 diodes to carry out bridge rectification, directly sample from high voltage side, drive MOS tube switch, use photoelectric coupler, to convert into low voltage PWM signal, this kind of method needs to use high voltage MOS tube, rectifier bridge and photoelectric coupler, and the loss of overall circuit is larger, cause overall cost is higher, and reliability is not high. SUMMARY

[0003] The utility model discloses a kind of phase conversion PWM circuit, can solve or at least alleviate one or more of the above problems and other aspects problems in prior art.

[0004] In order to achieve the above purpose, the utility model provides a kind of phase conversion PWM circuit, wherein the phase conversion PWM circuit includes:

[0005] Phase conversion circuit, and the rectification filter circuit, auxiliary power supply connected with phase conversion circuit, and the phase dimmer connected with rectification filter circuit, the phase dimmer is connected with alternating current power supply;The rectification filter circuit is used to convert alternating current into direct current;The phase conversion circuit is used to output PWM signal.

[0006] In the phase conversion PWM circuit as described above, the phase conversion circuit includes MOS tube Q1, the drain of MOS tube Q1 outputs PWM signal;The source of MOS tube Q1 is grounded;The gate of MOS tube Q1 is connected with the one end of resistance R4, the positive electrode of stabilizing diode ZD2, the other end of resistance R4 is grounded, the negative electrode of stabilizing diode ZD2 is connected with the one end of resistance R2, the one end of resistance R3 and the negative electrode of stabilizing diode ZD1, the other end of resistance R2 is connected with the one end of resistance R1, the other end of resistance R1 is connected with rectification filter circuit and voltage input terminal Vin, the other end of resistance R3 and the positive electrode of stabilizing diode ZD1 are grounded.

[0007] In the phase conversion PWM circuit as described above, the rectification filter circuit includes diode D1 and diode D2, the positive electrode of diode D1 is connected with alternating current input terminal AC_L, the negative electrode of diode D1 is connected with the other end of resistance R1;The positive electrode of diode D2 is connected with alternating current input terminal AC_N, the negative electrode of diode D2 is connected with the other end of resistance R1, alternating current input terminal AC_L and alternating current input terminal AC_N are connected with phase dimmer.

[0008] In the phase conversion PWM circuit described above, the auxiliary power supply is a 5V DC voltage, which is connected to one end of resistor R5, and the other end of resistor R5 is connected to the drain of MOSFET Q1.

[0009] Compared with the prior art, the beneficial effects of this utility model are:

[0010] The phase conversion PWM circuit of this invention uses two ordinary rectifier diodes and an ultra-low voltage MOSFET, resulting in low losses. The entire circuit does not require an optocoupler to effectively output low-voltage PWM signals, resulting in low overall cost and high reliability. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the overall structure of the phase conversion PWM circuit of this utility model.

[0012] Figure 2 This is a schematic diagram of the phase conversion PWM circuit of this utility model.

[0013] In the diagram: 1. AC power supply; 2. Phase dimmer; 3. Rectifier and filter circuit; 4. Phase conversion circuit; 5. Auxiliary power supply. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0015] It should be noted that in the description of this utility model, the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. The terms "first," "second," and similar words used in the description of this utility model do not indicate any order, quantity, or importance, but are only used to distinguish different components, and therefore should not be construed as limiting this utility model.

[0016] Furthermore, it should be understood that, for ease of description, the dimensions of the individual components shown in the accompanying drawings are not drawn to actual scale; for example, the thickness or width of some layers may be exaggerated relative to other layers.

[0017] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined or described in one figure, it will not need to be discussed or described in detail in the description of the subsequent figures.

[0018] Figure 1 This is an overall structural diagram of the phase-conversion PWM circuit of this utility model. The diagram shows the AC power supply 1, phase dimmer 2, rectifier and filter circuit 3, phase conversion circuit 4, and auxiliary power supply 5 of the phase-conversion PWM circuit.

[0019] like Figures 1-2 As shown, the rectifier and filter circuit and the auxiliary power supply are both connected to the phase conversion circuit, and the phase dimmer is connected to the rectifier and filter circuit and the AC power supply respectively.

[0020] Specifically, the rectifier and filter circuit is used to convert AC power to DC power; the phase conversion circuit is used to output PWM signals; and the AC power supply is used to provide AC power.

[0021] Furthermore, the phase conversion circuit includes a MOSFET Q1, with the drain of MOSFET Q1 outputting a PWM signal; the source of MOSFET Q1 is grounded; the gate of MOSFET Q1 is connected to one end of resistor R4 and the positive terminal of Zener diode ZD2, the other end of resistor R4 is grounded, the negative terminal of Zener diode ZD2 is connected to one end of resistor R2, one end of resistor R3 and the negative terminal of Zener diode ZD1, the other end of resistor R2 is connected to one end of resistor R1, the other end of resistor R1 is connected to the rectifier filter circuit and the voltage input terminal Vin, and the other end of resistor R3 and the positive terminal of Zener diode ZD1 are grounded.

[0022] Furthermore, the rectifier filter circuit includes diodes D1 and D2. The positive terminal of diode D1 is connected to the AC input terminal AC_L, and the negative terminal of diode D1 is connected to the other end of resistor R1. The positive terminal of diode D2 is connected to the AC input terminal AC_N, and the negative terminal of diode D2 is connected to the other end of resistor R1. The AC input terminals AC_L and AC input terminals AC_N are connected to the phase dimmer.

[0023] Furthermore, the auxiliary power supply is a 5V DC voltage, which is connected to one end of resistor R5, and the other end of resistor R5 is connected to the drain of MOSFET Q1.

[0024] Specifically, the phase dimmer is connected to AC input terminals AC-L and AC input terminals AC-N. The AC power is rectified by diodes D1 and D2 to convert it to DC power. Resistors R1, R2, and R3 sample the converted DC voltage at Vin point and perform voltage division. A Zener diode ZD1 (20V) is connected in parallel with resistor R3 for voltage clamping. The voltage across resistor R3 is processed into a PWM square wave close to 20V. The duty cycle of this PWM waveform changes according to the adjustment of the phase dimmer at the input terminals. A Zener diode ZD2 (7.5V) is then connected in series to convert the gate drive of MOSFET Q1 into a 12.5V PWM square wave. The gate of MOSFET Q1 receives the 12.5V PWM signal, controlling the on / off state of MOSFET Q1. Resistor R4 is a bleeder resistor used to discharge the charge between the drain and source of MOSFET Q1.

[0025] The drain of MOSFET Q1 receives a 5V DC auxiliary power supply voltage, which is converted into a 5V high and low level PWM signal through the current limiting resistor R5. The duty cycle of this PWM signal changes according to the adjustment of the phase dimmer at the input terminal.

[0026] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A phase-conversion PWM circuit characterized by comprising: The application relates to a phase conversion circuit (4), a rectification filter circuit (3) connected with the phase conversion circuit, an auxiliary power supply (5), and a phase dimmer (2) connected with the rectification filter circuit, wherein the phase dimmer is connected with an alternating current power supply (1); the rectification filter circuit is used for converting alternating current into direct current; and the phase conversion circuit is used for outputting a PWM signal.

2. A phase-conversion PWM circuit according to claim 1, characterized in that The phase conversion circuit (4) comprises a MOS tube Q1, the drain electrode of the MOS tube Q1 outputs a PWM signal, the source electrode of the MOS tube Q1 is grounded, and the gate electrode of the MOS tube Q1 is connected with one end of a resistor R4 and the anode of a voltage stabilizing diode ZD2, the other end of the resistor R4 is grounded, the cathode of the voltage stabilizing diode ZD2 is connected with one end of a resistor R2, one end of a resistor R3 and the cathode of a voltage stabilizing diode ZD1, the other end of the resistor R2 is connected with one end of a resistor R1, the other end of the resistor R1 is connected with the rectification filter circuit and a voltage input terminal Vin, the other end of the resistor R3 and the anode of the voltage stabilizing diode ZD1 are grounded.

3. A phase-conversion PWM circuit according to claim 2, characterized in that The rectification filter circuit (3) comprises diodes D1 and D2, the anode of the diode D1 is connected with an alternating current input terminal AC_L, the cathode of the diode D1 is connected with the other end of the resistor R1, the anode of the diode D2 is connected with an alternating current input terminal AC_N, the cathode of the diode D2 is connected with the other end of the resistor R1, and the alternating current input terminal AC_L and the alternating current input terminal AC_N are connected with the phase dimmer.

4. A phase-conversion PWM circuit according to claim 2 or 3, characterized in that The auxiliary power supply (5) is a 5V direct current voltage, one end of a resistor R5 is connected with the 5V direct current voltage, and the other end of the resistor R5 is connected with the drain electrode of the MOS tube Q1.

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