Transformer drive circuit

Abstract

The utility model relates to the technical field of electronics and electrics, in particular to a transformer drive circuit which can overcome stray capacitance of a transformer in the switching-on and switching-off process, reduce EMI (Electro-Magnetic Interference) and further improve the output quality of subsequent signals. The driving assembly is connected with a primary coil end of a transformer, the rectifying and filtering circuit is connected with a secondary coil end of the transformer, the driving assembly comprises a triode Q1, a triode Q2, a diode D1 and a capacitor C1, the triode Q1 is of an NPN type, the triode Q2 is of a PNP type, the triode Q1 and the triode Q2 form a push-pull circuit, the voltage stabilizing diode D1 is connected between an e pole and a c pole of the triode Q2, and the capacitor C1 is connected with the rectifying and filtering circuit. After the capacitor C1 is connected with the negative electrode of the voltage stabilizing diode D1, the other end of the capacitor C1 is connected with the primary coil of the transformer, and the other end of the primary coil of the transformer is grounded.

Description

Technical fields:

[0001] This utility model relates to the field of electronic and electrical technology, specifically a transformer drive circuit that can overcome the parasitic capacitance of the transformer during the switching on and off process, reduce EMI, and thus improve the quality of subsequent signal output. Background technology:

[0002] Traditional transformer drive circuits suffer from poor coupling between the primary and secondary coils during operation, leading to parasitic capacitance, unnecessary LC oscillations, high EMI, and degraded output signal quality. Therefore, reducing the parasitic capacitance of the transformer drive circuit is essential to improve the quality of subsequent electrical signals. Summary of the Invention:

[0003] This invention addresses the shortcomings and deficiencies of existing technologies by proposing a transformer drive circuit with a reasonable structure, low cost, and the ability to significantly reduce unnecessary LC oscillations in the circuit, thereby improving the quality of subsequent electrical signal output.

[0004] This utility model achieves its purpose through the following measures:

[0005] A transformer drive circuit is characterized by comprising a drive component connected to the primary coil of the transformer and a rectifier and filter circuit connected to the secondary coil of the transformer. The drive component includes a transistor Q1, a transistor Q2, a diode D1, and a capacitor C1, wherein transistor Q1 is NPN type, transistor Q2 is PNP type, transistors Q1 and Q2 form a push-pull circuit, a Zener diode D1 is connected between the emitter and collector of transistor Q2, capacitor C1 is connected to the cathode of Zener diode D1, and the other end of capacitor C1 is connected to the primary coil of the transformer, the other end of the primary coil of the transformer is grounded.

[0006] The driving component of this utility model also includes a transistor Q3, which is an NPN type. The base (b) of transistor Q3 is connected in series with resistor R1, and the other end of resistor R1 is connected to the PWM signal input terminal. The emitter (e) of transistor Q3 is grounded, and the collector (c) of transistor Q3 is connected to a pull-up resistor R2. The other end of pull-up resistor R2 is connected to a 24V high potential. Resistor R3 is connected between resistor R1 and the PWM signal input terminal. Resistor R3 and resistor R4 are connected in series, and the other end of resistor R4 is connected to +24V. One end of resistor R5 is connected between resistors R3 and R4, and the other end is grounded. The emitter of transistor Q3 is grounded. Resistors R7 and R6 are connected in parallel and then in series with resistor R8. The other end of resistor R8 is connected to the base of transistor Q2. The other ends of resistors R7 and R6 are both grounded. One end of resistor R9 is connected to the base of transistor Q1, and the other end is connected to the collector of transistor Q2.

[0007] The secondary coil of the transformer described in this utility model is connected to a rectifier and filter circuit. The rectifier and filter circuit includes a diode D2, a capacitor C2, and a capacitor C3. The positive terminal of the diode D2 is connected to one end of the secondary coil, and the other end of the secondary coil is grounded. The negative terminal of the diode D2 is connected in series with the capacitors C2 and C3 and then grounded.

[0008] The transformer described in this utility model can be a transformer with a pull-out split frame, comprising a frame, coils, and a magnetic core. The frame has a pull-out split structure, including an outer frame and a pull-out sleeve. The outer frame has a through hole, and the pull-out sleeve is located in the through hole in the center of the outer frame. The inner wall of the pull-out sleeve and the through hole in the center of the outer frame have a gap for winding the coil. The magnetic core is disposed in the pull-out sleeve. The coil includes a primary coil and a secondary coil, which are wound on the outer wall of the pull-out sleeve and the outer wall of the outer frame, respectively. During operation, the number of turns of the primary or secondary coil of the transformer can be flexibly adjusted by adjusting the number of turns of the coil on the outer wall of the pull-out sleeve.

[0009] Compared with the prior art, this invention has significant advantages such as reasonable structure, low cost, ability to significantly reduce unnecessary LC oscillations in the circuit, and thus improve the quality of subsequent electrical signal output. Attached image description:

[0010] Appendix Figure 1 This is a schematic diagram of the utility model.

[0011] Appendix Figure 2 This is the circuit schematic diagram of this utility model.

[0012] Appendix Figure 3 This is a schematic diagram of the outer frame structure of the transformer in an embodiment of this utility model.

[0013] Appendix Figure 4 This is a schematic diagram of the pull-out sleeve in an embodiment of this utility model.

[0014] Reference numerals: 1. Drive component; 2. Rectifier and filter circuit; 3. Outer frame; 4. Pull-out sleeve; 5. Annular boss; 6. Winding groove. Detailed implementation method:

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Example:

[0017] As attached Figure 1As shown, this example proposes a transformer drive circuit, which includes a drive component connected to the primary coil of the transformer and a rectifier and filter circuit connected to the secondary coil of the transformer. The drive component includes transistor Q1, transistor Q2, diode D1, and capacitor C1, wherein transistor Q1 is NPN type, transistor Q2 is PNP type, transistor Q1 and transistor Q2 form a push-pull circuit, and Zener diode D1 is connected between the emitter and collector of transistor Q2. After capacitor C1 is connected to the cathode of Zener diode D1, the other end of capacitor C1 is connected to the primary coil of the transformer, and the other end of the primary coil of the transformer is grounded.

[0018] As attached Figure 1 As shown, the driving component described in this example also includes transistor Q3, which is an NPN type. The base of transistor Q3 is connected in series with resistor R1, and the other end of resistor R1 is connected to the PWM signal input terminal. The emitter of transistor Q3 is grounded, and the collector of transistor Q3 is connected to pull-up resistor R2. The other end of pull-up resistor R2 is connected to a 24V high potential. Resistor R3 is connected between resistor R1 and the PWM signal input terminal. Resistor R3 and resistor R4 are connected in series, and the other end of resistor R4 is connected to +24V. One end of resistor R5 is connected between resistor R3 and resistor R4, and the other end is grounded. The emitter of transistor Q3 is grounded. Resistors R7 and R6 are connected in parallel and then in series with resistor R8. The other end of resistor R8 is connected to the base of transistor Q2. The other ends of resistors R7 and R6 are both grounded. One end of resistor R9 is connected to the base of transistor Q1, and the other end is connected to the collector of transistor Q2.

[0019] As attached Figure 2 As shown, the secondary coil of the transformer in this example is connected to a rectifier and filter circuit. The rectifier and filter circuit includes a diode D2, a capacitor C2, and a capacitor C3. The positive terminal of the diode D2 is connected to one end of the secondary coil, and the other end of the secondary coil is grounded. The negative terminal of the diode D2 is connected in series with the capacitors C2 and C3 and then grounded.

[0020] As attached Figure 3 As shown, the transformer can be a transformer with a pull-out split frame, which includes a frame, coils, and a magnetic core. The frame has a pull-out split structure, including an outer frame 3 and a pull-out sleeve 4. The outer frame 3 has a through hole, and the pull-out sleeve 4 is located in the through hole in the center of the outer frame 3. The inner wall of the pull-out sleeve and the through hole in the center of the outer frame 3 have a gap for winding the coil. The magnetic core is set in the pull-out sleeve 4. The coil includes a primary coil and a secondary coil, which are wound on the outer wall of the pull-out sleeve and the outer wall of the outer frame 3, respectively. During operation, the number of turns of the primary or secondary coil of the transformer can be flexibly adjusted by adjusting the number of turns of the coil on the outer wall of the pull-out sleeve 4.

[0021] The through-hole on the outer frame 3 is rectangular, and the cross-section of the pull-out sleeve 4 is rectangular to match the through-hole. Annular bosses 5 are provided at both ends of the pull-out sleeve 4 to seal the gap between the outer frame 3 and the pull-out sleeve 4. Winding grooves 6 are formed on the outer wall of the outer frame 3, and partitions are provided between adjacent winding grooves 6. These partitions are continuously arranged on at least two outer walls of the rectangular through-hole to ensure the coil is blocked. The magnetic core is made of silicon steel sheet, silicon steel sheet, or ferrite core, and is fixed to the pull-out sleeve by adhesive application. The primary coil is wound on the outer wall of the pull sleeve 4, and the primary coil has two or more pins; the secondary coil is wound on the outer wall of the outer frame, and the secondary coil has two or more pins; by opening a through hole in the outer frame 3 and putting the pull sleeve 4 inside the through hole, the relative position of the coil wound on the pull sleeve 4 and the coil wound on the outer frame 3 changes when the pull sleeve 4 moves, thereby changing the effective cutting area of ​​the magnetic field lines during the operation of the transformer, so as to adapt to the assembly requirements of the functional circuit later.

[0022] Compared with the prior art, this invention has significant advantages such as reasonable structure, low cost, ability to significantly reduce unnecessary LC oscillations in the circuit, and thus improve the quality of subsequent electrical signal output.

Claims

1. A transformer drive circuit, characterized in that, The circuit includes a drive assembly connected to the primary coil of a transformer and a rectifier and filter circuit connected to the secondary coil of the transformer. The drive assembly includes transistors Q1 and Q2, diode D1, and capacitor C1. Transistor Q1 is an NPN type, and transistor Q2 is a PNP type. Transistors Q1 and Q2 form a push-pull circuit. Zener diode D1 is connected between the emitter and collector of transistor Q2. After capacitor C1 is connected to the cathode of Zener diode D1, its other end is connected to the primary coil of the transformer. The other end of the primary coil of the transformer is grounded.

2. The transformer drive circuit according to claim 1, characterized in that, The driving component also includes a transistor Q3, which is an NPN type. The base (b) of transistor Q3 is connected in series with resistor R1, and the other end of resistor R1 is connected to the PWM signal input terminal. The emitter (e) of transistor Q3 is grounded, and the collector (c) of transistor Q3 is connected to a pull-up resistor R2. The other end of pull-up resistor R2 is connected to a 24V high potential. Resistor R3 is connected between resistor R1 and the PWM signal input terminal. Resistors R3 and R4 are connected in series, and the other end of resistor R4 is connected to +24V. One end of resistor R5 is connected between resistors R3 and R4, and the other end is grounded. The emitter of transistor Q3 is grounded. Resistors R7 and R6 are connected in parallel and then in series with resistor R8. The other end of resistor R8 is connected to the base of transistor Q2. The other ends of resistors R7 and R6 are both grounded. One end of resistor R9 is connected to the base of transistor Q1, and the other end is connected to the collector of transistor Q2.

3. The transformer drive circuit according to claim 1, characterized in that, The secondary coil of the transformer is connected to a rectifier and filter circuit, which includes a diode D2, a capacitor C2, and a capacitor C3. The positive terminal of the diode D2 is connected to one end of the secondary coil, and the other end of the secondary coil is grounded. The negative terminal of the diode D2 is connected in series with the capacitors C2 and C3 and then grounded.

4. A transformer drive circuit according to claim 1, characterized in that, The transformer is a transformer with a pull-out split frame, comprising a frame, coils, and a magnetic core. The frame has a pull-out split structure, including an outer frame and a pull-out sleeve. The outer frame has a through hole, and the pull-out sleeve is located in the through hole in the center of the outer frame. The inner wall of the pull-out sleeve and the central through hole of the outer frame have a gap for winding the coil. The magnetic core is disposed in the pull-out sleeve. The coil includes a primary coil and a secondary coil, which are wound on the outer wall of the pull-out sleeve and the outer wall of the outer frame, respectively.

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