KCZ2 single-phase bridge full control (half control) bridge open loop trigger board

I. Overview
   KCZ2 single-phase bridge type full control (semi-control) open loop trigger board is modified and developed based on users' opinions on the original KJZ2 board. Compared with KJ2 board, it has the following advantages and characteristics:
1. With rectification and voltage stabilization links, it can generate +15V, -15V and +24V power supply in addition to the board itself, but also for user systems.
2. The imported original TCA785 is used to replace KJ004, and the 555 is used to replace KJ042, so the overall size of the board is reduced, the structure is more compact, the integration is further improved, and the number of discrete components used is greatly reduced.
 3. The two-sided connectors of the original plug-in box type are changed to two vertical-board connectors. The plug-in box is not needed in use, and the installation is more convenient and flexible.
 4. The board contains a differentiator and output pulse maximum control angle ?emax and minimum control angle ?emin limiter, so it is more convenient to cooperate and apply with the regulator.
 5. The output is a pulse train, which can reduce the size of the pulse transformer and the power of the working power supply.
 6. The board contains over-current protection and external fault protection functions. After protection, one is to seal the pulse, and the other is to break the main circuit of the user system and use it more reliably.
 7. It can be controlled inside or outside the board to control the phase shift to meet the needs of different users.

II. Main technical parameters
1. Input AC voltage: dual 18V/0.5A;
2. Input phase shift control voltage range: +0゛12V;
 3. Phase shift range: 170<;
 4. Output pulse form: pulse train;
 5. With internal overcurrent or overvoltage protection function;
 6. With external fault protection input port (active low);
 7. Output pulse g1, g2 current amplitude 200mA;
8. Output two trigger pulses with phase difference of 180 degrees each other, which can be used in single-phase bridge type full control (half control) and single-phase double half-wave controllable rectification system or single-phase AC voltage regulating system.
9. It can be matched with external PI regulator to form a closed loop control system;
 10. Dimensions: length〜width〜height=146mm〜85mm〜30mm;
 11. Installation size: four holes 4.5mm, hole distance 137mm〜75mm;
 12. The capacity of the normally closed contact of the protection relay is 220V/1A or 380V/0.5A.

Three, how to use
   The schematic diagram of the main components of the KCZ2 board is shown in Figure 1. It is obvious from Figure 1 that there are six potentiometers in the board, and two connectors are used for external leads.



Figure 1 KCZ2 single-phase thyristor open-loop trigger board component layout diagram

The function and adjustment method of each potentiometer:
1. W1 is the current (or voltage) sampling adjustment potentiometer. It is adjusted clockwise to decrease the sampling value, and counterclockwise to increase the sampling value.
2. W2 is the over-current (or over-voltage) protection threshold adjustment potentiometer. Adjust the protection threshold clockwise to decrease, and adjust the protection threshold counterclockwise to increase.
 3. W3 is the control given potentiometer in the board, counterclockwise to adjust the given voltage to increase, clockwise to adjust the given voltage to decrease, when the user connects an external potentiometer, please turn the potentiometer to the end counterclockwise, that is, the internal given potential The device is located at the given maximum position.
 4. W4 is the output voltage adjustment potentiometer of the differentiator. The output voltage of the differentiator is adjusted clockwise to decrease, and the output voltage of the differentiator is adjusted counterclockwise to increase. The best position of the potentiometer is to satisfy that the given voltage is the maximum when the output voltage of the differentiator is Zero (corresponding to the trigger pulse control angle α is zero degrees), when the given voltage Ug is zero, the output voltage of the differentiator is the maximum (corresponding to the trigger pulse control angle α is 180<), generally it has been adjusted before leaving the factory, and the user does not need to adjust .
 5. W5 is the maximum ?e angle limiter adjustment potentiometer. It is adjusted clockwise to increase the maximum ?e angle limiter value, and counterclockwise to adjust the maximum ?e angle limiter value to decrease. Generally, it has been adjusted before leaving the factory, and the user does not need to adjust it.
 6. W6 is a synchronous sawtooth wave amplitude adjustment potentiometer, clockwise adjusts the sawtooth wave amplitude to increase, and counterclockwise adjusts the sawtooth wave amplitude to decrease. Generally, it has been adjusted before leaving the factory, and the user does not need to adjust.
 The external wiring method of the connector:
1. The 18V, D, 18V in the connector S1 are connected to a double AC 18V winding of a transformer with a center tap, where D is connected to the center tap, and If1 and If2 are connected to the current (or voltage) signal sampling value, when the current sampling value is connected, The board has an over-current protection function. When the voltage signal sampling value is connected between If1 and If2, it is over-voltage protection. L is connected to the external fault protection input signal, and the low voltage is valid. The internal over-current (or over-voltage) protection is OR The relationship between +15V, -15V is the power supply voltage signal provided to the user, Ug, P, D are respectively connected to the middle head and two fixed ends of an external set potentiometer (resistance value not less than 5.6K, power not less than 0.5W) .
2. The connection point between A and B in the connector S2 is a normally closed contact, which is usually connected in the main contactor circuit of the user system for protection and then disconnects the main circuit of the user system, and +24V, g1; +24V, g2 They are respectively used to connect the input terminals of the pulse final stage board. When the KCZ2 board is used in a single-phase half-wave controllable system, only any one of +24V, g1 (or +24V, g2) can be used, and the KCZ2 board is used for In the case of a single-phase bridge-type fully-controlled rectifier circuit, +24V, g1 and +24V, g2 are respectively connected to the input of two pulse power amplifier units.

IV. Application examples
The above structure of the KCZ2 board determines that it can not only be used as a thyristor in the main circuit for single-phase bridge half-control, single-phase bridge full-control, single-phase half-wave controllable, and single-phase dual-half-wave controllable rectifier systems. Phase trigger can also be used in single-phase AC voltage regulation system.
1. For single-phase AC voltage regulation system, the principle circuit of KCZ2 board for this type of system is shown in Figure 2. CT in the figure is a current transformer, and the system uses the overcurrent protection function in the board.


Figure 2 KCZ2 board used in single-phase AC voltage regulation system diagram

Figure 3 Diagram of KCZ2 board used in single-phase bridge-type fully-controlled rectification system