1、The application field of SCR module:
The intelligent module is widely used in temperature control, dimming, excitation, electroplating, electrolysis, charging and discharging, electric welding machine, plasma arc, inverter power supply and so on, which need to adjust and transform the power energy. Such as industrial, communications, military and other electrical control, power supply and so on. It can also be connected to the multi-function control board through the module's control port to realize the functions of steady current, steady voltage and soft start. It can also achieve overcurrent, overvoltage, over temperature and equal protection function.
2、Control mode of SCR module:
Through the input module, a adjustable voltage or current signal is controlled by the input module. The output voltage of the module can be adjusted smoothly by adjusting the size of the signal to realize the process of the output voltage of the module from 0V to any point or all.
The voltage or current signal can be taken from various control instruments, computer D/A output, and the potentiometer directly from the DC power supply. The control signals are 0 to 5V, 0 to 10V and 4 to 20mA, which are commonly used in control.
3、Control port and control line of SCR module
The module control terminal interface has three forms, namely, 5 pins, 9 pins and 15 pins, corresponding to the control lines of 5 cores, 9 cores and 15 cores respectively. Products using voltage signals only use the first five pin ports, and the rest are empty feet. Using the 9 pins of the current signal as signal input, the shielded copper wire of the control line should be welded to the DC power supply ground wire. When connecting, be careful not to short circuit with other terminals, so as not to fail to work properly or burn out the module.
Module control port socket and control line socket are numbered, please match one by one, do not reverse. The above six ports are the basic ports of the module, and the other ports are special ports. They are only used in multi-functional products, and the rest of the common pressure regulating products are empty feet.
4、Color contrast table of each pin function and control line
Pin function foot pin and corresponding lead color 5 core connector 9 core connector 15 core connector+12V5 (Red)1 (Red)1 (Red)GND4 (Black)2 (Black)2 (Black)GND13 (Black) 3 (Black And White) 3 (Black And White)CON10V2 (Middle Yellow)4 (Middle Yellow)4 (Middle Yellow)TESTE1 (Orange)5 (Orange)5 (Orange)CON20mA 9 (Orange)9 (Orange)
5、The necessary conditions for the operation of SCR modules:
The following conditions must be used in the use of modules:
（1）+12V DC power supply: the power supply of the internal control circuit of the module.
①Output voltage requirements: +12V power supply: 12 + 0.5V, ripple voltage less than 20mV.
②Output current requirement: nominal current less than 500 ampere product: I+12V > 0.5A, nominal current greater than 500 ampere product: I+12V > 1A.
（2）Control signal: 0 ~ 10V or 4 ~ 20mA control signal, used to adjust the output voltage control signal, positive electrode CON10V or CON20mA, negative electrode to GND1.
（3）Power supply and load: the power supply is usually power grid. The voltage below 460V or the power supply transformer is connected to the input terminal of the module, the load is the electrical appliance, and the output terminal of the module is connected.
6、The relationship between the conduction angle and the output current of the module：
The conduction angle of the module is directly related to the maximum current that the module can output. The nominal current of the module is the maximum current that can be output when the maximum conduction angle is reached. The peak value of output current is very small when the small conduction angle (the ratio of output voltage to input voltage is small). But the effective value of the current is very small (DC instrument generally shows the average value, the AC instrument shows the non sinusoidal current is smaller than the actual value). But the effective value of the output current is very large. The heating of semiconductor devices is directly proportional to the square of the effective value, which makes the module seriously heat or even burn down. Therefore, the module should select more than 65% of the maximum conduction angle, and the control voltage should be above 5V.
7、Selection method of silicon controlled silicon module specification
Considering that the silicon controlled products are generally non sinusoidal currents, there is a problem of conduction angle and load current has some volatility and instability factors. And the SCR chip is poor in resistance to current impact. When selecting the module current specifications, a certain allowance must be set aside. The recommended selection method can be calculated according to the following formula:
I>K×I(load)×U(MAX)∕U(Reality)
K ：safety factor，Resistive load K= 1.5，inductive load K= 2；
I(load)：The maximum current flowing through the load； U(real)：The minimum voltage on the load；
U(Max)：The maximum voltage that the module can output；（The three-phase rectifier module is 1.35 times the input voltage, and the single-phase rectifier module is 0.9 times of the input voltage, and the other specifications are 1 times.）；
I：The minimum current of the module needs to be selected, and the nominal current of the module must be greater than that value.
The cooling condition of the module is directly related to the service life and short time overload capacity of the product. The lower the temperature, the larger the output current of the module, so the radiator and fan must be installed. It is recommended that products with overheat protection function and water cooling and cooling conditions give priority to water cooling. After rigorous calculation, we have determined the radiator types of different types of products. It is recommended that the radiator and fan installed by the manufacturer should be selected according to the following principles:
1、The wind speed of axial-flow fan should be greater than 6m/s
2、It is necessary to ensure that the temperature of the bottom plate of the module is not greater than 80 ℃ at normal working temperature.
3、When the module load is lighter, the size of the radiator can be reduced or the natural cooling will be adopted.
4、When the natural mode cooled, the air around the radiator can realize convection and appropriately increase the radiator area.
5、The screws of all fastening modules must be tightened, and the terminals are firmly connected to reduce the secondary heat generation. Between the module baseplate and the radiator must be coated with a thermal conductive silicone grease or a heat pad on the bottom plate to achieve the best cooling effect.
8、Installation and maintenance of silicon controlled module
（1）The screws of all fastening modules must be tightened, and the terminals are firmly connected to reduce the secondary heat generation. Between the module baseplate and the radiator must be coated with a thermal conductive silicone grease or a heat pad on the bottom plate to achieve the best cooling effect.
（2）Assemble the radiator and fan according to the requirements and fix them vertically in the appropriate position of the chassis.
（3）Tie the copper wire tightly with the terminal belt. It is best to dip tin into the insulating heat shrinkable tube. Heat and shrink with hot air. The terminal is fixed on the module electrode and maintained good pressure contact. It is strictly forbidden to directly connect the cable copper wire to the module electrode.
（4）In order to extend the service life of the product, it is recommended to maintain it once every 3-4 months, change the thermal silicone grease, remove the dust on the surface, and fasten all the screws.
