Controllable silicon tester production, SCR Tester
Keywords: thyristor, test circuit
Author: Li Changwen
A production unit proposes whether it is designed to make a simple and practical thyristor tester for prenatal screening. After understanding its routine test items and parameters, a tester is produced according to the circuit shown by the accompanying drawings. After the user uses the test method, the test method is simple and practical, and the test results are accurate.
The circuit can measure the positive reverse block voltage VDRM, VRRM, triggered the conduction voltage Vg, triggered the conductive current Ig, and on-maintain current IH, which requires a controllable silicon that is resistant to 1800 V. Touch generating voltage is within 5V, the trigger current and the maintenance current should be around 100 mA. The high-voltage generating circuit uses 5 2W, 220V variable 12V small transformer initial secondary transformer, that is, the 12V terminal of 5 small transformer seconds with the power transformer 12V output is connected in parallel, and the first end of the 5 small transformers is connected in series. Such a design is not to use high-frequency oscillation and boost transformer production method, and the other is to solve the problem of high voltage winding insulation and breakdown.
The 1100V AC voltage differs from the multiplier to obtain a DC voltage above 2000V.
The tandem used in the rectifier diode and the filter capacitor is to increase the pressure, and the 6 1mΩ resistance is set to a series electrolytic capacitance.
The 2000V voltage is added to both ends of 2.2MΩ potentiometer. The intermediate slip arm can output an adjustable voltage of 0V ~ 2000V, and the voltage meter and current table are provided before receiving the controllable silicone anode (cathode), adjustment time to test The 2.2mΩ potentiometer causes the output voltage to reach a turning voltage (breakdown voltage), the voltage meter is constantly rising and the current table does not move, and the voltage gauge is no longer rising when the output voltage reaches the turning voltage. The current table begins to rise. At this time, the voltage meter is indicated by the turning voltage. This voltage value is subtracted from 100V is VDRM, and the function switch consisting of four-knife four-throw-wide switch is from 1 to 2, then from low to high test once is VRRM. The 12V power supply end of the boost transformer group is provided with a relay normally open contact. When testing trigger and maintenance, the function switch will disconnect the relay and the high voltage portion stops working. Another set of 12V output from the power transformer is rectified by 7812 regulated anode to supply the anode, and then powered by a trigger voltage adjustment circuit composed of transformers C2073 and C1815 by 7806. When the function switch is converted to the 3 gear VG, IG adjusts 4.7kf1 potentiometer, it can be seen that the trigger voltage meter and trigger current table are rising, and when turning on the light-emitting diode is lit, it means that the thyristor has triggered, guide Paste the two table indication values are triggered voltage and trigger currents, respectively. Press the reset shutdown button to retest the reset button again. Converting the function switch to 4 gear is the maintenance current test, adjust the 220Ω potentiometer (adjustable resistor) to the minimum, press the on-to-trigger button, maintain the current table will indicate about 100mA, slowly increase the resistance, and maintain the current table will slowly retreat When the current table pointer suddenly begins quickly returns to the current, it is the maintenance current. Only 2000V tables in the five heads need to be used in series with a few tens of megabo resistance. Other heads can be met to observe with a range.
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