How to measure a unidirectional thyristor with a digital multimeter
Unidirectional thyristor performance identification
Unidirectional thyristor referred to as thyristor (SCR), formerly known as silicon controlled, is a controlled rectifier components, its circuit symbol, A for the anode, K for the cathode, G for the control pole.
Unidirectional thyristor performance identification
Unidirectional thyristor referred to as thyristor (SCR), the old name of the silicon control, is a controlled rectifier components, the circuit symbols are shown in Figure 1, A is the anode, K is the cathode, G is the control pole.
(1) Discriminate the electrode with a red meter stick fixed contact with any electrode unchanged, the black meter stick were in contact with the remaining two electrodes, if the contact with a pole once displayed 0.2 ~ 0.8V, contact with another electrode when the display overflow, then the red meter stick connected to the G, the display overflow of the black meter stick connected to the A, the other pole is K. If the results of the measurement is not the above results, you need to change the red meter stick electrodes and repeat the above steps until the correct results. correct result.
(2) identify the trigger characteristics of the digital multimeter diode block can provide the test current is only 1mA or so, it can only be used to investigate the trigger ability of the low-power unidirectional thyristor. The operation method is as follows: with the red meter stick fixed contact A unchanged, the black meter stick contact K, this time should show overflow (off state). Then the red meter stick in the premise of keeping connected with A to touch G, at this time the display value is generally below 0.8V (turn on state). Immediately disengage the red meter stick from the control pole, the on-state will continue to be maintained. If repeated multiple tests are so, that the tube trigger sensitive and reliable. This method is only applicable to maintain a small current tube.
