What is a two-way trigger diode and how to detect it?
l What is a two-way trigger diode?
Bidirectional trigger diodes are also called end - to - end AC devices (DIAO), which have the advantages of simple structure and low price. A variety of control circuits can be built in conjunction with bidirectional thyristors.
The bidirectional trigger diode belongs to the three layer two end semiconductor device. When the voltage V at both ends of the device is less than the forward turning voltage V, the tube is in a high resistance state, and the negative resistance zone is entered when V>VBo. In the same way, when V exceeds the reverse turn. When the voltage is VBR, the tube can also enter the negative resistance zone. The symmetry of the turning voltage is expressed by delta VB, Delta VB=VBo andVBRI. The general requirement is delta VB<2V. The voltage withstand value (VBo) of bidirectional trigger diodes can be roughly divided into three grades: 20~ 60V, 100~ 150V, 200~ 250V.
l Detect two-way trigger diode
(1) Use the multimeter to place the multimeter in the RX1~RX10kΩ gear and measure the positive and reverse resistance of the bidirectional trigger diode. When it is normal, it should be infinity (because the forward and reverse voltage and reverse voltage are greater than 20V., that is larger than the cell voltage in the meter). In measurement, if the meter pointer swings, the tube can not be applied.
(2)The turning voltage diagram of the bidirectional trigger diode is a circuit diagram of the circuit for judging the turning voltage of a two-way trigger diode. The DIAC can be replaced by a MEM table instead of the power supply.
According to the specific turning voltage of the bidirectional trigger diode, the multimeter is placed in the corresponding voltage shift, and two values, one VBO and a Ver, are compared with the V.The smaller the difference between the absolute values of the two,the better the symmetry of the bidirectional trigger diode is.
In use, because the turning voltage of the bidirectional trigger diode has a symmetrical characteristic, it can be chosen from the data obtained in two times,the value is VBO, and the other is VBR.
This article is from Allicdata.