The bidirectional thyristor can be equivalent to two unidirectional thyristors in reverse parallel connection, as shown in Figure 4-47. The bidirectional thyristor can control bidirectional conduction, so the other two electrodes except the control electrode G are no longer divided into anode and cathode, but are called main electrodes T1 and T2.
When a trigger voltage is applied to the control electrode G, the bidirectional thyristor is turned on, and the well remains in the conductive state after the trigger voltage disappears. The current can flow from T1 to T2 through VS2, or from T2 to Tl through VS1. When the current is less than the holding current of the thyristor, the thyristor is turned off.
The working principle of bidirectional thyristorThe unidirectional thyristor can only conduct unidirectionally, while the bidirectional thyristor can conduct bidirectionally. Below, the editor of Aite Trading uses the circuit shown in Figure 1-13 to illustrate the two triggering conduction modes of the triac.
(1) When a forward voltage is applied between T2 and T1 (ie UT2>UT1), as shown in Figure 1-13 (a).
In this case, if there is no voltage at the G pole, there will be no conduction between the T2 and T1 poles; if a positive voltage is applied between the G and T1 poles (ie UG>UT1), the T2 and T1 poles will immediately conduct. The current flows in from the T2 pole and flows out from the T1 pole. At this time, the G pole voltage is removed, and the T2 and T1 poles are still in a conducting state. That is to say, when UT2>UG>UT1, the bidirectional thyristor is turned on, and the current flows from the T2 pole to the T1 pole. After the G pole voltage is removed, the thyristor continues to be in the conducting state.
(2) When reverse voltage is applied between T2 and T1 (ie UT2<UT1), as shown in Figure 1-13(b).
In this case, if there is no voltage at the G pole, there is no conduction between the T2 and T1 poles; if a reverse voltage is applied between the G and T1 poles (ie UG<UT1), the T2 and T1 poles will conduct immediately. The current flows in from the T1 pole and flows out from the T2 pole. At this time, the G pole voltage is removed, and the T2 and T1 poles are still in a conducting state. In other words, when UT1>UG>UT2, the bidirectional thyristor is turned on, and the current flows from the T1 pole to the T2 pole. After the G pole voltage is removed, the thyristor continues to be in the conducting state.
After the bidirectional thyristor is turned on, the G pole voltage is removed, and it will continue to be in the on state. In this case, to make the bidirectional thyristor from conduction to cutoff, any of the following methods can be used.
1) Reduce the current flowing through the main electrodes T1 and T2 to below the sustain current.
2) Make the voltage between the main electrodes T1 and T2 0 or change the polarity of the voltage between the two electrodes.
AC Input : 100V to 240V, DC Output: 12 volt at 2 amp rating . Please refer to the ASIN :B0746GCGQ8 if u need 10 units.
Type : Regulated Switching Power Supply with 2.1mm x 5.5mm plug , center positiveManufactured with high quality material and built-in protection of over current, over voltage, short circuits .
COMPACT DESIGN and LOW CONSUMPTION makes it ideal for taking around and using at home.
12v wall charger,12v switching adapter,(12V/2A) Switching Mode Power Adapter Wall Charger,12V 2A Power Supply Adapter,12 Volt 2 Amp Power Adapter,12V 3A Power Supply Adapter,12v3a wall charger
Shenzhen Waweis Technology Co., Ltd. , https://www.waweispowerasdapter.com