SCR Current Ratings

jojo September 14, 2009 No Comments
Current ratings of an SCR The current carrying capability of an SCR is solely determined by the junction temperature. Except in case of surge currents, in no other case the junction temperature is permitted to exceed the permissible value....
read more

Voltage ratings of an SCR

jojo September 14, 2009 3 Comments
SCR Voltage Ratings (i) Breakover Voltage. The minimum forward voltage, when the gate is open, at which SCR starts conducting heavily (that is turned-on) is called the breakover voltage. To specify this value, the gate is in the open-circuit...
read more

Ratings and Specifications of an SCR

jojo September 14, 2009 No Comments
SCR-Ratings and Specifications The performance of an SCR is affected by the junction temperature, because of change in carrier densities in the four layers and the junction temperature naturally depends upon the internal power losses of the device and...
read more

SCR Turning OFF methods

jojo September 14, 2009 No Comments
Turning-off Methods of an SCR As already mentioned in previous blog post, once the  SCR is fired, it remains on even when triggering pulse is removed. This ability of the SCR to remain on even when gate current is...
read more

Turn on methods of an SCR

jojo September 14, 2009 3 Comments
How to turn ON an SCR ? As mentioned earlier, the SCR can be switched on either by increasing the forward voltage beyond forward break over voltage VFB0 or by applying a positive gate signal when the device is...
read more

Dynamic Characteristics of an SCR

jojo September 11, 2009 1 Comment
Turn-on and turn-off characteristics of an SCR are called the dynamic characteristics of the SCR. (a)    Turn-On Character­istic. The turn-on time charac­teristic shows the variation of current and voltage during turn-on. Turn-on time is defined as the time from the...
read more

SCR-Volt-ampere-Characteristics

jojo September 11, 2009 7 Comments
As already mentioned, the SCR is a four-layer device with three terminals, namely, the anode, the cathode and the gate. When the anode is made positive with respect to the cathode, junctions J1 and J3 are forward biased and...
read more

SCR-Principle of Operation

jojo September 10, 2009 23 Comments
How an SCR works?-Principle of Operation SCR Working Principle The SCR is a four-layer, three-junction and a three-terminal device and is shown in fig.a. The end P-region is the anode, the end N-region is the cathode and the inner...
read more

SCR-Silicon Controlled Rectifier

jojo September 18, 2009 2 Comments
Introduction to SCR-Silicon Controlled Rectifier As the terminology indicates, the SCR is a controlled rectifier constructed of a silicon semiconductor material with a third terminal for control purposes. Silicon was chosen because of its high temperature and power capabilities....
read more