Torben
Well-Known Member
Hi all,
I have an SCR I need to test. I don't have a dedicated device for testing SCRs, although I do have a relatively cheap multimeter with a BJT socket on it it, if that helps. (This is part of the repair project discussed in this thread).
I've tried this test: Testing SCR - How To Test And Check Silicon Controlled Rectifier , and I wonder how trustworthy it is or whether it's at least a reasonable guide. I could always build a test circuit from the datasheet and measure that.
The important bit from the above page is:
By this test, my SCR is faulty. Not trusting the battery in the multimeter, I ran the test several times with the analog meter powered from the battery and several times powered from a bench power supply. All tests failed. The meter kicked when I touched anode to gate but failed to hold.
Thanks for any help,
Torben
I have an SCR I need to test. I don't have a dedicated device for testing SCRs, although I do have a relatively cheap multimeter with a BJT socket on it it, if that helps. (This is part of the repair project discussed in this thread).
I've tried this test: Testing SCR - How To Test And Check Silicon Controlled Rectifier , and I wonder how trustworthy it is or whether it's at least a reasonable guide. I could always build a test circuit from the datasheet and measure that.
The important bit from the above page is:
If you don't have this tester for checking SCR, I'm showing you another easy way on how to test SCR fast. You need an analog meter set to X1 ohm. Place the red probe to the Cathode and black probe to the Anode pin. At this time the meter doesn't show any reading. Now gently move the black probe and touch the Gate pin (the black probe still touching the Anode pin) and you will notice the meter's pointer will kick as shown at the picture (low resistance).
Removing the black probe from the GATE pin (the black probe still touching the Anode pin) you would noticed that the resistance continues to be there (low resistance). This is due to the conduction of SCR as the meter battery is usually able to supply current more than the holding current. If at this stage you removed the black probe from the Anode pin and connect it back, the pointer will dropped back to infinity (high resistance). If the SCR could hold the resistance then the SCR is considered good. If it can't hold then the SCR is faulty.
By this test, my SCR is faulty. Not trusting the battery in the multimeter, I ran the test several times with the analog meter powered from the battery and several times powered from a bench power supply. All tests failed. The meter kicked when I touched anode to gate but failed to hold.
Thanks for any help,
Torben