audioguru2
- Apr 6, 2004
- 12,026
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Since a Diac has a breakdown voltage of 20V or 30V, then obviously the 1.5V from a diode tester won't work.
Connect the output of a variable voltage source through a series 1k resistor to the Diac with its other pin grounded to the voltage source. When the voltage is raised to 20V or 30V (the rating of the Diac) then it will suddenly conduct and cause a low voltage across it.
I think Diacs are bi-directional, so reverse its connections and repeat the test.
Connect the output of a variable voltage source through a series 1k resistor to the Diac with its other pin grounded to the voltage source. When the voltage is raised to 20V or 30V (the rating of the Diac) then it will suddenly conduct and cause a low voltage across it.
I think Diacs are bi-directional, so reverse its connections and repeat the test.
A
Alun
- Jan 1, 1970
- 0
I was going to post but You've beaten me to it, anyway I'd go a bit higher than 30V, I'd say 40V as some diacs have a trigger voltage of 32V or even 36V.
audioguru2
- Apr 6, 2004
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Yeah Alun,
Some Diacs have a higher breakdown voltage than only 30V.
Maybe the 1k resistor I recommended should be increased in value to test at a lower trigger current. ;D
Some Diacs have a higher breakdown voltage than only 30V.
Maybe the 1k resistor I recommended should be increased in value to test at a lower trigger current. ;D
A
Alun
- Jan 1, 1970
- 0
I was going to suggest 2k2 but I don't know if the current will be high enough, and you'll need a 1W resistor for 30V or 1.6W for 40V, you might be able to get away with 1W @ 40V for a short time but I cerntainly wouldn't leave it running.
