Talk:DIAC
Measuring DIACs (and other thyristors)
How can I measure diac and thyristor?
- The standard method is to use a "curve tracer", a specific kind of electronic test equipment that looks like an oscilloscope but can apply a variable, bipolar voltage to the device under test and measures the resulting current. Curve tracers can also apply base (trigger) bias and display how that affects the resulting change in the V-I curves.
You can kludge up a minimalist curve tracer using an ordinary oscilloscope, an isolation transformer, and a load resistor.
I'm not a registered user, so I'm not going to edit the article, but I wanted to point out that this statement: "It is similar to two Shockley or Zener diodes connected in inverse parallel." is blatantly false. Zener diodes have a point where they become virtually straight lines on the VI curve, but lack the negative resistance zone that a DIAC has. A DIAC acts a lot more like a trigger tube - once the voltage reaches the "trigger" point, the effective voltage across it suddenly drops to a very low value, and current will flow appropriately. Only when the current falls off does the voltage drop go back up.