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Registered Member #505
Joined: Sun Nov 19 2006, 06:42PM
Location: Yorkshire!
Posts: 329
If you look in this datasheet for UF4007 it shows a basic method for measuring trr
Here's another found from a quick google for for "measure reverse recovery time"
Your problem will be generating a 1kV pulse with sufficiently fast rise time. You could always test the rectifiers at several lower voltages and attempt to extrapolate out to 1kV. If it's linear, it could make life easier.
Also, it might be worth describing your problem in more detail in case anyone has a different approach.
Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062
Thanks for the tips :)
I bought some diodes on Ebay a while back which are supposed to be "fast" (300nS) 28KV 100mA black plastic diodes, but the output on my converter is pitiful. Even at 10KV input I am still getting a fraction of the correct output, and hardly any current.
Its possible I have a faulty diode but its strange that the "glass rectifier" stack made using diodes from CPC worked just fine until it fried.
Maybe I should have tested the diodes first? will try this next. -A
Registered Member #75
Joined: Thu Feb 09 2006, 09:30AM
Location: Montana, USA
Posts: 711
What is your "converter", and at what frequency are you driving it?
I don't think the voltage matters much for testing, since the diodes probably drop relatively little voltage during reverse recovery. Thus you could just attach a diode with a load resistor to a square-wave generator and put your scope across it. The output of a 555 is proably a bit weak to quickly charge the junction capacitance, so using a gate driver for the output stage of the signal generator would be a good idea.
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Measuring diode speed?
