Hi, can anyone tell me what may cause the base-collector voltage to be over 1000V? If the HOT is connected B-C voltage is over 1000V and voltage at base is less than 1 volt, if i remove the HOT, B-C voltage drops to 112V and Base still is less than 1V.
also over 1000V... Can anyone tell me what is going on? What can cause these very high voltages?
Thanks.
onyxx: The high voltages you are reading with your meter are a result of back emf as a result of fast switching of the transformer's input power.... that is why the voltage ratings for Collector to Base and Collector to Emitter have to be upwards to 1500 volts for these kinds of semiconductors that do the switching. You should not be measuring these points with your meter.... damage can easily result. Do a little reading a the website for this newsgroup at
If you use a cheap meter, you will get false readings due to the 1200 volt P-P AC pulse @ the collector, when the HOT is conducting. You can damage you meter, or kill your T.V., if your not careful. Sky.
Voltage at chopper transistor´s collector (low voltage power supply)is also over 1000V... Can anyone tell me what is going on? What can cause these very high voltages?
Thanks.
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