Hi, Darin Hensley wrote: > Here is the diagram I tried to capture with my phone. With this helps any > I'm trying to see what is causing it?
The PC817 optocouplers are only specified for a collector-emitter voltage of 35V, so it is very likely one of them is breaking down when its tube is turned off. It might be a good idea to replace them with optocouplers that can withstand a higher voltage. Biasing to 85V won't work with these optocouplers, because (175V - 85V) = 90V > 35V. If the pin numbers in the schematic are correct, the optocoupler transistors are also connected in reverse (pin 3 = emitter to +HV), in which case the specified voltage is only 6V. However the position of the pins makes me think that very likely, the pin numbers are incorrect and the transistor is connected correctly (usually, pin numbers are counted in counter-clockwise direction around the package, however here it is 1-2-4-3). Best Regards, Arne -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/53D3A8A5.5010002%40blinkenarea.org. For more options, visit https://groups.google.com/d/optout.
