> The fact that 12V still shows on the far side of the amplifying circuit tells > me that a short is occurring between the input power side and the output > (after replacing it, I do not think the new IRFD220 chip is nonfunctional, > nor the capacitors/resistors accompanying it). This is good, since it > appears there are very few 12V elements in the circuit, the rest being either > 5V or high voltage. Narrows down the possibilities. According to the > diagram, the UF4004 diode (D5) is the primary element separating the 220V > output of the MOSFET from the 12V input
Nope, the 12V will flow right through the diode if the rest of the circuit is non-functioning, so you’ll see the 12V input at the output as well. When the circuit is functioning, the FET pulls current through the inductor, then suddenly switches it off, and inductive kickback produces a high voltage spike which is then rectified and filtered to become the HV output. If the FET never turns on, you’ll see 12V at the output. If the FET never turns off, the inductor and FET will get hot and you’ll see almost zero volts at the output. If the FET turns on and off as it should, you should get HV. - John -- 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/05D1B239-6D36-4262-B08E-4C899CFCCC99%40mac.com. For more options, visit https://groups.google.com/d/optout.
