That's a good point. I was a bit surprised that the transistor said "A42" and not "MPSA42", as it should. Perhaps it's a 2SA42!
The MPS series was started by Motorola, which is no longer in the component business. On Sat, Feb 9, 2019, 11:10 AM GastonP <ghpic...@gmail.com wrote: > Did you verify that you verified that the layout is E-B-C? Or is it B-C-E? > > On Friday, February 8, 2019 at 9:35:14 PM UTC-3, Thomas Kummer wrote: >> >> My understanding is that a MPSA42 is an NPN transistor and the MPSA92 is >> a PNP. My understanding of how an NPN transistor works is that when the >> base “P” is turned on the circuit from collector to emitter is shorted. >> When the base is off the circuit is open. I’m trying to use the decimal >> point on a Nixie tube rather than an LED for the alarm. So, I have the >> collector hooked to the tube the emitter hooked to the ground, and the base >> hooked to 5V signal, I also have a 10K resistor between base and 5V. >> However, no matter what the decimal point stays lit!! Even when the signal >> is off. The only time it isn’t lit is if the base is open, if I even touch >> the base the decimal point lights up!! The transistor has the the imprint >> A42 B331. It appears to be a knock off and that could be where my problems >> are coming from. I’ve tried looking for a datasheet, but to no avail. Any >> help would be appreciated. > > -- > 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 neonixie-l+unsubscr...@googlegroups.com. > To post to this group, send email to neonixie-l@googlegroups.com. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/547f3d40-7c96-42a2-9306-b745f558b3a0%40googlegroups.com > <https://groups.google.com/d/msgid/neonixie-l/547f3d40-7c96-42a2-9306-b745f558b3a0%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- 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 neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/CAPbqtvcBzaDT%3Df4dH%2BKS0NwtjPEcJ-OD9uxRbzzc3tSxoQPmqA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
