Ron, William and Carl, Thanks! I didn't even think about a UPS (KIS,S!). That might be the easiest solution, and the little UPS that Carl suggested looks like it would work. I guess I would like to try a circuit first - maybe I could learn something. I found a couple of designs that give a 1pps output. I figured I could switch on a transistor with the clock's 5V supply that would conduct the 9VAC to the PIC, then switch another transistor that would open the ground connection to the battery powered circuit. When the 9V goes away, the 1pps signal would then turn on, and be sent to the PIC through a diode. Is this a crazy idea? There are details to work out...
Thanks again, Jim On Wednesday, September 5, 2018 at 8:50:55 AM UTC-6, Jim KO5V wrote: > > Hi everyone, > > I have several nixie clocks, including two clocks that I built about 12 > years ago that use the mains frequency for timing. I live in a semi-rural > area, and during this time of year, I lose power quite frequently due to > lightning strikes. This can be just a "blip", or it may last several hours. > Either way, I have to reset each clock. Both clocks run off of 9VAC > wall-warts. > > All I want to do is to keep the logic alive during an outage. My guess is > that this is more than just adding in a circuit with a battery - a > frequency source may also be needed. Looking at the schematic for the kit, > the 9VAC is split - one branch goes to a pin on the processor, and the > other to the rectifier and 5V regulator. I'm thinking there might be a way > to use some kind of an or-gate to select either the wall-wart, or the "keep > alive" circuit. Here is an example of where my lack of electronics > experience really shows, but I can build from and sometimes even understand > a schematic. > > So, if anybody has ideas or experience, please let me know. I've looked at > several circuits on the web, and have a vague idea of what can be done. > > Any suggestions will be greatly appreciated! Thanks in advance, > > Jim > -- 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/e7795e7b-0363-456a-8e23-7579e65519b4%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
