[ARC5] Cold filament protection

[Robert Eleazer]

For my PRC-25 and two PRC-77's I built rechargeable battery packs using four 18650 lithium batteries.  For the PRC-25 filament power I used an 317 IC regulator, with a switch to turn it off and prevent battery drain.  I did not know about the surge protection feature.  I suppose I could change the 317 circuit to slightly lower the filament voltage.

By the way, the dial light in those sets uses a lower voltage bulb and drives the heck out of it to get enough light.
 
Wayne

  

---
This email has been checked for viruses by AVG.
http://www.avg.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20180317/0e95bb0d/attachment-0001.html>