Joule Thief

[TinselKoala]

Ah, Triplett. I have a Simpson (somewhere) that is practically identical, same HV input locations and all but now that I see the full view I can tell that the Triplett is not quite as "boxy" as the Simpson. The meter faces are nearly identical too. Google Images has some great pix of both types.

[Pirate88179]

I actually thought my Dad had a Simpson, and was surprised to find out it was a Triplett.  I asked a friend of mine the other day if he thought that a meter he bought this year would still be working 59 years later, and he said ....no.

I had a lot of fun making it work again and I love the idea of using something that is older than I am. (Not by much)

Bill

[TinselKoala]

I have a Fluke 83 DMM that I bought in 1983, I think. I use it every day, and I'll bet it will outlive me. The display has one of those weird rubber-metal contact strips, and every once in a while I have to clean it and re-seat it so the display segments will all work well, but other than that it still does great. It uses these big cartridge fuses, and those are actually still available too. My local supplier is the regional Fluke dealer, too, and he's got all the Fluke goodies in stock. Wanna pay ten dollars for an alligator clip? If it works...it's a Fluke.

[Pirate88179]

Does your Simpson utilize that funky 30 volt battery that is no longer available?  (That is why I had to do the battery hack in the video)  If so, what was your workaround for that?  (Knowing you, you probably have spares stashed away somewhere, ha ha)

I have an old Omega DMM (Model 881C) from around 1988 or so.  Geeze, I better open that one up and check the battery condition, it might be a mess in there as I have not used it for a very long time.

Bill

[SeaMonkey]

Pirate88179,

Do you have any idea what the current draw from
the 30 Volt battery might be?

If it is only a few milliAmperes it would be possible
to make a DC to DC Boost circuit to transform a
low two cell voltage to the needed 30 Volts with
pretty good regulation.

Do you remember the TI Scientific Calculators
from the '80s (TI-30) which were powered by either
a 9 Volt battery or the rechargeable 2-cell
NiCd boost replacement?