MTFCA Forum

Is there a way I can quick test coils?

I run across several Model T coils at flea markets and antique shops.
Is there a way to quick test them?

Thanks

Glay ,I got this from a club member .
When the lamp goes on , then I know that the sec . winding is OK .
Toon

John Regan (Fun Projects) had produced & sold a pocket "beeper" tester quite some time ago - I take mine to every swapmeet !

FWIW I've run a 'FACT' (https://www.mtfca.com/phpBB3/viewtopic.php?f=2&t=9072) happily on five AA cells, it'd probably work on four if they were dry cells and not rechargeable. You can make them into quite a small unit.

No doubt you could do similarly with Mike's ECCT (you may need a few more cells, I'm not certain of it's required input voltage?).

Luke.

If I owned a ECCT, I'd expect that it would work wonderfully on setting up a rebuilt coil, but personally, I would not expect a $400 coil tester to be a reasonable substitute for a battery, lightbulb and some masking tape, like Toon's (or a $9 cheap ohmmeter) when I'm wandering through a flea-market or antique shop looking for cores, but that's just me.

If I had a kid that wanted to write to grandma, I'd probably give him a pencil and paper and not rush out to buy a computer and a printer (and grandma will be far more impressed, too).

now, if he wanted to surf for porn, the computer would be just the ticket, but he's still not getting one.

Scott,

Each to their own, and a basic continuity test is indeed better than nothing at all, but it won't tell you much about the 'coil' as a complete system (what's the capacitor like? Do the points work? Does it 'transform'?).

No doubt one could devise a simple tester that'd tell you a bit more than mere continuity but needn't go as far as a full electronic unit - perhaps people could suggest if they have any interest in this and what they might expect from such a thing?

That said a 'FACT' is fairly inexpensive and can be made quite small - and may then be used to properly setup the recently purchased gem. Likewise Mike's unit would do the same and some people may not realise it's likely to work just as well on a few AA's as whatever they would normally power one from. Thus they could choose to make up a small power pack for such occasions, and may be quite happy with the cost.

I've also remembered now that I powered a 'FACT' from a standard 5V 'power bank' several times while I was developing it. There are many of these things available and it'd make quite a neat setup, although some coils may not appreciate the lower voltage.

Luke.

Luke

I get it, but do you normally buy complete rebuilt coils at flea markets and antique stores? You NZ guys have high-class establishments!

as a FACT guy, I'd expect that you were servicing your own coils and not paying the price for someone else to rebuild them

Scott,

We may be talking at cross-purposes here. Originally I was simply mentioning the fact that electronic testers can be easily powered from a portable supply - then expanded that a little following your previous post. I doubt our random second-hand coils are any better than yours, but if you've got the kit, or can make/buy it, why not find out all you can?

Otherwise, in terms of a simple test, as Clay originally asked, I guess four AA cells and a spark gap is all that's really needed to give a rough indication, maybe add a switch for a little sophistication!

Luke.

Here is my version of a coil tester.
It is calibrated to read 1/2 of full scale when it sees 3500 Ohms in the secondary.

I take it to all swap meets.

Wow! How do you field test found induction coils? A $400.00 tester, or a simple continuity tester?

You guys got all hot and bothered quibbling over a little tool that John Reagan built himself for the sole purpose of purchasing coils for rebuilding with the purpose of guaranteeing it had secondary coils that were intact and could be transplanted into new wood boxes with new hardware. As far as electrical calibration of coils that is a whole different story it has nothing to do with the secondary coil tester that Reagan made.

it has nothing to do with the secondary coil tester that Reagan made

and is not testing coils at a flea-market just that?

maybe I'm dense but I thought that was the original question, not how do I check a flea-market coil for operation...

regardless, this thread has gone in 2 different directions, solving two entirely different issues only one of which was the original question...we're very good at that here, so I view it as mission accomplished, without agreeing on what the mission even is.

Just to avoid any confusion from my posts:

I wasn't aware from Clay's original question that he solely wanted to check secondaries? I took the question to mean how to quickly/easily test that a coil (fully) operated, away from one's workshop.

This is the reason I was talking about using AA cells etc to power a comprehensive tester - in order to make it portable. Said tester could then be easily carried to wherever the coil was...

Luke.

I read the initial posts, that it was a function like the beeper (CT-2) John did. You are on a flea market and stumple over a pile of coils and just wants the rebuildable ones.
I do rebuilding coils in Europe and asks customers to meassure the resistance across the two terminals to be 3000 - 3500 ohms with a multimeter/ohmmeter before they send them to me. You can have a multimeter in your pocket, but the CT-2 I use myself when browsing for coils.

Don't get your *#@% 's in a knot boys, after all this the GENERAL DISCUSSION section of the MTFCA Forum and this is we all learn the goodies of the Model T and how it works. After fiddling with 'T' electricals as an Electrical Apprentice from 1956 and owning T's since 1964, I try and learn something about them everyday and this the best place. Grow--Up....n

Neil

when I get a lecture from you, I know that I must have made a difference in the world that day

chill, dude

it's all good