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CDI electronic indicator (ancient) - pin outs?

aribert

Cast Iron
Joined
Jul 2, 2008
Location
Metro Detroit, MI
Not sure if the subject I have a question about should go in this subforum or in the Antique subforum. I bought some DTIs and calipers as an auction lot. Along with it came a CDI electronic indicator. Its so old is has neither a model number nor a bar code on the box (guessing it might be one of the earliest electronic indicators they made - mid/late '80s?). I see no battery access. I'm guessing it has an internal rechargeable Nicad battery. I'd like to play with it - does anyone know the pin outs (and voltage, I have no intention to save any data). Images attached for indicator description.
 

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Figured I would bump the thread once before tossing the indicator. So if you know the pin outs (for voltage in - don't need any data collection). Just trying to play with it before scrapping it.
 
Here's an idea: use an ohmmeter. Likely, the case is grounded. The pin that's shorted to the case is therefore ground. Then find the pin with the lowest (but not zero) resistance to ground; that's power.

There is risk, but as long as you probe the pins with the positive terminal of your ohmmeter, you are not likely to damage anything. Use the lowest ohm range on your ohmmeter or multimeter.
 
SeeFair:
Thank you for the response - minimal risk to me since if I can't play with it, it will go in the trash anyway. I'll try out your suggestion in the next few days. I did find documentation for a later version indicator with a completely different plug and the input voltage was 5 Vdc so I expect that this indicator will use the same voltage.
 
I have a VERY distinct memory from the late 1980s or early '90s, of this type of CDI digital indicators not taking accepting charges, and not working when connected to the chargers. The indicators had come out of the Cal Lab on Friday afternoon, to be used that night for a very important customer-witnessed test.

Out of desperation, we broke the Cal Lab seals on one of the indicators, removed the indicator back, and found that the cells were "button cells" in spring holders. One of my associates raced to an all-night drugstore, and bought them out of a hearing aid battery that would fit into the indicator cell holders.

The indicators worked with the hearing aid batteries, and we got through the test after adding before-and-after-test verification of indicator accuracy on gage blocks.

Funny thing, the customer rep was favorably impressed with our "improvisation engineering", but our Cal Lab was madder than heck.
 








 
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