EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: Infrared_Fred on November 24, 2021, 02:47:32 pm
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Hello!
About a year ago I ordered a large box of vintage LED displays from someone on Ebay and included among assorted displays were two nearly identical circuit assemblies that appear to be some sort of panel meter. The assortment of displays included a single unused (or else previously socketed) TIL306 (http://www.decadecounter.com/vta/articleview.php?item=319) LED display, which is a seven segment LED display + IC counter + decoder and two circuit boards that had identical looking displays to the unattached one, other than dirt and gunk on them. It is also possible that they are a TIL308/309 (http://www.decadecounter.com/vta/articleview.php?item=1171) but....whatever. The circuit boards have the digits in a +-3.5 digit format with three integrated displays and one passive +-1 overflow display. ICs visible on the front board are 2x 555 timers and a 7474 D-Flip Flop, which I am pretty sure goes with the overflow display based on TI schematics I have read. There is a second board with a bunch of ICs, but the only part numbers I can read are a LM308 precison op-amp since they are on the inner side of the circuit board. There also is a precision 10 or 25 turn potentiometer most likely for calibration. There does not appear to be any manufacturer's logo or identification, although there is a rather difficult to read 62?44A and Made in USA printed on it. Googling the 62?44A with various numbers for the unreadable one only gave real estate listings or other useless results. If they are panel meters I am much interseted in using them as is, but for that I would need a pinout or such information, since none marked on the device itself. I could take them apart but I wanted to ask here for identification help before I did that since I am a newbie and I don't want to damage them. Hopefully the pictures below are helpful--please let me know if they are readbale or if you want any differnet angles or anything like that. Thank you so much for you time and your help!
Note: I am reposting to this forum since it occurred to me that this might be a more approriate place for this than general projects.
Minor update: I tried a google picture search (as in using the images posted below itself and Google's AI identification) and unsuprisingly it yielded no useful results; it identifies it as a "hardware programmer" which it defenitely is not.