Device Identification Assistance - Page 1
Forum section: electronics / general

author: German Ron
author_rank: Newbie
timestamp: February 14, 2021, 02:40:16 pm
content: Hi,I discovered a few of these in a bag of junk a colleague of mine gave me when he retired some 20 years ago.They're a strange package, which I don't recognise, and I'm curious to know what this package is too.They appear to be marked 6-5910 / ECC 074. I don't think they're a valve though.Any ideas?Thanks very much

author: jmelson
author_rank: Super Contributor
timestamp: February 14, 2021, 05:10:49 pm
content: Quote from: German Ron on February 14, 2021, 02:40:16 pmThey are almoist certainly a dual rectifier in a press-fit package, that has been pressed into a TO-3 adaptor. And, likely, about 40 years old.Jon

author: Benta
author_rank: Super Contributor
timestamp: February 14, 2021, 05:51:10 pm
content: Quote from: jmelson on February 14, 2021, 05:10:49 pmMore likely a three-phase rectifier for an automotive alternator exciter. And most certainly more like 50 or 60 years old.

author: bob91343
author_rank: Super Contributor
timestamp: February 14, 2021, 06:26:30 pm
content: Could also be an SCR. Put it on one of those Chinese all purpose little testers.

author: Benta
author_rank: Super Contributor
timestamp: February 14, 2021, 06:52:22 pm
content: Quote from: bob91343 on February 14, 2021, 06:26:30 pmA possibility I also thought of, but the fact that the three terminals are the same size led me to reject it. All SCRs I've seen in this style have a small terminal for the gate.Press fit was popular in automotive designs back then, with the case being one terminal. This would mean that an SCR would have one large terminal and one small.The OP should use a diode tester on it at least. That might bring illumination.

author: nctnico
author_rank: Super Contributor
timestamp: February 14, 2021, 11:32:28 pm
content: Quote from: bob91343 on February 14, 2021, 06:26:30 pmSCRs in this package style usually have a smaller terminal from the gate. Just checked my parts bin

author: amyk
author_rank: Super Contributor
timestamp: February 15, 2021, 04:00:21 am
content: 1970s/80s power semiconductor databooks might yield a clue... although the modern RD91 package triacs look similar.

author: German Ron
author_rank: Newbie
timestamp: February 15, 2021, 09:11:43 am
content: OK, I've ordered a Chinese component tester.I've also taken a larger handful out of the bag. They're all marked 6-5910, some are marked ECC343 instead of ECC074. There's no marking on the mounting flanges which would indicate they'd ever been used.The case does not conduct to any of the pins (or at least at multimeter voltages). They conduct in both directions from 1-3, but 2 doesn't show any conductivity to 1,3 or case in either polarity.I'm very intrigued as to who made them, there's no manufacturer's logo on any of them.Thanks for the suggestions thus far.

author: German Ron
author_rank: Newbie
timestamp: February 22, 2021, 10:43:40 am
content: OK, out of the 8 I took out of the bag initially, none of them actually worked.Turns out they're NPN power transistors. Both part codes look the same on the Chinese tester. Most of them appear to be dead, with various resistances as shown in nok below.I'm still interested as to who made them etc, googling the part codes doesn't give me anything at all useful. I expect that my curiosity in this case will have to remain unsatisfied.

author: Gyro
author_rank: Super Contributor
timestamp: February 22, 2021, 12:37:24 pm
content: From the readings, they look like Germanium power transistors. They may all be functional - Germanium would tend to have higher leakage currents, which can easily fool simple semiconductor testers. Try putting them in the fridge and testing them cold (cold = lower leakage).