Old module marked 3100 B5

I have an ~40 year old circuit card that has what I believe is a thyristor 3 part on it. The part has the following marking 3100 Mex B5 and the package looks to be maybe a T0-220. I am trying to find a replacement or the spec?


Welcome to the Digi-Key Forum. The only thing I keep finding is the Littelfuse series that has the 3100 in the part number. I do not see that there is the TO-220 anymore. Though here is the link to products on our website: https://www.digikey.com/short/wf0fbbtp . I am not sure if this would be the same, but this is all I find when I look up 3100 and thyristor on the Internet. It is really hard to say on a 40 year old product. This is what my searches keep pulling up.

Thank you Verna, yes that is all I found to. Any other ideas to confirm or get a spec

That’s an old Teccor part, almost certainly a triac of some kind. No less than 400v rating assuming 120VAC operation, current rating no less than that given for the device as a whole. Teccor got bought out close to 20 years ago, so chances of finding a product catalog are slim.

if I had to guess, I’d say the two switches determine whether one gets the top half of the AC waveform, the bottom half, or both.

Thank you Rick, do you have any suggestions as a replacement part?

None that I could suggest confidently based on currently available information, though this would be a ballpark that seems plausible to me on a total guess basis.

Some triacs with metal tab are internally isolated; check whether this is or should be the case based on potential for people/conductive things to touch whatever that tab is fastened to. This would be another important piece of info for making a selection.

I think I may be of assistance here. I have several of these controls that are also inoperable. I’ve been able to confirm that the 3100 Mex triac is the culprit by moving a known good one to an inoperable circuit board. I was able to locate another control that had a different triac in place of this one, labeled MAC228A6FP. While I can find a datasheet for this component I am unable to find any for sale. Do you have a suitable replacement for the MAC228A6FP? Thank you for your help.

Here is the datasheet for your MAC228A6FP

For a replacement, try the Littelfuse MAC228A6G. It seems to have about the same specs as the old Freescale alternate you found. As a bonus, it appears to be relatively inexpensive and it’s available here on Digikey!

Thank you Karl. After further investigation I found the TRIAC was ok and fixed the switch unit by swapping 2 of the toggle switches.