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1381-J replacement for Miller Solar Engine? Answered

I know BEAM robotics have fallen out of style a bit, but I hope someone is still mucking about with them because they are super cool.  I am working on a Miller Solar Engine and trying to find a replacement for the 1381-J voltage trigger. I tried out the DS1817. It was recommended to me by one the technicians at Digi-Key as a replacement for the MN1381-J and on paper it looks like a good swap, but in the circuit it is just not resetting once the voltage drops.  I have it breadboarded and I can stick the 1381 in it and it works perfectly.  When swapped with the DS1817 it triggers once the top voltage is reached, but then never resets (it just drains forever.)  I double-checked the component type to make sure it was just not a miss shipment of the wrong item, but it checks out.  And I tried swapping the DS1817 component out thinking that I just had a dud (or 5) but it does not seem to help.  Any thoughts?

Here are the data sheets on the 2 items.

one bit of weirdness I already figured out is that the 1381 looks like it has a different 1-2-3 pin out sequence at the top of the PDF but it turns out it does not at the bottom.


I need to make a bunch of the miller engines for an installation at the end of this month and the 1381 costs 1.50 each and has to be shipped from Canada (they are a discontinued Panasonic product that is a bit hard to find and not cheap). In terms of time and money it is not a great option, as I have 100 of the DS1817 sitting on my workbench and only 4 of the the 1381. And now I am also just wanting to know what is going wrong as it is driving me crazy....

Ah, I get you.

Sorry, can't help with the trigger, but I'm sure somebody will be able to.

My first thought is; if you have a 1381 that works, why substitute at all?