I just inherited an Aerotech stabilized HeNe laser, model100A, vintage
1996. The laser power supply is included (RED/BLU 12V input /Hi-V
output w/ white Alden connector),but there's no other power supply.
The stabilization "head" has two "connectored" twisted-pair leads (one
GRN/BRN and one RED/BLU) but there are no markings to indicate voltage
or current draw. There is also no LED in the hole marked "Stable/OT"
on the side of the stabilization head.

The laser runs fine with 12V into its RED/BLU leads, so my question is
about the stabilizer. Due to a tight strain-relief I wasn't able to
get the lid all the way off, but from what I can see the GRN/BRN pair
comes from the PC board contacts that would have been used for the
missing "Stable/OT" LED. So, it looks like they are for remotely
sensing the status.

Sam's very thorough Laser FAQ warns about overheating issues with this
stabilizer, so I'm nervous about fooling around with it until I know
what's what. I'm an optics guy without much electronics know-how, but
on Sam's reverse-engineered schematic I see +12, +Vin and +Vref - tho
I don't know enough to make use of that info. It's a good bet that
the RED/BLU is +12V.

I'm hoping someone can confirm this and also tell me (a) what I should
do with the GRN/BRN leads and (b) how to check/set the over-temp
threshold or whatever it takes to protect from overheating.

Thanks!