Trip amplifier / Threshold detector at 70C

[DavidnLee]

Hi
I am after a suitable sub-assembly to detect a 0-7V signal being below 0.5V. There are many available, but my problem is that the ambient temperature may exceed 70C, and any that I have found are only rated to 50 or 60C. I expect they use 70C internal components, and need the margin. Anyone know of any high temperature variants?

Suppliers I have found, which do not appear to cover this temperature include PR electronics, Brodersen, SIL, and Instrotek

 

[OperaHouse]

The typical problem is that most of these devices have electrolytic capacitors that are rated at 80C. Even at that temperature, they have a rather limited life. Relays would also have to be derated to operate at that temperature. There is no reason a unit can not be designed for this temperature. I've often run tests at this temperature on electronic modules. While this temperature is not exotic, this is beyond what manufacturers usually design for. The question is, do you have any quantity.

Problems are technical.
Solutions are political.

 

[DavidnLee]

Fairly low quanity - 30 off only.

 

[cbarn24050]

There are numerous micro devices that work in the automotive temp range -40 to +85. Otherwise the military option to +125 can be had at a price.

 

[OperaHouse]

Next questions are:
What is the supply voltage
Does it have to switch any signifigant output
Can it be open board or must have a case
Are any agency approvals required
Is this temperature always there or just sometimes
What do you expect the service life to be

I know of three products that would work and the company has a history of modifying in those quantities.

 

[DavidnLee]

The answers to your queries:

What is the supply voltage? 24V DC
Does it have to switch any signifigant output? No - 100mA typically
Can it be open board or must have a case? Open board preferred
Are any agency approvals required? Use by UK navy on ship
Is this temperature always there or just sometimes? Just sometimes.
What do you expect the service life to be? 20 years

Thanks