On Sat, Oct 11, 2003 at 11:19:19AM -0800, Friedel Bruening enlightened
us thusly
> Hi everybody, anybody can tell me something about an 90A810 or 90C810,
> made by ST, but no datasheet available so far I have seen. It's a 14
> pin SMD, pin 4 has +15V and pin 11 -15V, everything else looks like it
> is a LM324, inputs and outputs, would make sense too, but I would like
> to be sure.
>
> It's stuck on a controller borad from "Carrier" (air-conditioning)
> reading the termistor from the motor.
>
Some of these parts are tested for a closer tolerance, then batch
numbered.
I would guess a little steadier than an lm324. Maybe a quad op07. Check
the quiescent current in the device. It might also be a tcl274.
Another trick is to lift and join a '+' and '-' o/p, and put a low
leakage 10uF capacitor on this to ground, and nothing else. pnp
transistors in the i/p will slowly pull them up; If you charge the cap,
npn transistors will slowly draw them down, but fets will stay where
they are put :-D.
HTH
--
With best Regards,
Declan Moriarty.
--
Author: Declan Moriarty
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