I think I have drawn it wrong.  Bases should be connected to collectors in
both NPN and PNP.  re-analysing ....



On 4 September 2016 at 20:36, Justin Richards <justin.richards@gmail.com>
wrote:

> Trying to repair Amp and understand how the thermal cutout works.
>
> The circuit employs a thermal switch that is N.O.
>
> It is connected to the base of an NPN and PNP in series.
>
> Attached is image of a circuit that hopefully captures the essence of the
> real circuit. I hope that I have not missed anything too important.
>
> I have tried to analyse in LTspice but the voltage levels around the
> circuit remain unchanged regardless of the state of the switch.
>
> I assume the idea is that the balanced input signal is clamped when the
> thermal switch closes.
>
> Hoping someone may be familiar with this approach and help explain how it
> is intended to work.
>
> Justin
>
--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.