Hi,

I am trying to work out exactly what this timer is functioning as, it is part of a CPU reset circuit. Pin 7 is not connected so I cannot work out how the C1 discharges, in normal operation when power is applied 5v is present and 12Vdc is present on terminal H3 which operates the relay. The function of terminal F15 is unkown.

Could somebody shed some light onto what's going on please, is it monostable, astable or other?

Thanks
Dan

 

It looks to me it is functioning as a 5 volt watchdog reset.

 

Could you elaborate more please?