Hello

I am looking for the schematic for Omron H3CR-H8L timer relay.
Has anybody reverse-engineered this or similar units?

Tks
MartyK

 

looking for the schematic for Omron H3CR-H8L timer relay

Hi, is it okay to ask why? Looking at the datasheet it's from 2010 and whilst the block diagram gives a fair idea of how it works you probably wouldn't do it the same way 22 years later. They aren't that expensive to buy so replacing a broken one in an otherwise functioning control system is probably the safest simplest option but if it's just set at one delay time and the exact accuracy is not so important a simple analog circuit would probably do the job. You could do all sorts of tricks if you use a processor.

 

Hi Jerry

I don't know where you live, but here in Canada it is a VERY expensive unit ($186).
The problem is it is not releasing.

 

2022-2010=12

The problem is it is not releasing.

I would start the list of likely causes with "relay contacts welded shut."
Does it ever open? Like if you leave it unpowered for hours and come back, the contacts are still closed? If so, I would open it up and replace the PCB-mount relay that I assume is inside.

 

2022-2010=12

The relay is in top shape. It is a bi-stable device which only needs a pulse to close and a pulse to open.
The unit will work ok for months and then just stay closed. I assume the opening pulse never happened.
It is something in the control cct: pulse too short?
I guess nobody has reverse-engineered this timer.