On Sun, 10 Sep 2006 12:18:58 GMT, "Farticus"
wrote:

Thanks for the assistance John. I think I've fallen into the trap of using a
crappy breadboard thus resulting in sloppy connections ending up with a
sagging supply voltage. The bench supply is more than adequate and well
regulated.

I have been playing with a protection circuit that I need to develop to
protect FET's used as output devices.
I want to have their drive circuit turn them off when a certain current is
reached to protect them etc.

The source to the comparator is derived as below:


(+)--------------------------------------------------------|

|

[LOAD]
Source ---------------------- |

__|
---||
__ FET

|

|
(-)---------------------------------------------------------|

NOTE: There is no limiting resistor in the FET circuit, so it is vunerable
to short circuiting.

There are 8 FET's driven from PORTB of a micro. I want to use the signal
from the comparator to feed back to the micro to turn the offending port bit
off, and use another output port to indicate the fault.

Hopefully once I get rid of the crap breadboard the problem will go with it.

---
I can't understand your drawing. That is, it looks like you used
tabs instead of spaces and nothing lines up.

Also, if you bottom post it makes it a lot easier to chronologically
follow the thread.

Thanks,



--
John Fields
Professional Circuit Designer