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Timer to leave circuit on when switching off - advice needed
Ivan - 8/8/12 at 06:51 AM

Oops - hit wrong key and posted before message was typed.

I have fitted a wideband O2 sensor to my Cobra and unfortunately the only place available means it is sloping the wrong way making it perfect to catch condensation.

I thought that maybe a small timer on it's heater circuit that would come on say a half hour after turning off ignition and then switch off say half an hour later might stop condensation.

Anybody know of a suitable timer and if that idea would work?

[Edited on 8/8/12 by Ivan]

snakebelly - 8/8/12 at 06:58 AM

less than 1 hour more than 1 minute i reckon,
HTH
:-)

mark chandler - 8/8/12 at 07:34 AM

Turbo timer maybe, not expensive although doubt you will get one for 1/2 hour, this seems excessive, a few minutes maximum I would have thought.

loggyboy - 8/8/12 at 08:13 AM

Simple 555 timer circuit from maplin with a wiring digram from tinternet...

britishtrident - 8/8/12 at 08:56 AM

You can find ready made 12v timers on eBay they are very versatile that countdown after an input is switched off.
The time delay can be pre-set with dip switches,
I have seen them use to turn off troublesome SRS warning lights after a 4 second delay.

rusty nuts - 8/8/12 at 09:21 AM

Some cars use a small electric water pump that runs for some time after the engine is switched off, probably controlled by a timer relay , Renault 19 16v springs to mind and I'm sure other cars possibly some Volvo's have them fitted. Might be worth a look?

snakebelly - 8/8/12 at 11:08 AM

actually, despite my tongue in cheek replky i am also interested in this, want to run an aux water pump on a timer when i switch the car off, would this do the job? bit of an electronic numpty so any guidance greatly received:

H-TRONIC ELECTRONIC TIMER RELAY UNIT MODULE 12 V/DC 100 mA 72 x 88 mm BRAND NEW | eBay

snakebelly - 10/10/12 at 12:35 PM

think i found something that will do the job, its avalable here, have one here now just need to test it

https://www.spiyda.com/magento/index.php/vehicle-electronics/other-vehicle-electronics/dual-fan-controller.html

Ivan - 11/10/12 at 11:22 AM

quote:
Originally posted by snakebelly
think i found something that will do the job, its avalable here, have one here now just need to test it

https://www.spiyda.com/magento/index.php/vehicle-electronics/other-vehicle-electronics/dual-fan-controller.html


Thanks for that - neat Idea linking it to engine temperature.