12v fan connection question

I’ve got a couple of computer fans to install in my fermentation fridge so as to prevent stratification…They are each 12v 0.6w…how do I connect them so as they are controlled by the spark?

The spark itself will not be able to power these. So you want to get a strong enought 12v power-source and hook this up to a SSR which is controlled by the spark.

Thanks @chixxi I feared that might be the case…For now I think I’ll just use a 12v DC mains adapter and have them switched on continuously…

Remember: I think you will need special DC-DC SSR Relais (not DC-AC). Otherwise you could use mechanical relais oder just a MOSFET is enough (like the IRLIZ44N).

Basically you need a 220v to 12v converter (or 120v to 12v depending on where you are from). These are cheap, or you can even use a old pc-power-supply.

If you hook up this converter to the SSR there is no need for a special relais since you are switching the 120/220v AC current before the converter.

I didn’t even bother to mount a second relais since I only use cooling and no heating. So by attaching the converter to the cooling-relais my fans are always on when the fridge is running. I Am quite happy with the results so far.

I’ve just ordered one of these to power the fans…


I’ll switch it on and off manually.

It can double up as a backup power supply for the spark…

I would just run it continuously on low power. Some fans have a speed switch. Alternatively, you could get an adjustable adapter.

They are PWM fans so I’ll just ground the PWM signal input and they will both run at minimum speed.