Kenlowe fan as a generator?

I have the same setup in my Spit - the switch is the one Kenlowe supply with the built in light. I've also noticed this but thought little of it. I must check your theory out too.

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Yes Kenlowe used to mention this effect in their instralltion leaflet, but I've had mine for for 20 years so I've no idea if they do now. Electric motors are quite efficient as generators.

Martyn

Thanks for the reassurance Martyn and Doug. I'll stop worrying about it then! Although I only fitted the fan recently, it was secondhand so came without a leaflet.

A good few years ago I had a similar but more catastrophic 'role reversal' of electrical components in a Series 2 Landrover. Something nasty happened in the voltage regulator department which tried to turn the dynamo into a motor. However, the dynamo wasn't too happy trying to turn the engine via the fan belt and it got rather hot and smokey!

Simon H

Absolutely. Any DC motor will act as a generator too. And the reverse. An alternator won't because of the diodes. But a three phase electric motor will also generate three phase AC if driven.

The efficiencies tend to suffer though if you reverse things since they need optimising for each function. Hence combined starter/dynamos being still rare on other than small engines.

Not all of them, including some late model Kenlowes and other recent cooling fans.

If you have a "brushless" motor it uses a solid-state Hall-effect switch to act as a commutator. These won't work as generators. Their advantages are low noise and long-life, hence their use in computer fans. They also offer some flexibility in arranging the bits inside, so many ultra-thin "pancake" motors are brushless too. This includes many radiator fans intended for narrow spaces and I think the thinnest Kenlowe is of this type.

I suspect it is generating electricity and illuminating the lamp. The switch, with only 12 volts across it, it unlikely to be "tracking" across the insulation.

Pete

Right. I've come across these motors on various things - like late incarnations of analogue tape recorders, but didn't realise they'd filtered down to car use on something as basic as a fan motor.

Trust you to complicate the issue. ;-)