UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - 1940's industrial desk top table fan help needed

TonyDuell · 16th Sep 2019, 2:28 pm

I took the markings to mean 110V DC too.

A wound-field commutator motor (which this looks to be) might be 'universal' (runs on AC or DC) or not. If it's shunt-wound (field coils in parallel with the armature) then it will be DC only. If it's series-wound then the field core can be solid for a DC motor but has to be laminated for an AC (or universal) one. Until the motor is in bits we can't know.

I noticed the missing brush cap (and brush?) too. It is worth pointing out that the the brush holder/brush will be live when the motor is in use, so the cap has to be an insulator. The chances of finding the original are close to zero, a cap could be made on a small lathe, but do you have one?

It's the sort of thing that I would be preparted to fiddle around with _for my own use_ and not use it for very long at a time or leave it unattended. I could probably come up with a suitable power supply based on an double wound transformer and rectifier diodes, and I would know (I hope) the risks and what to watch for. Even then I wouldn't trust it to be run without a technical person present. I certainly wouldn't consider restoring this for somebody else.

16th Sep 2019, 2:28 pm	#9
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,220	Re: 1940's industrial desk top table fan help needed I took the markings to mean 110V DC too. A wound-field commutator motor (which this looks to be) might be 'universal' (runs on AC or DC) or not. If it's shunt-wound (field coils in parallel with the armature) then it will be DC only. If it's series-wound then the field core can be solid for a DC motor but has to be laminated for an AC (or universal) one. Until the motor is in bits we can't know. I noticed the missing brush cap (and brush?) too. It is worth pointing out that the the brush holder/brush will be live when the motor is in use, so the cap has to be an insulator. The chances of finding the original are close to zero, a cap could be made on a small lathe, but do you have one? It's the sort of thing that I would be preparted to fiddle around with _for my own use_ and not use it for very long at a time or leave it unattended. I could probably come up with a suitable power supply based on an double wound transformer and rectifier diodes, and I would know (I hope) the risks and what to watch for. Even then I wouldn't trust it to be run without a technical person present. I certainly wouldn't consider restoring this for somebody else.