UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Single phase ex-avionics motor start up?!

Argus25 · 12th Feb 2018, 2:10 am

I don't think a lot of these small fans ever get to synchronous speed, even on full voltage but I have never put a strobe on one to find out. I was surprised how smoothly they slowed down when reducing the voltage, but ideally at least for the three phase types the frequency would be controlled to alter the speed.

I found that one quick way to make an avionics three phase power supply was using a motor VFD, but it needs a good sinewave filter

http://worldphaco.com/uploads/3phase.pdf

Al,

There are quite a few low power single phase 12 or 24V DC to 115V 400Hz inverters for aircraft instrument use that would run your fan. Search "Static Inverter". To give you an example of these sorts of things here is one type ( please excuse the ebay reference):

https://www.ebay.com/itm/New-Arnold-...IAAOSwA3dYkmDd

Unfortunately a lot of these sorts of parts are expensive as they are for aircraft.

12th Feb 2018, 2:10 am	#12
Argus25 No Longer a Member Join Date: Oct 2016 Location: Maroochydore, Queensland, Australia. Posts: 2,679	Re: Single phase ex-avionics motor start up?! I don't think a lot of these small fans ever get to synchronous speed, even on full voltage but I have never put a strobe on one to find out. I was surprised how smoothly they slowed down when reducing the voltage, but ideally at least for the three phase types the frequency would be controlled to alter the speed. I found that one quick way to make an avionics three phase power supply was using a motor VFD, but it needs a good sinewave filter http://worldphaco.com/uploads/3phase.pdf Al, There are quite a few low power single phase 12 or 24V DC to 115V 400Hz inverters for aircraft instrument use that would run your fan. Search "Static Inverter". To give you an example of these sorts of things here is one type ( please excuse the ebay reference): https://www.ebay.com/itm/New-Arnold-...IAAOSwA3dYkmDd Unfortunately a lot of these sorts of parts are expensive as they are for aircraft.