variac for elect. magnetic chuck????

[DanGraves]

I have a variac with specs as follows: input 120V 50/60HZ output volts 120 or 140 ( with a switch) KVA max 0.7 Amps 5.0
I can get a electric magnetic chuck on e-bay at a good price but needs controller. Will the variac work? I need it for a surface grinder. Thanks.

 

[lazlo]

A magnetic chuck controller provides DC, so you're going to need a rectifier. AC will degauss

Here's an example schematic from the Sanford magnetic chuck controller:

http://www.d-and-d.com/misc/MANUALS/Sanford/REWIRING/REWIRING.pdf

 

[Charles Vestal]

Dan,

I purchased an electromagnetic chuck that did not come with a controller and then ordered one of these http://www.surpluscenter.com/item.asp?item=11-2269&catname=electric a couple small indiactor lights a switch and a pot. The only thing that is annoying with this controller is you have to power up the drive with the speed pot at zero, you have to make sure to turn the pot down before power up or it will not output the DC to the chuck.

115 VAC in and DC out to the chuck. It has been working great for 3 or 4 years.

Take care

Charles

 

[DanGraves]

Thanks guy's. This helps a lot.

 

[Jason Magruder]

I just slapped a rectifier and a switch on my chuck and it seems to work fine.

I'm not sure why you would need to change the voltage?

 

[lazlo]

I'm not sure why you would need to change the voltage?

If you want to dial-down the magnetic clamping force for thin stock.