The Secret Society of Lathe Trolls

catch · Joined: 01 Jun 2006 Posts: 9

hi i just recently brought a presto k8 recorder which is 110v and has a usa plug ive got a convertor 110 - 240 50va and the recorder powers up fine and all works but after about 5-10 mins it cuts off and my transformer seems to get very hot now i presume this is the transformer im using and its not powerfull anough for the recorder. just wondering anyones views on this and what sort of convertor i could use to power this recorder properly?

cuttercollector · Joined: 11 Jun 2006 Posts: 307 Location: San Jose, CA

You are using a US spec. machine on 220V / 50hz right?
You need a stepdown transformer with greater wattage capacity than the Presto draws. There should be an indication of the total wattage needed by the motor and amp somewhere on the unit. Probably somewhere between 100 - 200 watts. Your present transformer is too small. It needs to be over by at least 10%, preferably more.
Next issue, your turntable is going to run slow. You are running on 50Hz so the motor will run slower than on 60Hz US. You will probably need to have a new slightly lareger spindle machined for the motor.

andybee · Joined: 14 Aug 2006 Posts: 65

I had the same problem, I have a lyrec motor 110v/60hz, but here in germany is 220v 50hz.
I solved the problem with a siemens micromaster motor controller box.
I makes a nice 110v 60hz out of 220v Smile

best thing: Halfspeed is easy, you can program several motor Hz and store it in memory Smile

tsullivan · Joined: 02 Jul 2006 Posts: 27

Another issue is that if you run a motor designed for 60 hz on 50 hz, it will run hotter because of the reduced inductance at 50 hz.

I was wondering, how much is that power supply that will put out a different frequency? I am guessing that it must rectify the 50 hz to DC, then invert it back to 60 hz AC, probably an expensive and not very efficient way to go.

Tom