[planeflier]

I have just purchased (3) new 36 VDC servo motors to upgrade my router table from steppers. I have just purchased Gecko 320's to drive my servos. I need to build a DC power supply to power my servos. I need some help sizing the correct transformer. I found a 35+35v volt 600 or 700VA toroidal transformer. Will this be large enough to power my servos? The current rating on the servos is rated 2.4 amps from the specification sheet. Where is a good place to purchase a rectifier and capacitors to complete the power supply to DC?

Any help would be greatly appreciated. My electronics memory is a bit (chair) rusty! What would be a easy way to tap off of the DC side to get my 5v required to drive the breakout board and Gecko’s?

Thanks in advance
:cheers:
Planeflier

[Al_The_Man]

That size should be plenty, the most efficient way with a toroidal is to put a few turns of enamel wire on create a 5v winding, wire and componet size need not be great as the 5v demand is probally not that large anyway.
Any of the supply houses such as Digikey, Newark, Mouser etc for parts.
Al.

[planeflier]

Al,

Can you elaborate on how to wind for the 5 volts? efficient way with a toroidal is to put a few turns of enamel wire on create a 5v winding, wire and componet size need not be great as the 5v demand is probally not that large anyway.

what size wire etc, as I have never done anything like this.

[Al_The_Man]

Go to your local motor winding shop and get them to sell you a 10ft or so of 18~20g enamel wire, You will need to know the turns/volt of the Toroid, one way is to wind on 10 turns, bare the ends, power up the transformer and measure the AC as close as possible, this allows you to calculate the turns/volt, you will need ~4vac for 5vDC, allowing drop for the bridge.
Take the necessary turns off after calculation and tape the winding to the core.
All you need now is to obtain a small bridge rect. and capacitor ~500µfd.
And your done.
I assume you just want the 5v for low current logic?
I find the need to tailor Toroids all the time as it is hard to get one with just the right specs sometimes.
Al.

[planeflier]

Thanks for the help Al I will do that later this week.

[unterhaus]

Al, does he really want 50v dc for a 36v servo? I suppose it probably isn't going to hurt anything.

[smarbaga]

in reguards to the 5 volt winding.
you don't need to remove any of the existing mylar wrap, just wind the wire over
the transformer as it is and then put some black electric tape over the added wire. pull out a length of the electric tape and rewind it into a small roll so it can pass through the toroid hole.