[Cyclone]

Hello all, maybe you can advice me on this one....just received a toroidal transformer I bought from ebay....it measures 6 inches accross and 2 1/2 inches high
label says:
Made by AMVECO Magnetics USA TRF#2626-RP2S1K
PRIM. 0-100-120V 50/60HZ 641VA
SEC. 120V 5A

Can I use this to run 3 geckos 201 in my project router?
is the secondary voltage too high?
it was only 15 dollars with 3 minutes to go (no time to research) so I bought it anyways. It is brand new still in the box.

The steppers I am looking at are 270oz running 3.75V at 2.8 amps

Thanks in advance

[Al_The_Man]

You could always take the secondary off and rewind with heavier gauge for 50v at 12 amps, if you only need 5amps then just take turns off.
Al

[Cyclone]

Thanks Al for the quick reply. I have one more question, before I start to unwind this thing and permanently turn it into an unusual paperweight, this transformer has 8 leads two individual red and green wires (circuit 1) and six other wires bundled with plastic shielding that includes 2 blues, 1 brown (circuit 2) / 1 white, 1 black, 1 yellow (circuit 3) am I guessing right to say that the green and red are the primaries? and that the other two circuits could give me different votage outputs? I want to put power to it and measure actual voltage and I do not want to connect it wrong and blow the thing up. I cant find any color codes that match on their website. The green and red leads are wired to a white plug, the others have small spade connectors.
Thanks!

[Al_The_Man]

My guess would be the two with the plug may be the primary, but I would first compare the resistance of that winding with the white,black,yellow they could also be the the primary, made for 120,230v
The 2 blues 1brown I would say are a centre tapped secondary.
If you accidentaly hook it up to a high voltage secondary, no damage may occur, but it may give you chance to check the voltages. The primary is usually the first winding (inner) on the transformer.
Al

[ViperTX]

Look at the side of the Toroid, it should have a label indicating which are the primary wires, looks like you have a tap for 100 and one for 120 on the primary side. Also if you look closely the primary windings are usually wound first and are the deepest windings. Use an ohm meter and measure continuity.

[Cyclone]

You guys are good!..... No really you are good!

Sent an email to Amveko yesterday to ask them if they could provide me with lead schematic their reply:

This unit is a custom made transformer for one of our customers. As the design is proprietary, we are unable to release information about this unit without their written consent.

Read the posts to my question and the toroid has no label. So armed with a razor I started to cut at the plastic wrap to find that the green and red ARE the secondary and the other leads are the primaries.
"so lets re-wrap it" one problem I encountered was a poured epoxy hub hmmmm maybe I can drill around the edge and slowly break it off....after I cut all the plastic wrap the epoxy hub just pushed right out! Wow things are never this easy for me....so I start to unwrap....4 feet= 2Volt drop... 4 more feet...10 feet.....one wrap all around and still at 80 volts took off nearly 3/4 of the wraps and I am at 51.2 volts!!!!!!! I did a small dance :banana: and I guess I have a 50v 5amp transformer??? this was too easy!

Thanks Al and Viper!
so Al if I want to bump up the amps I just unwrap the rest, measure the lenght of what I have, and re-wrap it with heavier coil wire? (the wire that is in there now is .058 in)


Thanks again guys!

[Al_The_Man]

so Al if I want to bump up the amps I just unwrap the rest, measure the lenght of what I have, and re-wrap it with heavier coil wire? (the wire that is in there now is .058 in)

Thats close to 16 gauge so you probabally could get away with close to 10amps
If you want heavier then, yes you will have to rewind the secondary.
What about the 2 blues and brown? and the what did the green and red turn out to be?
It sounded like you had two secondaries.
Al

[Cyclone]

The blues and brown give me 120V
the yellow and blues 100V
the Yellow and Brown 19v

The red and green were the secondaries (outside wraps) The rest I am guessing are two primaries? 0-100V and 0-120V??? custom transformer that would give different outputs with different inputs? I do not know. I do know one thing....I am very happy now! lol
I used the white and black for input and red and green is my output. One more question if you dont mind.... if each motor uses 3 amps and I use three motors I will need a minimum 9amps supply?

Thanks again Al!

[Al_The_Man]

This is a rough guide for calculating the required AC secondary for a DC output and approx current.
For a full Wave Bridge.
VAC = 0.8 x (VDC + 2)
IAC = 1.8 x IDC
Al