Thread: Toroid transformer no ouput
Have a read throught this http://www.mycncuk.com/threads/9268-...se-Spindle-VFD. Message #46 gives a good diagram for all the electrics and shows where to put fuses or MCB's. One nice thing about the UK is we have fuses in our mains plugs, so if something goes wrong there is generally a fuse that will blow before any major damage is caused.
Because you are using a torroidal transformer, the inrush current (how much current is taken when you first apply mains power) can be many times the rated current of your transformer. You may have to use a bigger fuse than you think, but also be carefull to not go too far as you could cause damage if you do get a short.
Can I also make a suggestion to you. The wires from the transformer to the rectifier and to the capacitors should be much shorter and more heavy duty - at least the same wire size as the transformer wires.
For info here was my power supply build. Bit late now (!) but you can see the colour coding on the transformer, plus I also noted higher gauge wires on the secondary which I matched. Remembering back to my school days when the transformer coil drops the voltage it increases the current, which means larger cables. So I think that on the primary you have high voltage and low current (small gauge) and on the secondary you have low voltage and high current (large gauge).
Post #43 onwards
Last edited by routercnc; 13-12-2015 at 07:12 PM.
Hello routercnc, thank you very much for the link ! I have one question though: when looking at your diagram, I see that while wiring both yellow and black together you also wired them to the star point. Is that correct ?
On Wednesday I will go get the fuses I need. I will solder the capacitors and crimp terminals with bigger wires. The nice thing about the set I have is that I am using an old PSU box from a PC and it fits perfectly inside a desktop PC box. Plus it has the integrated switch, and a good start for a star point.
I'll keep you guys updated. Also think it's time to start my build thread.
NO none of the wires from the transformer connect to a star point that is only for all the earths. Also do not connect an earth to the bolt that holds down the transformer unless you do it at the bottom and not at the top like this pic shows as it creates a shorted turn around the transformer. I hope the guy that built this doesn't mind me using it to show the problem.
Last edited by Clive S; 13-12-2015 at 10:47 PM...Clive
I see :) Thanks for the advice :) Jazz had noted that before as well :) Sounds like this guy's control box will blow up some time hu :s
It's funny because I had seen this image before on Google and always thought the setup looked quite nice :)
Oops! Wrong again
Last edited by Robin Hewitt; 14-12-2015 at 10:55 AM.
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