Thread: Toroid transformer no ouput
Hello :) I thought I'd stop bothering Jazz privately and ask for the communities help as well, so that other may benefit from this :)
I built my linear power supply today. When powering it, the only thing I heard was th transformer loading for two seconds, then a tiny "click", and I measured the output current of the PSU: nothing.. No fumes, no explosion, no bad smell, no heat, nothing was heard other than than a very little teeny tiny two second load, then click.
So I unpluged wires, and checked each step separately. Turns out the transformer does not output current, even though it has proper 230V input current (checked). I tried with outputs wired in series or in parallel. Nothing comes out.
Does anyone have an idea ?
Thank you in advance !
Hello Clive :D
So sorry, my post lacked a few details about the setup. Give me a few minutes and I'll get some pictures. In the meantime, here is the list of parts I ordered (Jazz checked them before purchase):
The transformer came with no ground wire, only load and neutral. Here is how I wired things:
To answer your question #2:
DC to transformer:
230V brown (load) on transformer's brown
230V blue (neutral) on transformer's blue
Transformer wired in series: (AC pins are vertical and diagonally opposed, DC pins are vertical + horizontal where horizontal is DC+ ans diagonally opposite pin is DC-)
- black and yellow together on one of the AC pins of the rectifier
- red and orange together on the other AC pin of the rectifier
Rectifier to capacitors:
DC+ to first capacitor's +
DC- to first capacitor's -
capacitors wired in parallel: + to + to +, - to - to -.
Capacitors to screw terminals:
+ to on terminal
- to another one
nothing is connected to the terminal
To answer #1:
The first time I measured from the screw terminals. Then, after unplugging everything to find out the transformer is not outputting current, I put my voltmeter on the black+yellow pin (they're crimped together on a ferrule) and on the red+orange (also crimped on a ferrule).
Not sure how to perform the second part of your question :/ ?
Photos will follow in a few minutes ;)
Here you go :)
Last edited by eurikain; 12-12-2015 at 11:07 PM.
First check if the primary side is ok. Some transformers have tiny heatfuses in it.
Normally no problem, because you can buy the fuses for small money, but before you can change it, you must disassemle the complete transformer. I don't know if its possible without destroying them.
Last edited by eurikain; 12-12-2015 at 11:31 PM.
I think you have the transformer wired wrongly. Firstly to make sure no damage has happened, disconnect the secondary side of the transformer at the screw terminals and measure the AC voltage between Red and Black - should be 25V AC, also check between Orange and Yellow - should also be 25V AC. If this is ok then the transformer is working.
Assuming that you are making a 70V DC power supply. Connect the Red lead to one of the AC terminals of the rectifier and the Orange lead to the other AC terminal. Then connect the Black and Yellow together. These should not go anywhere else. In this configuration the secondary windings are now in series.
Apply mains power and measure the DC voltage. You should see 70V - 75V DC with no load. Be careful as the capacitors will take quite a long time to discharge.
eurikain I think Graeme is correct. But lets start with basics First disconnect the transformer and measure the resistance of the primary (blue and Brown) wires it should be quite low if you don't have a meter just use a battery and lamp to see if you get continuity. If that sis OK do the same for the secondary coils. It probably is OK.
The next step is to connect the primary (brown and blue) to the 230V supply and then as Graeme states measure the voltage on the two secondary coils if you are getting 25V on each you are good to go.
Try that and report back...Clive
The Following User Says Thank You to Clive S For This Useful Post:
Yes, now I understand what I did wrong. I didn't think that black and yellow were meant to be together and go nowhere else and that only orange and red were meant to be used separately on the rectifier.
I'll go do the checks you asked right now and report back in a few minutes... oh boy I hope I didn't break the transformer... or a new one shall be ordered tonight... ! Learning the hard way.. oh boy x)
Last edited by eurikain; 13-12-2015 at 10:44 AM.
[s]Transformer primary is OK, my ohmmeter shows a low resistance as you said Clive.[/s]
No output on either of the secondary coils. When measuring the resistance it works fine, but no voltage comes out....... :'((((((
What's up doc' ?
Last edited by eurikain; 13-12-2015 at 10:57 AM.
You can also measure the secondary resistance, should be have a low resistance on each and a high resistance between them. Have you checked that you are getting mains voltage to the primary. I would have expected that your input fuse would have blown with your original wiring.
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