| bal704 |
I'm getting ready to start on the LM4780 kit from AudioSector.
http://www.audiosector.com/lm4780.shtml
I happen to run across a pair of 24V transformers, but they only have single secondaries. Is there any way to get it these to work for this circuit, or do I need dual secondaries? |
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| Sherman |
| quote: | Originally posted by bal704
I'm getting ready to start on the LM4780 kit from AudioSector.
http://www.audiosector.com/lm4780.shtml
I happen to run across a pair of 24V transformers, but they only have single secondaries. Is there any way to get it these to work for this circuit, or do I need dual secondaries? |
You can use two transformers that have single secondaries. Just use one trafos secondaries for the AC1 H&N and the other secondaries for the AC2 H&N. |
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| CarlosT |
| Bal where did you see the single secondary transformers? Were they toroids? |
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| bal704 |
I bought them locally. They are Mercury Magnetics 24V transformers. I've attached a pic.
Also, if I have to use 2 of them, can I connect both xfmrs to the same AC plug, or will each xfmr need it's own? |
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| I_Forgot |
You can use one line cord to power both transformers. You should also install a fuse. Be careful about getting the line cord "polarity" correct.
The nature of your question leads me to believe you have never wired anything like this before. I recommend that you find someone local to you who has some experience with this sort of thing and have them check your work before you connect power to it.
Test your power supply before you go to the trouble of building and connecting the amplifier circuit.
Good luck!
I_F |
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| bal704 |
Thanks for the help. This is my first PS project, and I intend to build and test it before I hook it up to my amp.
Thanks again |
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| CarlosT |
| What do you do if the tranny has dual 115V primaries? I just wanna run 115V coming in... |
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| CarlosT |
| BTW I just found a super deal on Avel Lindberg encapsulated toroidals...90VA 20V+20V 7% regulation for $20 each. Would this make a decent transformer for a single LM3875? |
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| bal704 |
| Where did you find that deal? Send a link. |
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| Minion |
I can"t really tell from the Picture but those Transformers look a bit too small to Power a Chip amp...There is nothing in the Pic to really tell the size of it but from first impressions it doesn"t look very big....
do you know the power rateings of these transformers?? |
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| I_Forgot |
| quote: | Originally posted by CarlosT
What do you do if the tranny has dual 115V primaries? I just wanna run 115V coming in... |
You connect them in parallel, but make sure you get the phasing correct or you won't get anything out except heat. The correct phasing can usually be identified by the colors of the lead wires or dots marked on the terminals if there are no lead wires.
Dual 115V primaries allow the transformer to be used for 230V input by connecting the windings in series (again, be careful of phasing).
If you have a transformer that has dual 115V primaries and 50V secondary but you need a transformer with a 25V secondary, you can just wire the primaries in series, plug into 115V and you'll get 25V out.
I_F |
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| bal704 |
'do you know the power rateings of these transformers??'
No, I'm afraid I don't. There were no P/N markings on the xfmr, so I don't really know. I'm planning on using it for a small guitar amp, so I don't need anything huge. |
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