I have a Keen Ocean TTO-13891 toroidal with the following secondary windings:
0-12v (0.25A) RED-RED
0-12V (6.25A) YELLOW-YELLOW
Before I make a silly mistake with the grounding can someone confirm that if I tap a wire off each of the yellows (or reds), join them together I have suitable ground? Or would I be better (read safer) attaching in a couple of diodes in series to create that ground?
Many thanks.
0-12v (0.25A) RED-RED
0-12V (6.25A) YELLOW-YELLOW
Before I make a silly mistake with the grounding can someone confirm that if I tap a wire off each of the yellows (or reds), join them together I have suitable ground? Or would I be better (read safer) attaching in a couple of diodes in series to create that ground?
Many thanks.
I don't understand your question. A transformer does not have a ground, but the circuit it feeds may need a ground. A ground is either the point from which you choose to measure voltages (signal ground), or a means of avoiding touching high voltages (safety ground).
There is lots on the internet, and this forum, about audio grounding.
There is lots on the internet, and this forum, about audio grounding.
Sorry, I shouldn't have written 'grounding' but 'creating a ground' for the power supply circuit (a +/- 10v LM317) which needs AC and a 0v.
There are a number of ways to use this transformer in a DC power supply.
http://www.hammondmfg.com/pdf/5c007.pdf
There are several ways to connect that DC supply to the chassis.
See Section 15.10 here: http://www.valvewizard.co.uk/Grounding.pdf
If you need to build a bipolar DC supply from a single winding with no center tap, then the
option is a voltage doubler, with the connection of the two capacitors taken as the ground.
http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/voldoub.html
The transformer cannot provide "0v". You need to show us the PSU circuit you would like to use. It is the circuit which may provide a ground for the transformer, not the other way round.damiangt3 said:
Is it possible that what you mean by 'ground' is actually a transformer secondary centre-tap? If so, you need to connect one red wire to the correct yellow wire; the joint then acts as a CT. You can then use the transformer as 12V-0-12V at 0.25A.
Thanks for the replies this is what I'm planning to use:
Positive/Negative Adjustable Voltage Regulator Module, for Preamplifier. | eBay
It states dual but when I give it power to the AC1 and 0v I get the +/- voltages I need.
Positive/Negative Adjustable Voltage Regulator Module, for Preamplifier. | eBay
It states dual but when I give it power to the AC1 and 0v I get the +/- voltages I need.
If you use just AC1 and 0 you will get half-wave rectification, so double the ripple voltage going into the regulator.
I better look at getting a transformer with equal dual secondaries 🙁
My long term goal is to have a play with my old Marantz CD5000 and feed each power consumer separately, I need +/- 10v & a 5v. I was hoping to use this transformer to supply the +/- 10v and using the +10v to provide the feed for a 5v superreg needed for the digital part of the circuit.
it doesnt work that way man , at all !!! ;-)
you'll need an other trafo for that job , 3 secondaries , 2 for your symmetric psu and one for your digital psu , best will be 2 trafo , digital and analog stuff "normaly" run with their own power supply , those stuff doesnt realy like to share ground or anything else .
in audio , power supply is a great part of the deal , the better you take care of them the better the result will be 🙂
.
you'll need an other trafo for that job , 3 secondaries , 2 for your symmetric psu and one for your digital psu , best will be 2 trafo , digital and analog stuff "normaly" run with their own power supply , those stuff doesnt realy like to share ground or anything else .
in audio , power supply is a great part of the deal , the better you take care of them the better the result will be 🙂
.
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I know, I know I need to separate the digital and analogue but I want to start small. The CD5000 has one regulator (5v) which I've replaced with a superreg so replacing the crap that supplies it was my first thought.
Buy a 230:0-12, 0-12Vac dual secondary transformer.
It will need to be 10VA for each 130mAdc of output required.
eg. your +-10Vdc needs continuous 50mA and your 5Vdc needs 180mAdc then you total DC continuous current is 230mA. A 20VA would meet this demand.
Add a pair of lm317 regulators to regulate down to +-10Vdc,
Add a third regulator to create your +5Vdc supply.
It will need to be 10VA for each 130mAdc of output required.
eg. your +-10Vdc needs continuous 50mA and your 5Vdc needs 180mAdc then you total DC continuous current is 230mA. A 20VA would meet this demand.
Add a pair of lm317 regulators to regulate down to +-10Vdc,
Add a third regulator to create your +5Vdc supply.
Thank you Andrew. The audiowind regulator I've purchased covers the +/-10v, I've got a Dexa Technologies NewClassD Regulator to provide the 5v.
I did struggle with calculating the transformer sizes so thanks for those details.
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