Can one dual secondary trafo be used with 2 brianGT snubberized boards?
Or would it need to have 4 secondaries ?
This question implies an assumption that 2 snubber boards are better than 1. If that is right? then a follow up question is whether 2x say 20000uF snubberized boards is better than 1x 40000uF board?
Or would it need to have 4 secondaries ?
This question implies an assumption that 2 snubber boards are better than 1. If that is right? then a follow up question is whether 2x say 20000uF snubberized boards is better than 1x 40000uF board?
Hi,
connect the two secondary wires to each pair of ~ bridge connectors.
This will give you two DC outputs. You can then run two independant DC PSUs to your loads. Not quite as good isolation as 4 secondaries, but much better than a shared PSU for a stereo amp. You are starting to go down the dual mono route but using the cheap method.
Connect the transformer central common to the power ground and run both the PSU capacitor commons back to the same power ground. Try to keep the layout to ensure all the power ground wires are fairly short. Then run a wire from power ground to your Central Star Ground (CSG). Do not combine the power ground with the CSG!!!!
connect the two secondary wires to each pair of ~ bridge connectors.
This will give you two DC outputs. You can then run two independant DC PSUs to your loads. Not quite as good isolation as 4 secondaries, but much better than a shared PSU for a stereo amp. You are starting to go down the dual mono route but using the cheap method.
Connect the transformer central common to the power ground and run both the PSU capacitor commons back to the same power ground. Try to keep the layout to ensure all the power ground wires are fairly short. Then run a wire from power ground to your Central Star Ground (CSG). Do not combine the power ground with the CSG!!!!
This is the chipamp snubber board. http://www.chipamp.com/images/ps.gif
So let's say I've got 2 of these running off one pair of 25V secondaries.
Is it ok to connect an amp to just one board and leave the other connected but not being used?
How much power would the unused snubber board draw?
Thanks.
So let's say I've got 2 of these running off one pair of 25V secondaries.
Is it ok to connect an amp to just one board and leave the other connected but not being used?
How much power would the unused snubber board draw?
Thanks.
Hi,
delete the AC2 and make connections from AC1 to the empty ~ bridge inputs.
The unused PSU will draw a big power pulse on start up then draw very little current afterwards. 2k2 + electro leakage = very low power.
Has anyone on the thread queried the value of the 2k2 resistor. It seems excessively low.
You may benefit from adding snubbers to each of the diodes.
delete the AC2 and make connections from AC1 to the empty ~ bridge inputs.
The unused PSU will draw a big power pulse on start up then draw very little current afterwards. 2k2 + electro leakage = very low power.
Has anyone on the thread queried the value of the 2k2 resistor. It seems excessively low.
You may benefit from adding snubbers to each of the diodes.
OK thanks. So I'm using 1 secondary to feed both rectifiers on the 'snubber' board (and the other secondary to drive my other board).
There was good Intro to rectification on someones diy audio site but I can't lay my hands on it now, I think that would have covered these questions.
There was good Intro to rectification on someones diy audio site but I can't lay my hands on it now, I think that would have covered these questions.
Hi,
my situation: One Trafo with one secondary. What's better for powering two channels:
two bridge-rect. with CLC (Cap-Inductor-Cap) filter each or
one bridge-rect. with CLCLC filter with the two channels sharing the supply.
Greets, Dave
my situation: One Trafo with one secondary. What's better for powering two channels:
two bridge-rect. with CLC (Cap-Inductor-Cap) filter each or
one bridge-rect. with CLCLC filter with the two channels sharing the supply.
Greets, Dave
Hi Jimbo,
OOPS I slipped up. I forgot you need bipolar supplies.
Connect the two secondaries in series. Take the top connection to ~ bridge and take the bottom to the other ~ bridge. Now take the same two secondary connections to the other bridge.
Connect both the capacitor commons back to the transformer centre tap. Connect the centre tap to your central star ground.
Now you have two PSUs that can feed two channels of power amp.
OOPS I slipped up. I forgot you need bipolar supplies.
Connect the two secondaries in series. Take the top connection to ~ bridge and take the bottom to the other ~ bridge. Now take the same two secondary connections to the other bridge.
Connect both the capacitor commons back to the transformer centre tap. Connect the centre tap to your central star ground.
Now you have two PSUs that can feed two channels of power amp.
Does it matter which ends of the secondaries I connect? In which case I would need to examine the trafo or get info from the manufacturer.
Hi,
YES, it matters.
Connect the secondaries in series and measure the voltage on the two spare ends.
If you have two times the secondary voltage then the windings are in phase and you can then connect into your PSU circuit.
If you measure almost zero volts then the secondaries are out of phase and you must swap around one pair of secondary connections.
After you have the correct voltage on the series connected secondaries, it then does not matter which ends are connected to the bridge~ since both bridge inputs can accept either AC connection.
YES, it matters.
Connect the secondaries in series and measure the voltage on the two spare ends.
If you have two times the secondary voltage then the windings are in phase and you can then connect into your PSU circuit.
If you measure almost zero volts then the secondaries are out of phase and you must swap around one pair of secondary connections.
After you have the correct voltage on the series connected secondaries, it then does not matter which ends are connected to the bridge~ since both bridge inputs can accept either AC connection.
So, I'm finally about to build.
If I follow the advice above, ie series connect my secondaries and connect to bridge, aren't I going to get twice the voltage I wanted out from the bridge? I've got 25V secondaries.
If we go back to the start > Is there anything wrong with connecting the two power supply boards in parallel, ie my four secondary wires are paralleled to the same point on each PS board http://www.chipamp.com/images/ps.gif
If I follow the advice above, ie series connect my secondaries and connect to bridge, aren't I going to get twice the voltage I wanted out from the bridge? I've got 25V secondaries.
If we go back to the start > Is there anything wrong with connecting the two power supply boards in parallel, ie my four secondary wires are paralleled to the same point on each PS board http://www.chipamp.com/images/ps.gif
Hi,
the bridge will need a minimum PIV =150V (3 times the rms voltage)
your 25Vac - 0 - 25Vac will give 71Vdc on full load and about 75Vdc on open circuit.
But you have the centre tap from the junction of the two secondaries.
Connect this centre tap to the common between the series connected smoothing capacitors. Each capacitor will have half the output voltage across it.
So 25 0 25 gives +-35.5Vdc. This is good for about 50W into 8ohm.
the bridge will need a minimum PIV =150V (3 times the rms voltage)
your 25Vac - 0 - 25Vac will give 71Vdc on full load and about 75Vdc on open circuit.
But you have the centre tap from the junction of the two secondaries.
Connect this centre tap to the common between the series connected smoothing capacitors. Each capacitor will have half the output voltage across it.
So 25 0 25 gives +-35.5Vdc. This is good for about 50W into 8ohm.
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