Good evening,
I have an issue with connections in the power supply I’m building. Starting from a 0-9V 0-9V toroidal transformer, I connect the windings in series to get 0-18V. Then, in parallel after each of two smoothing capacitors and a series resistor, I connect the two Teddy Pardo regulators.
It works correctly, but when I connect the two GND outputs of the regulators together, the resistors between the capacitors start to smoke. Where am I going wrong?
Thank you for your help
I have an issue with connections in the power supply I’m building. Starting from a 0-9V 0-9V toroidal transformer, I connect the windings in series to get 0-18V. Then, in parallel after each of two smoothing capacitors and a series resistor, I connect the two Teddy Pardo regulators.
It works correctly, but when I connect the two GND outputs of the regulators together, the resistors between the capacitors start to smoke. Where am I going wrong?
Thank you for your help
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Forgive me, but I don’t understand how I should connect everything. Additionally, I connect another regulator on one of the 0-9V windings and do the same on the other 0-9V winding. Could I ask you for a diagram?
You can not create a dual supply with a single transformer winding connected this way.
If you use two single diode rectifiers on one side of the secondary and ground the other
transfomer tap it is already symmetric, but even in this case you can not use the "same"
type regulator for both outputs. You need a positive and a negative version like 7815 and
7915 as example. I did not investigate the "Pardo" units come in both versions or not.
If you use two single diode rectifiers on one side of the secondary and ground the other
transfomer tap it is already symmetric, but even in this case you can not use the "same"
type regulator for both outputs. You need a positive and a negative version like 7815 and
7915 as example. I did not investigate the "Pardo" units come in both versions or not.
I do not want to mess with a moderator, but the circuit in post
6 gives about 2x24V with the 18V secondary and no load. It is
a voltage doubler.
6 gives about 2x24V with the 18V secondary and no load. It is
a voltage doubler.
Somebody inserted a drawing in post 7 which has not been
seen before my post 8 and other posts have been removed.
This is not a political debate.
seen before my post 8 and other posts have been removed.
This is not a political debate.
danieleronchi: for starters you need a dual secondary winding transformer. You will need the right AC voltage the regulatior manufacturer recommends. Probably 2 x 15V but please check. Also check current demand of the load and choose a suitable rated transformer.
In our world vague things and designer names don’t solve technical issues. We work with for instance a device needing +/- 15V at maximum 100 mA. That is about 3W. A 10VA 2x 15V transformer will then work out OK with standard regulators.
In our world vague things and designer names don’t solve technical issues. We work with for instance a device needing +/- 15V at maximum 100 mA. That is about 3W. A 10VA 2x 15V transformer will then work out OK with standard regulators.
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I sincerely apologize; my diagram is actually incorrect. I have two full Graetz bridges, not just one.
Additionally, I was looking for a solution to use only one transformer, but I can add a transformer with dual 0-18V secondaries, as in my previous project.
Additionally, I was looking for a solution to use only one transformer, but I can add a transformer with dual 0-18V secondaries, as in my previous project.