I have 22vac on the rail of the xfmr in one of my amps and need to use 15vac. I know I can use a dropping resistor but would like a more elegant solution. Can anyone furnish me a circuit for that?
Its not easy to drop one AC voltage to another AC voltage. If the load on the supply is constant then a resistor can work as long as the heat is manageable. A capacitor used as a 'watt-less dropper' can also work. Both solutions are only good for constant and known current draws though.
Best solution if you have bought the wrong transformer is simply to bite the bullet and get a more suitable one.
Best solution if you have bought the wrong transformer is simply to bite the bullet and get a more suitable one.
I havent purchased anything yet. The supply is my 115/120 house voltage, as constant as they get I guess. This is actually the optional fan supply voltage and I want it to use a pre-made speaker protection board. I guess as small bridge and a cap would work but need some help stringing them together.
You could always make a small regulator running of the main voltage rails.
You have a 22 vac transformer... so that's giving you 30 vdc approx.
You need a 15 vac transformer which would give 21 vdc approx.
Possible solution. Use a simple regulator fed from the 30 vdc supply to give around 21 vdc. Feed the 21 volts DC into the protection circuit board bypassing any rectifiers etc.
You have a 22 vac transformer... so that's giving you 30 vdc approx.
You need a 15 vac transformer which would give 21 vdc approx.
Possible solution. Use a simple regulator fed from the 30 vdc supply to give around 21 vdc. Feed the 21 volts DC into the protection circuit board bypassing any rectifiers etc.
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