Hi!
Atached is a psu schematic, based on LM317/337 regulators. I expect to draw around +/- 400ma from the +/- 17v rails (LM317/337). Nothing fancy, quite normal circuit.
But my question is about the part of the circuit i signaled within a square: These are two additional positive rails derived from an RC filter after the positive side of the diode bridge. So, from the diode bridge there is an RC filter 10R/1000uf, and then two LM78xx linear regulators.
I have to say that i don't expect to draw much current from these two additional rails, as they are to supply current to six 24v relays (2880R coils), and two lamps within round vumeters, that i will supply with 8v.
My question is just if the arrangement in the circuit signaled within the square is ok.
Thank you for your advise!!
Jay x
Atached is a psu schematic, based on LM317/337 regulators. I expect to draw around +/- 400ma from the +/- 17v rails (LM317/337). Nothing fancy, quite normal circuit.
But my question is about the part of the circuit i signaled within a square: These are two additional positive rails derived from an RC filter after the positive side of the diode bridge. So, from the diode bridge there is an RC filter 10R/1000uf, and then two LM78xx linear regulators.
I have to say that i don't expect to draw much current from these two additional rails, as they are to supply current to six 24v relays (2880R coils), and two lamps within round vumeters, that i will supply with 8v.
My question is just if the arrangement in the circuit signaled within the square is ok.
Thank you for your advise!!
Jay x
Your AC waveform may distort if you look at the current (lop-sided). I modelled a full bridge and a voltage doubler off the AC 1/2 cycles ended up drawing more current off 1/2 than the other.
Hi!
Thank you for your response!
So, because the positive voltage rails draw more current, there will be a bit more noise at the positive output rails... makes sense!. But, what about the rails arrangement?
Jay x
Thank you for your response!
So, because the positive voltage rails draw more current, there will be a bit more noise at the positive output rails... makes sense!. But, what about the rails arrangement?
Jay x
Hi jay,
you don't have enough voltage for the 24v regulator. A 18v transformer will give you 25v peak, minus rectifier, minus ripple, minus 10 ohm resistance minus voltage needed for regulator...
you don't have enough voltage for the 24v regulator. A 18v transformer will give you 25v peak, minus rectifier, minus ripple, minus 10 ohm resistance minus voltage needed for regulator...