Im building an all in one preamp with pcb mounted trafos and trying to figure out the optimal layout.
The rectifier diodes, should they stay as close to the trafos as possible or to the smoothing caps?
In the 1st scenario i will end up with about 5cm dc traces from the rectifiers to the caps. In the 2nd situation those traces will carry AC.
Which one would be the better solution and why?
The rectifier diodes, should they stay as close to the trafos as possible or to the smoothing caps?
In the 1st scenario i will end up with about 5cm dc traces from the rectifiers to the caps. In the 2nd situation those traces will carry AC.
Which one would be the better solution and why?
The wires from rectifiers to capacitors will carry strong charging pulses. You want to keep those as short as possible and away from the circuit as much as possible. Keep xformer, rectifier and cap close together and away from the circuit.
The DC on the capacitors will have ripple but that is much less aggressive.
Jan
The DC on the capacitors will have ripple but that is much less aggressive.
Jan
Thank you Jan, that certainly should help me sleep better at night. 😀
How about this idea? Ac output trace on the bottom of the board and copper pour ob top. The pour connects directly to chassis ground thus creating a shield layer for the ac traces
How about this idea? Ac output trace on the bottom of the board and copper pour ob top. The pour connects directly to chassis ground thus creating a shield layer for the ac traces
This assumes that chassis ground is clean. It generally isn't as it should be connected to mains safety ground.
You could do a pour connected to signal ground, as long as you only connect it at one point to the signal ground, preferably at the output connection. Make sure no currents flow through the plane.
Jan
You could do a pour connected to signal ground, as long as you only connect it at one point to the signal ground, preferably at the output connection. Make sure no currents flow through the plane.
Jan
Hello Jan,
When using a choke input supply will be better to keep the wires from diodes to the choke as short as possible and twist the wires going from transformer to the diodes OR mount the diodes at the transformer terminals ( EI type) and twist the output wires leaving the diodes?
Greetings, eduard
When using a choke input supply will be better to keep the wires from diodes to the choke as short as possible and twist the wires going from transformer to the diodes OR mount the diodes at the transformer terminals ( EI type) and twist the output wires leaving the diodes?
Greetings, eduard
Wire twisting is always a good idea, but if the various parts are close together it is not always possible. I would say, keep everything as close as possible and if there's more wire, twist it.
Since a diode is a two terminal part, the current that goes into is the same as what comes out so in that sense, there is the same 'current junk' on both sides.
Jan
Since a diode is a two terminal part, the current that goes into is the same as what comes out so in that sense, there is the same 'current junk' on both sides.
Jan