I did a search but didn't find the answer to these questions...
Is it OK to stack identical 10VA toroids to save space?
And can the radiated magnetic flux be reduced by wiring them out of phase...and is it safe to do so? Or will it negatively affect their performance?
Mike
Is it OK to stack identical 10VA toroids to save space?
And can the radiated magnetic flux be reduced by wiring them out of phase...and is it safe to do so? Or will it negatively affect their performance?
Mike
That's fine. The magnetic field is almost entirely within the core of the transformer. There's some leakage field, but as long as we're talking about power transformers I wouldn't worry about that.
If we're talking signal transformers or output transformers in vacuum tube circuits I'd be more concerned about coupling between transformers.
Tom
If we're talking signal transformers or output transformers in vacuum tube circuits I'd be more concerned about coupling between transformers.
Tom
"To save space" indicates to me that we're talking mechanically.
Tom
Stacking, but don’t make a loop to support the other end of the bolt.
I have 3 currently in my circlotron (need another two to finish it). I don’t stack but they’re about an inch from each other.
I have 3 currently in my circlotron (need another two to finish it). I don’t stack but they’re about an inch from each other.
Hi Mike,
The effects of any coupling that results from stacking can be reduced by increasing the distance between the cores. If you stack mount them directly to each other the cores are very close. Adding a 1/2" spacer would likely double or triple this distance, a 1" spacer could be 4 to 6 times more distance, etc. If forced to stack perhaps adding spacer(s) can be done. Also, have you tried calling a manufacturer? They might have past experience with of this type of installation. Good Luck.
Bill
The effects of any coupling that results from stacking can be reduced by increasing the distance between the cores. If you stack mount them directly to each other the cores are very close. Adding a 1/2" spacer would likely double or triple this distance, a 1" spacer could be 4 to 6 times more distance, etc. If forced to stack perhaps adding spacer(s) can be done. Also, have you tried calling a manufacturer? They might have past experience with of this type of installation. Good Luck.
Bill
Just to clarify, I'm using two AnTek AN-0110 - 10VA/10V transformers to build a low noise (hopefully) power supply for the active pickups on my bass guitar. So I thought maybe stacking them will save some space, and reduce the overall radiated field if they were wired anti-phase. The second one should arrive in a couple of days, so I think I'll just run some tests to see what shakes out.
Thanks to all.
Ps...I'll post the results, if anything significant shows up.
Mike
Thanks to all.
Ps...I'll post the results, if anything significant shows up.
Mike
I wouldn’t underestimate the size of the mag field from a toroid transformer. Without a load, the field is small and mostly confined to the core. However, the field is enough to cause problems if picked up by wiring loops on the input to amp and preamp stages. Things quickly degenerate once you connect a PSU and you have large charging pulses into the reservoir capacitors. These cause a dramatic increase in the radiated field that can really only be cured with a GOSS band or steel transformer enclosure (I’m talking here about getting noise peaks to < -110 dBV).
As an experiment, wind 10-15 turns of wire into a large coil measuring c. 3” in diameter and wire up to a pair of 32 Ohm headphones. As you pass this could over the toroid, the 100/120 Hz hum can easily be heard. In your specific case, wire the transformers out of phase and also rotate the top transformer wrt the bottom one to find the noise null point. then fix the transformers wrt each other. Once that’s done, then rotate the transformer pair to find an even lower noise null point.
As an experiment, wind 10-15 turns of wire into a large coil measuring c. 3” in diameter and wire up to a pair of 32 Ohm headphones. As you pass this could over the toroid, the 100/120 Hz hum can easily be heard. In your specific case, wire the transformers out of phase and also rotate the top transformer wrt the bottom one to find the noise null point. then fix the transformers wrt each other. Once that’s done, then rotate the transformer pair to find an even lower noise null point.
The active electronics and pickups are mounted in the body of the guitar. This supply will be on the floor and also power a couple of effects pedals, so it won't be anywhere near them...I'm probably overthinking the whole thing like I usually do.
Mike
I'm back!
I thought I'd let y'all know what I found out...
Using two 10 VA / 10 VAC X 2, AnTek AN-0110 toroids.
Stacking them or sitting right next to each other, in phase or out of phase...none of it mattered. I couldn't detect any real difference for any mounting orientation of the two transformers, unloaded or heavily loaded.
So...I was overthinking the whole thing like I usually do. 😵
Mike
I thought I'd let y'all know what I found out...
Using two 10 VA / 10 VAC X 2, AnTek AN-0110 toroids.
Stacking them or sitting right next to each other, in phase or out of phase...none of it mattered. I couldn't detect any real difference for any mounting orientation of the two transformers, unloaded or heavily loaded.
So...I was overthinking the whole thing like I usually do. 😵
Mike
