Winding a toroidal transformer without the right equipment is very difficult from what some of the experienced members in here have said. I wouldn't do it myself. Iv'e made a couple of bobbin inductors but thats a different story. 😉
yeah, i'd imagine a torroid would be harder to wind .. but a normal EI core shouldn't be THAT tough .. i could be wrong though ..
in any case .. i thank you philo for all the help .. amazing help i get from you 😉
in any case .. i thank you philo for all the help .. amazing help i get from you 😉
Phil,
To tell the truth, I am in somewhat of a unique situation, and one that only occurred to me a few days ago. My flat is only a half mile away from two of the most powerful radio/tv transmitters in the UK, at Crystal Palace.
I too had problems that were solved, ( more through luck than judgement), with earth buzz with the LMs, that don't seem to be a problem with the OPAs, but I have a real problem with RF, so much so that I have now given up on the reduced gainclone, and am trying to limit RF effects as much as possible, and this seems to be a problem especially with the fast CF chips I am playing with with the CFMSS chip amp I am building at present. So I am not sure my findings are relevent to other's situations.
Ho hum🙄
To tell the truth, I am in somewhat of a unique situation, and one that only occurred to me a few days ago. My flat is only a half mile away from two of the most powerful radio/tv transmitters in the UK, at Crystal Palace.
I too had problems that were solved, ( more through luck than judgement), with earth buzz with the LMs, that don't seem to be a problem with the OPAs, but I have a real problem with RF, so much so that I have now given up on the reduced gainclone, and am trying to limit RF effects as much as possible, and this seems to be a problem especially with the fast CF chips I am playing with with the CFMSS chip amp I am building at present. So I am not sure my findings are relevent to other's situations.
Ho hum🙄
The toroids I'm using are potted inside, so it's not easy to do some extra windings. I had to break the potted stuff, but I was doing it in order to convert it to 18-0-18 V AC. Otherwise you might have to drill small hole for you LED windings 😉 It will work as well. As long as wire is enameled you can wrap it one over the other. The size is about 2.75 by lslightly less than 5" in diameter.
aw man, i didn't even realize that .. how hard would it be drill maybe a 2-3mm hole in the potting compound? and what sort of problems could that create? (like is the potting compound solid or powder?)
ps. i just went to radioshack and bought the hookup wire i need as well as the magnet wire .. i think i'll start constructing the ps cables tonight 🙂
as well i gotta finish my speaker cables too!!! 🙂
oh and (too many questions) how close to the actual windings would i have to drill the hole? could i just drill it in the middle of the potting compound???
oh AND .. what sort of voltage should i expect for 6 windings?
ps. i just went to radioshack and bought the hookup wire i need as well as the magnet wire .. i think i'll start constructing the ps cables tonight 🙂
as well i gotta finish my speaker cables too!!! 🙂
oh and (too many questions) how close to the actual windings would i have to drill the hole? could i just drill it in the middle of the potting compound???
oh AND .. what sort of voltage should i expect for 6 windings?
There is actually a hole in the middle of the potting compond for the mounting screw. I would rather drill another one, but it has to be done carefully so you won't damage the existing windings😉
The compaound is hard, but easy to drill, it's like 2 parts epoxy.
The compaound is hard, but easy to drill, it's like 2 parts epoxy.
I've actually seen people wrap wire all the way around the outside of the toroid to get the desired voltage to the LED. What is the problem with doing this? No holes to drill.
arund the outside of the torroid???
you mean like wrapping it length wise (as opposed to threading it through the hole in the "donut")?
you mean like wrapping it length wise (as opposed to threading it through the hole in the "donut")?
usekgb said:
You might see people wrapping the wire, but did you see the LED giving light? I never tried that, so I don't know. But I tried to wrap toroid like that with a copper band (for shielding) and it never got hot (the copper band)😉
usekgb said:
Well, I was little bored and had a toroidal out and hooked up so I tried both ways;
circumferential (all around the outside, perpendicular to the other windings) and diametric(from outside across the center) configurations and neither worked. I tried the normal way and was succesful.
Usekgb, can you describe the configuration you saw with a little more detail? I think the first method would not be correctly orientated to the field and the second self-canceling.
yeah, that's what i thought when i read about how the winds were done .. didn't really think it'd work
but as peter suggested, maybe they were shielding?
but as peter suggested, maybe they were shielding?
The one's I've seen so far are diametric. The windings go over the top, down the side, across the bottom and back up. It usually takes about six turns or so from what I've seen. I haven't actually tried this, but I've seen working models of people's who have. Try winding a few turns of wire around your toroid that way and measure the AC voltage coming off the two leads. You should be getting something. If you need more voltage, just add a few more windings untill you get the coltage you need. If it doesn't work, let me know so I won't do it.
I tried a few variations and up to ten windings and I haven't got it to work. Anyone else get it to work?
well i sadly don't have my toroid here quite yet .. not for another month!!!
so sad 🙁
but it doesn't make sense that it would work
so sad 🙁
but it doesn't make sense that it would work
Shorted turns
FYI, from Plitron's technical notes:
Shorted Turn Condition
A completed path by any conductor passing through the center of toroidal transformer, around the outside is a shorted turn (eg: the top of the mounting bolt shorted to the chassis). As with any short circuit, this condition will give rise to high circulating currents, and high heat. The transformer may be damaged beyond repair.
se
FYI, from Plitron's technical notes:
Shorted Turn Condition
A completed path by any conductor passing through the center of toroidal transformer, around the outside is a shorted turn (eg: the top of the mounting bolt shorted to the chassis). As with any short circuit, this condition will give rise to high circulating currents, and high heat. The transformer may be damaged beyond repair.
se
yes .. but this isn't a completed circuit .. or am i wrong?
since you do the windings, then run one end through a diode, then to an LED, then to the other end
just like the normal secondaries .. so long as you don't touch the two wires, you're ok ..
running them through a circuit is no problem
since you do the windings, then run one end through a diode, then to an LED, then to the other end
just like the normal secondaries .. so long as you don't touch the two wires, you're ok ..
running them through a circuit is no problem
elizard said:
Well unless it's a completed circuit, your LEDs aren't going to work. To get an LED to light up requires a complete circuit.
Depends on the impedance of the circuit. If the impedance of the circuit is too low, there most certainly can be problems.
se
yeah .. sorry, didn't type it properly ..
it is a completed circuit, but the impedence of the circuit is more than enough to prevent a short like they're describing ..
they're describing taking a piece of wire and just looping it through connecting both ends .. not good at all!
it is a completed circuit, but the impedence of the circuit is more than enough to prevent a short like they're describing ..
they're describing taking a piece of wire and just looping it through connecting both ends .. not good at all!
elizard said:
But you said previously just using a wire, a diode and an LED.
Anyway, I only brought up the issue of shorted turns so people might think twice before willy-nilly looping wires through toroids. 🙂
se
Steve,
I am not sure what your saying. Would adding a small secondary of six turns creating @4V and few hundred mA cause a problem in a large toroid? I not sure what the effect on the rest of the transformer would be. Would this translate to heat in the other windings?
I am not sure what your saying. Would adding a small secondary of six turns creating @4V and few hundred mA cause a problem in a large toroid? I not sure what the effect on the rest of the transformer would be. Would this translate to heat in the other windings?
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