I have a constant current transformer - along with capacitors and chokes and a PCB with electronics, from a Motorola or Schumacher battery charger (Motorala Type: 25E83071P03 or Schumacher 93-013-419). I think made in 1990. Outputted 14.25V or 13.8V depending on which outer taps on secondary was chosen.
I've no idea what the electronics did on the PCB, but centre-tap (CT) of secondary is positive and the outer taps go to chassis via rectifiers. CT goes to a capacitor of 97,000 uF, and then a choke, then another capacitor of 73,000 uF.
Wires (probably "signal" voltages) from both of the outer taps of secondary goes to the PCB.
The tank circuit has the capacitor. But both ends of the capacitor go to the PCB - one of the wires via an iron-cored choke (not some small RF choke).
Okay, the question is, can a basic PSU be made with the following items only?:
Constant-voltage transformers are NOT TRANSFORMERS. They do not have a single magnetic circuit with primary and secondary windings, Leave it in its original configuration, it's not nearly as useful in any other circuit.
Yeah, but the only regulation you'll get is what the CVT regulates to. (or whatever you slap onto the output) What you've just described is the bog-standard introductory basic DC power supply. :-)
Now, if this CVT is actually something like a mag amp, then, of course, all bets are off. ;-)
What, you're guessing? The classic ferroresonant power supply has a third-harmonic resonant circuit, saturating magnetic links, and that saturation switches the flux between two (or more) magnetic paths. You can't have the third-harmonic winding coupled to the input AC , it'd damp the resonance quickest. There HAS to be a second magnetic circuit.
Not conventional at all. The resonant capacitor is still connected just as in any ferroresonant design. The original poster was considering disconnecting that resonant capacitor and using it for something else. This example just shows the use of the harmonic-only winding (it takes output in a different way from the assembly, it does NOT detach the resonator).
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OK, maybe you're right, but so what?
The point is that they _are_ transformers, which you said they
weren't, so since they're used to transfer power to a load, from a
source, magnetically, via mutual induction, what are they if they
aren't transformers?
By 'remove the magnetic breaks' you mean you are changing the magnetic core configuration? This chunk of iron was NEVER intended to make a simple transformer, it was an integrated magnetic component of a transformers/saturating link/resonant assembly, and was well designed for that purpose. That purpose only.
It also delivered regulated AC output. It's PERFECT for driving, for instance, 12V halogen lamps (they last longer on AC).
Not to worry too much; it will work as a conventional transformer, the iron is the same, it's just terribly stupid and wasteful to tear apart an already working ferro-resonant transformer. The guy probably won't burn the house down, but he's shot himself in the foot by degrading a working ferro CVT to a linear.
I used to work for a guy who designed ferroresonant transformers. The "official" name for those "magnetic breaks" is "shunt(s)"
Take them, and the resonant winding away, and it's no different from any other silicon steel transformer core, except for the HUGE winding windows.
One time, he designed a new ferro xfmr, and I was at the bench testing it - there was a mongo variac with a knob about the size of a steering wheel, and big AC voltmeters and ammeters.
So, I plopped this brand new ferro transformer on the bench, start cranking up the variac, and at about 3 VAC on the primary, it was drawing about seven amps! I freaked, looked at the boss (the guy with the black magick knowledge of how to design one of those beasts), and he was beaming: "It's regulating!"
The primary makes more flux than is needed; the shunts let that flux slosh around the core, which might or might not saturate on the peaks - the resonant winding makes saturation pretty much irrelevant, because the magickal confabulation of the magnetic shunts and the resonant circuit (they use big can capacitors for what he called "the ferro winding") result in a pretty much constant-voltage output.
I agree, it's kind of stupid to dismantle a working ferroresonant constant-voltage transformer; but the worst that will happen is:
If you don't use enough turns in the primary, it will burn out, same as any other iron core coil across the mains;
All you'll have is a plain ol' ordinary linear transformer, with all their attributes, so to speak.
The reason not to tear it apart isn't danger, it's why screw up something that's already working as advertised? And he could very easily have changed the number of turns on the secondary to get any output he wanted.
I thought if it was not drawing it's load current, it was going to be wasting power. I know they run hot. So, I thought, make it a regular liner transformer.
It could be put back again, in theory, but I'll just dabble and hopefully make a nice regular linear transformer. Rich
one thing about those transfomers though... I've had a few power supplies that use them and they work very well when they work, but it seems every one...eventually the capacitor fails.... they are oil filled 600V or more and they must be under heavy stress. I even repaired one with a replacment cap and after a year or so, it failed too.... The cap fails short and without the resonante winding, it just stops working, no large current or anything, but no output...
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