CEvonK
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This is my project. I'm in need of some guidance. I cannot find a manual or circuit diagram for this model. There is a basic quick start manual for the current, very different, model, but it has little helpful information.
I want to convert this "automatic" charger to a continuous output manual device by defeating (deleting) the control circuitry. I want continuous 24V DC output to use for an electrolysis project. I know only the most basic electrical theory regarding AC and DC circuits: I have wired both a DC solar array and an 120 VAC distribution system in a school bus, and I can service small electric motors with brushes and bearings. I can make basic use of a volt/ohm meter.
There are no large capacitors in this charger. I understand where the mains are, and what is in them. I have watched several YouTube videos about modifying similar chargers, but none of those chargers had a PCB like this one. I can detect 24V current on the output side, but at very tiny levels because of the charging circuitry.
Mains leads. Positive (red), Negative (blue), Ground (green). Again, nothing needs to be done on this side of the transformer (except not get shocked when it is powered up.)
(I will clean this up before I start doing anything inside the box.)
Input side of transformer where mains are attached. I do not know what the small component is. I suspect it is something that prevents current backflow, like a diode. My ignorance is boundless. I don't think I need to do anything with these connections, as they are simply the 120VAC input to the transformer.
Output side leads from the transformer at top of transformer. These appear to power the board. I have not tested the voltage with voltmeter.
My present thought is that cutting (and terminating) these wires will defeat the board. That would be fine, as long as I can draw current from the DC output wires. I suspect (note that word) that these are taps drawn from the coil, and that if they were severed and individually "capped off", they would not affect the operation of the transformer. That is only a suspicion...
Below these, and apparently larger, are the output leads that feed the working output of the board. There are two leads on each polarity that I believe to be 24V AC output. I think that one passes through a rectifier, is held out of phase with the other, and then is combined on their respective sides as a stable 24V DC current (that's the extent of my electronics theory, just about.)
24V AC is of no use to me, so I'm pretty sure that I must have the rectifiers to produce the DC output. (Pretty sure = confidence level 99%, but that may or may not match electrical reality.
Output side of board. Two leads in blue (Negative), and two in red (Positive). Both have rectifiers 52015L, and are also marked with a capital I and the letter 1 or 2 (I1 and I2). The positive side rectifier is just out of the frame on the right. It is installed the same as the negative side.
Both leads on each side appear necessary for supplying rectified DC voltage.
I want to bypass the PCB and draw continuous output current from these leads. To do this I need to defeat (remove) pretty much the entire circuit board, as it controls the output power, and will not supply current when there is not at least a flat battery with sufficient residual charge attached to the charger that the charging circuitry can detect.
I want this to be like an old style of manual battery charger. So, here is the question:
Can I disable the upper leads that feed the circuit, cut off all but the rectifier portion of the PCB, and just draw straight DC current? That is, will the transformer still output current through the 24V side to the output, if I disconnect everything else?
ufoara
full pics of both sides of the board would be a good start. Another option might be a 200w+ laptop charger. Something from a engineer class or gaming class laptop. Probably only 19v but quick YT lookup for "using laptop charger for electrolysis" yields a DIY
CEvonK
I have considered it, but this was at hand in the thrift store for $3.75. If I can bodge it, it will be adequate for my needs. If I can bodge it.
lightfoot2
no
CEvonK
Not even for $3.75 at the thrift store, and the chance to learn how not to do something? :-)
lightfoot2
Oi. Start by studying full wave bridge rectifiers and build your own.
lightfoot2
And watch out if you see a second set of wires from the transformer going to a large can shaped thing. That is a capacitor for power factor correction and the voltage on that is very high. Maybe lethal high. Higher than the 120 volt input . Beware.
1reallyhappydude
A few hints, it is a center tapped transformer, likely 48 v telco 24 - 24 half wave circut. The metal square doodad is a thermal cutout might be the autoreset type, it's supposed to be a short normally. I'm happy to see this as I have the same charger. I have the parts bridge rectifier 1200 uf 63v capacitor and a pair of those fancy buck converter modules from Amazon . Need another bridge rectifier and cap so I can make a bipolar power supply.
CEvonK
When looking for the manual/schematic, I found many of these for sale, used, online. Prices were all over the place, but this one was $3.75 at the thrift store, so, what the heck, why not...
If I make any progress, I'll post it. If I don't post anything, you know I have nothing to show for my efforts.
1reallyhappydude
New in the cardboard box transformer is 158 cdn so good start. I'll post pictures of the bits tomorrow.
Gindipple
There's a reason they make schematics, without one you're flying blind
CEvonK
" I cannot find a manual or circuit diagram for this model. "
Zombieds
That doesnt mean plow ahead anyway.
Gindipple
Then you're going to have to do some research. look at various charging circuits. Learn what components do what. having an oscilloscope handy will help a lot too. But just blindly excluding a board doesn't seem like the way to go.
toolzgalore2
I thought electrolysis worked better at lower voltages like 2 or 3 volts?
CEvonK
I'm not sure voltage is as important as current. This is a low tech project. The current will be limited by the concentration of the electrolyte solution, and judged by observation of electrolytic activity - start with a weak solution, and add to it as needed. That does work, as I have seen it demonstrated. I may be wrong about the current.
toolzgalore2
It was my understanding that anything over 5 volts is wasted since it doesn't require more than a volt and a half or something like that, assuming gold electrodes, to break down water, then like you said you need gobs of current, but the transformer probably has a duty cucle that may not allow it to run as high as you need it to before it starts to heat up and let the magic smoke out
CEvonK
I am looking into this further. My understanding was that current needs to be limited to avoid damaging the underlying material, as too active a solution is erosive.
I think what we are really speaking of is Amperage, perhaps, 24V at .1 Amps is a lot of voltage (relatively) but not a lot of current, being equivalent to 12V at .2 Amps or 6V at .4 Amperes.
My understanding of the process is very likely flawed.
Zombieds
Are you prepared to bypass fuses?
CEvonK
I only see one identifiable fuse, which is on the Positive output lead, and I would maintain that feature. I could be wrong. I want to delete the entire PCB except the portion with the rectifiers and immediately around the output leads. This may not be possible.