Building a 24v dc power source

We went the cheap Chinese power supply route. These are inexpensive, turn-key, run right out of the box. I have, however, found that all of our spares are dead. Unfortunately, I found this out when we needed to install one at short notice. I later on saw on the Internet that you have to test and burn these in, and discard the rejects before you need one. I had four spares, and I still came up short when they just asked for one. And, they failed in different ways, just sitting there.
 
One thing I learned working on computers is that you do not want to go cheap on the power supply. They fail in various ways and I've seen them take out everything attached to them when they do. It's more likely they just stop working, but when you have expensive equipment connected to them, you're always better off getting at least a mid-grade unit.

This is less of an issue with the old school transformer based supplies. The isolation helps. But they can have filter components fail, usually cheap capacitors, that then feeds all kinds of noise into the circuit. How much that matters depends on what you have connected.

Both cases are annoying, as the manufacturer might have saved a couple bucks at most. I understand that's then over millions of units, but it is still annoying. Particularly as the savings don't filter to the customer.
 
An after-thought to maybe clear up some confusion.

A filtered circuit is simple. A capacitor of 1000 microFarads(uF) per amp will filter 60 cycles to about 5%. Sufficient on non-critical loads. But doesn't control the actual voltage. That's a function of the homebrew transformer I described earlier. For a motor load, filtering really isn't necessary. Maybe a few mics to keep down electrical noise, but even then no big deal. If the winding comes out to 23 volts or 26 volts, the filtering has no effect.

A regulated circuit is much more complicated and you would be advised to purchase one. I have been an EE for many years, longer than some of your responders have been alive. If I need a regulated supply, I won't build anything larger than an amp or so. Just buy one and be done with it.

But not for a motor load. Just build a transformer supply and use a speed control, usually a duty cycle controller. The supplier I often use (Marlin P Jones Surplus) has them for 10 or 15 bux or so. Several other sources have similar availability. They are not uncommon, albeit usually Chinese.

A regulated supply, on the other hand, will supply the rated voltage within a very tight tolerance, something as tight as +/- 0.24 volts or less. That's 1%, 1 in 100, and I don't see any reason for that sort of control. Two batteries in series will provide from 26+ at full charge to 20 volts or less at discharged. That's all you need for a motor load.

The transformer I suggested is a home brew job. It is not an accurate or precise device, but it is cheap. Not just in-expensive, cheap. Low end, no safetys, no enclosure, usually aluminium windings, but ok for testing. The prinary, at 120 volts, is rated for 6 amps or more. Therefore, the proposed secondary, at 24 volts, will be good for 4 to 5 times that. 24-30 amps.

The bottom line here is that you are dealing with an electric load, not an electronic one. The two are distinctly different fields. Many modern pursuits mix the two indescriminately, often to their and other's, despair. My TV, computer, and stereo are electronic. My machine motors, old ('68 Chev) truck, and most older equipment is electrical. The two are destinctly different. Your project seemsw to fall in the latter.
 
So Ive still been searching for a 24v power supply. We have these battery chargers at work for a 48v vehicle that has different rating on the label for different applications. It shows from 12-60 volts with corresponding amperage.
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I’ve fixed some of these but admittedly don’t understand it like I should. Opening it up I see adjustable mosfets I think? the little blue boxes with screw. I’ve tried adjusting screws and I can change voltage but only down to like 37 volts with adjusting one box. I haven’t been able to figure what the other two do. There is a switch on the side of unit for 110 or 220 which we have set to 110 and my output is 50.4volts. Doesn’t anyone have a clue how to set this unit to 24volts the label looks like it would have 15a which would be close to what I need. Is this the wrong application for a charger? Any thought would be appreciated thanks.
 
The red mark means It's for 50 volts only, lithium polymer batteries. It's not made to have a wide range adjustment- those other numbers are all the different models they make
The blue boxes are trimpots. One is for voltage trim, the others are current limit and so forth
They probably use different transformers for the lower voltage models
 
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This is all very interesting to me because my house and shop run through an inverter from a 24v DC battery bank charged by solar panels and I've never seriously thought much about DC power except for a few lights. I should think more.
 
The bottom line here is that you are dealing with an electric load, not an electronic one. The two are distinctly different fields. Many modern pursuits mix the two indescriminately, often to their and other's, despair. My TV, computer, and stereo are electronic. My machine motors, old ('68 Chev) truck, and most older equipment is electrical. The two are destinctly different. Your project seemsw to fall in the latter.

First off Please do not take my Questions like I'm telling you the answer! My only motive is to gain more Knowledge here and Sentiment is easily lost over the inter-web!

With that said,
Going by your definitions Could this Difference be better described as....
Electronic- TVs, Computers, stereo etc... as Being "Digital electronic components." Where as Electrical- Machine motors, old ('68 Chev) truck, and most older equipment, etc...as being "Analog electronic components?"
 
Thank u. I just know I have something laying around that can do the job. I just don’t know half of what I’m looking at.
I did try using 2 12v batteries I had laying around. They were from emergency lights so they were smaller like motorcycle size. They worked but the motor drained them Pretty quick.
I keep running in to road blocks with every motor I find. To big,wrong direction,to slow,different voltages. It just doesn’t want to cooperate. I’ll get it eventually being cheap has its drawbacks.
 
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