12v power supply to 24v - Page 1
Forum section: electronics / repair

author: daniel818a
author_rank: Contributor
timestamp: January 06, 2022, 01:39:09 pm
content: hi i need a power supply that gives 24v and 1 ampgot 12v and 2.5A and i dont want to use convorteralrady changed the caps from 25v to 50this is data sheet for schottkyhttps://www.onsemi.com/pdf/datasheet/mbr20100ct-d.pdfTY FOR THE HELP![ Specified attachment is not available ]

author: Haenk
author_rank: Super Contributor
timestamp: January 06, 2022, 01:48:22 pm
content: IMHO the easiest solution is to dump this 11 year old shady PSU (pretty shitty unit) and spend 10 bucks for a new one.

author: daniel818a
author_rank: Contributor
timestamp: January 06, 2022, 01:50:48 pm
content: Quote from: Haenk on January 06, 2022, 01:48:22 pmand the hard one>?

author: tunk
author_rank: Super Contributor
timestamp: January 06, 2022, 01:52:22 pm
content: No expert on this.U3 could be a TL431 - get an understanding of how thisworks, and then reverse engineer the circuit around it.A change from 12 to 24V probably isn't recommended, youmay stress the PSU beyond it's design limits and it mayblow up.

author: Haenk
author_rank: Super Contributor
timestamp: January 06, 2022, 02:28:14 pm
content: Quote from: daniel818a on January 06, 2022, 01:50:48 pmWasting 2 hours of your life peeling off the silicone, *then* throwing it away.(It *is* a shitty unit, and an old one, so I would not waste a minute on this. I think I recently paid about 11 EUR shipped for new Meanwell 24V framed PSUs.)

author: madires
author_rank: Super Contributor
timestamp: January 06, 2022, 02:32:32 pm
content: In most cases the output voltage of a simple flyback converter can be changed by about 20% without causing problems for the PWM controller, flyback transformer and other parts. For +100% you would have to replace also the flyback (twice the secondary windings).

author: acheaile
author_rank: Newbie
timestamp: January 06, 2022, 02:34:45 pm
content: I think you need to change the transformer to achieve this. Not only that, you'll probably need to redesign the opto circuitry. The small transfo. might cost you 12$ alone.The step up converter is one of the solution but you dont want to go that way, so as someone else said, buy another 24vdc smps for quite cheap...

author: rh1
author_rank: Newbie
timestamp: January 06, 2022, 05:36:58 pm
content: Another option, if you have another 12v supply then you *can* put them in series. This works because at least one is ungrounded (otherwise one will be shorted out). Note that both supplies should be powered on at the same time, but because they still don't start simultaneously one will receive the -12v from the other supply momentarily (depending on your load). So a diode over the supply would be nice. Note: this is a *very* sketchy method.

author: abdulbadii
author_rank: Frequent Contributor
timestamp: January 06, 2022, 11:28:39 pm
content: OP's haven't told whether it's linear or SMPSif SMPS, forget such the replacement, can't be done that simple as it's nothing to do in raising V output

author: ambrosia heart
author_rank: Regular Contributor
timestamp: January 07, 2022, 01:53:47 pm
content: Quote from: daniel818a on January 06, 2022, 01:39:09 pmHow to do?see photos 1-2 and pm.

author: madires
author_rank: Super Contributor
timestamp: January 07, 2022, 02:15:23 pm
content: Quote from: abdulbadii on January 06, 2022, 11:28:39 pmActually he did, by posting pictures of the PCB.

author: madires
author_rank: Super Contributor
timestamp: January 07, 2022, 02:22:17 pm
content: Quote from: ambrosia heart on January 07, 2022, 01:53:47 pmWhy don't you post the answer here?

author: TheMG
author_rank: Frequent Contributor
timestamp: January 07, 2022, 06:04:13 pm
content: I have a whole bin full of decent 24V 2.3A SMPS I would give you a couple but the cost of shipping is likely to exceed what you could buy a brand new one for from a reputable seller.As said already, converting one from 12V to 24V would require disassembling and re-winding the transformer secondary, in addition to componentry changes on the secondary side and feedback loop. Far more effort than it's worth and you risk destroying the transformer in the process. Go ahead and do it if you just want to do it as a challenge and learning opportunity, but otherwise it's definitely not practical.