Need Protection circuit for DC-DC Buck Converter - Page 1
Forum section: electronics / beginners

author: ommsiva
author_rank: Regular Contributor
timestamp: September 06, 2024, 03:03:49 am
content: Hi to all,Previously I constructed building 0-30V , 0-10A regulated power supply using 24V-0-24V @10 A transformer, I failed many times by building circuit using Linear Ics and current boosting technique.Now have purchased 300W 20A DC-DC Buck Converter Step-down Module but it does not have any protection circuit.I have attached the module , Kindly give some ideas and circuit for protecting the module which we can anticipate while using as a lab bench power supply.Thank you all.

author: perieanuo
author_rank: Frequent Contributor
timestamp: September 06, 2024, 05:12:54 am
content: hi, i seriously doubt that thing will be a LAB!!! power supply. no offense, you need to reconsider this

author: Phil1977
author_rank: Frequent Contributor
timestamp: September 06, 2024, 08:39:18 am
content: Don't get me wrong, DIY of a generic lab power supply may be very educational and for some nerds it´s even great fun.But in times when you get a quite robust 30V/5A lab supply for <$50 with housing, displays and basic protection functions I would always recommend to buy such a thing. Even if you can DIY something much better or more powerful, it´s always convenient to have such a basic supply available.(And before the China-Bashing starts again: No one can expect a $50 lab supply to be really good. But it often is much better than having no power supply)

author: Picuino
author_rank: Super Contributor
timestamp: September 07, 2024, 09:25:06 am
content: What model of cheap Chinese power supply would be a good choice?I have a MLINK PPS3005 (programmable linear 30V 5A power supply).

author: perieanuo
author_rank: Frequent Contributor
timestamp: September 09, 2024, 09:40:38 am
content: Quote from: Picuino on September 07, 2024, 09:25:06 amexactly, this is some real good advice, starting analog for psu regulation and microprocessor for set U/I.that kind of psu is also branded by Konrad if i remember well and it's one of my preferred approach, me personally i build another linear psu and another microprocessor control, but the main line linear regulation will teach op the basic mistakes ang goto's, the processor part to be eleganttuning some dcdc already-made especially for big currents may not even be possible in the first place without major modification on feedback part, so i say no very loud. even experienced guy in electronics may smoke the psu in this scenario, usually those big amps psu's have a tight voltage regulation loop, you cannot make them from 0 to 24-30V easily without very good understanding, that's not for beginnersbr, ovidiu

author: Phil1977
author_rank: Frequent Contributor
timestamp: September 09, 2024, 10:09:51 am
content: The linear supply for around 100€ is a really good offer.For around 50€ you can also get a lot of different SMPS lab power supplies. If you use them to charge batteries or power larger DC loads like motors or other power converters then their regulation quality and ripple is usually no problem.I have one from Peaktech which has very decent build quality and even a linear post-regulator and one from Wanptek. Both have no obvious safety faults like non connected PE, obviously bad transformers or too small creepage distance. But of course I can not speak for all the offerings from Asia, there are for sure also devices with bad quality available.

author: ommsiva
author_rank: Regular Contributor
timestamp: September 10, 2024, 07:10:48 am
content: Here is the circuit. Review this and provide necessary protection for this module.Thank you all.

author: ommsiva
author_rank: Regular Contributor
timestamp: September 12, 2024, 04:55:43 pm
content: Here is the datasheet.

author: ommsiva
author_rank: Regular Contributor
timestamp: September 13, 2024, 12:36:28 am
content: Here is the datasheet of dc-dc buck converter.

author: Phil1977
author_rank: Frequent Contributor
timestamp: September 13, 2024, 06:08:30 am
content: Repeated postings can not change that obviously no one wants to support the idea to make a lab power supply from a LED driver. This is like turning your lawnmower into a motorbike - yeah of course it´s possible. But would you recommend it to someone who doesn't have experience? - better not!If you want the cheapest lab power supply you can find: Go for such a 50$ SMPS or go for some used linear power supply.If you want to learn about DC-DC converters and their limits: Then go in small steps, e.g. ask what´s the difference of the current regulation of a LED driver to the current regulation of a lab power supply. The more precise your question is the higher is the chance of a qualified answer.

author: ArdWar
author_rank: Frequent Contributor
timestamp: September 13, 2024, 06:48:37 am
content: Is that schematic even correct? The bootstrap doesn't even look right.