Need help with custom power supply - Page 1
Forum section: electronics / projects

author: jamessinghal
author_rank: Contributor
timestamp: April 18, 2017, 09:53:17 pm
content: Dear all,I need help with powering the DC in on a 50v 15a variable power supply. (http://www.banggood.com/DP50V15A-DPS5015-Programmable-Supply-Power-Module-With-Integrated-Voltmeter-Ammeter-Color-Display-p-1072236.html?rmmds=collection&utmid=1607)I am trying to figure out how to power the input so that I will be able to get almost all of the 50v and 15a power from the power supply.I am also trying to keep just the power solution (excluding the variable converter) under $50 (US).Thanks!

author: rstofer
author_rank: Super Contributor
timestamp: April 18, 2017, 10:28:16 pm
content: I'm no help but I see from the description that the input voltage needs to be at least 1.1 times the output voltage or 55 volts with a maximum of 60 volts.So, since there is no room above the output voltage (merely 5V), the input power supply better be pretty solid at delivering 55-60V at somewhat more than 15A (have to account for efficiency).And then there is the heat... I didn't see a spec for efficiency and that will be a factor for both supplies.Hopefully somebody else will have a recommendation.

author: janoc
author_rank: Super Contributor
timestamp: April 18, 2017, 10:45:45 pm
content: For $50, forget it unless you get extremely lucky on eBay.You need at least 60V/18-20A supply if you want to achieve what you stated. Those sell new somewhere around $1500 or so - and those are industrial switchers for special applications (most industrial supplies top up at 48V).Are you really sure you absolutely need 50V/15A output from that module? If it is for a cheap lab supply, then you likely will never use all those 750W of power. I am also pretty sure that that module will blow up if you actually try to load it to max. That piddly heatsink and fan are ridiculous for that amount of power.Have a look at a high end ATX power supply, those can be around 700-800W and compare the thermal management in those with your module. Also an ATX supply of that rating is upwards of $100 - and that is a mass manufactured product, not a specialist custom thing you are looking for.

author: jamessinghal
author_rank: Contributor
timestamp: April 19, 2017, 01:57:55 am
content: Thank you for you replies,What I am doing is building a custom electronics table, and want to install a power supply into the workbench.I realize that it would be too expensive to get that power supply.I am looking for a good quality way to install a built in variable dc power supply, that wouldn't break the bank.Any suggestions would be extremely helpful.

author: digsys
author_rank: Unknown
timestamp: April 19, 2017, 02:31:40 am
content: First off, I seriously doubt that the unit will deliver what it says. I've bought heaps of various similar moudules, and never found one that even came to within 50% of stated.Even with rebuilds, and added heatsinks, the best I've achieved is ~60% (or 70% short term). IMO, The best (value) high-power DC supplies out there are -www.manson.com.hk/products/category/dc_power_suppliesKPS-6604 1-60V, 0-15AOther than that, if you want to go with those (or similar) modules, Install a decent Variac (handy anyway), an ISOLATION transformer with 2:1 reduction, a big-ass bridge and caps.That way you have a resonable adjustable unregulated DC source as well. Then have a few outputs protected by say polyfuses, for 1A, 5A, 10A max OPs.Note: The Isolation transformer is a MUST !! I run all these options, so not just theory.

author: tooki
author_rank: Super Contributor
timestamp: April 19, 2017, 07:23:14 am
content: Quote from: jamessinghal on April 19, 2017, 01:57:55 amIf you can live with 32V/5A, which covers most uses, then you can use the DPH3205 module, which is the same but is a buck/boost module, and thus can be powered from a cheap 12V power supply and still give you 32V output.

author: janoc
author_rank: Super Contributor
timestamp: April 19, 2017, 08:59:12 am
content: Or simply get a normal linear lab supply. You can certainly find a good quality used one for $50 on eBay, if you can up your budget to about $100 you can get even new ones. Most are 30V/3-5A, that's more than plenty for most of electronics work. If you can afford it, get a dual output one, then you are set even for work with opamps and such.I am rarely ever using more than 12V and 1-2A. 60V/15A supply is a massive overkill that you will almost never use to its full capability when working with electronics. If you later need to power something needing higher current or higher voltage than what your lab supply can manage, it is better to get a dedicated supply for that - e.g. the common ATX supplies or fixed 24V industrial supplies are good for powering various motors that would tax a cheap lab supply.

author: RD Tech
author_rank: Regular Contributor
timestamp: July 31, 2017, 07:34:43 am
content: did you solved the problem?in fact , if you want to output fulload, you can choose a 60V , more than 800W switch power supply. there is not specific brand, because most PSU are ok, now our DPS5015 was updated to very good .when you use 60V , please adjust to under 60V to use , it will be safe, and there is small adjustment at switch ..thank you ,. hope it can help younow we just publish DPS5015 communication , are you interesting?https://www.aliexpress.com/store/product/RD-DPS5015-Constant-Voltage-current-Step-down-Programmable-digital-Power-Supply-buck-Voltage-converter-color-LCD/923042_32702714880.html?spm=2114.12010108.1000023.21.2u7CsDbut for the old one, there is no communication program to support , so there is no way to updated by yourselvesand we just make a video for DPS5015 ripple test, hope it is useful for youhttps://youtu.be/QbcLtOT1IAQ