Would this be a suitable bench power supply? - Page 1
Forum section: electronics / projects

author: Cykar
author_rank: Contributor
timestamp: January 22, 2021, 08:46:29 pm
content: I dont have a bench power supply, having never felt i could justify the cost for the small amount of electronics i do, and not really having any spare cash. But occasionally i rummage thru eBay just to see what is around. This time, i found this:https://www.ebay.co.uk/itm/Labnet-International-PEQ-Power-300-Electrophoresis-Power-Supply/293966093981?hash=item4471be9e9d:g:Uw8AAOSwfW1gCYThA PEQ Power 300 power supply, clearly intended for a specific system, but sometimes i come across things like this which i wonder whether or not they could be repurposed as a general bench power supply.I haven't had much time to dig into the details, but from from what i read, it can supply 5V to 300V, have its current limit set and even have the wattage set. I think the voltage can only be set in increments of 1 rather than something more detailed, but compared to a cheap £40 Chinese power supply, i just wondered what people thought about this.

author: calzap
author_rank: Frequent Contributor
timestamp: January 22, 2021, 08:54:34 pm
content: This is a high voltage, low current supply and not suitable as a general bench supply. BTW, it can deliver a lethal shock.Mike in California

author: ledtester
author_rank: Super Contributor
timestamp: January 23, 2021, 01:54:15 am
content: Also, as a protection measure many of these kinds of supplies require a minimal load resistance.

author: Cykar
author_rank: Contributor
timestamp: January 23, 2021, 11:48:34 am
content: Interesting. Thanks for the info.

author: wizard69
author_rank: Super Contributor
timestamp: January 24, 2021, 03:25:07 am
content: Quote from: Cykar on January 22, 2021, 08:46:29 pmHaving been in similar tight money situations I really don't see power supplies to be a smart use of your available money. I don't want to dismiss the utility of a bench supply(s), on an active bench but you can get by with other power solutions easily. It would be better to invest your money in quality tools when you can afford them. A good multimeter or two, a soldering station and other soldering tools, good hand tools and etc. I'd even consider a scope before a power supply in most cases.QuoteYou need power supplies that operate in a voltage range that are common for the projects you are interested in. This one would likely never cover your needs.QuoteYou would be far better off searching the used electronics market for a quality bench supply if you want to save money. You would save even more DIY'ing a supply or two for your needs. The third option is to salvage a supply out of some electronics based device.

author: james_s
author_rank: Super Contributor
timestamp: January 24, 2021, 04:17:44 am
content: When I was a broke kid I got by for a long time using scrounged "wall warts" and power supplies built out of scavenged parts. They're not as good as a real bench supply but they'll do the job in a pinch.

author: Someone
author_rank: Super Contributor
timestamp: January 24, 2021, 07:34:00 am
content: Plenty of cheap old bench supplies:https://www.ebay.co.uk/itm/Farnell-E30-1-Bench-Power-Supply/133644412896?epid=6009067774&hash=item1f1dd3e7e0:g:6SQAAOSwJ1NgCiROTry to find something thats local pickup. Farnell E30/L30/LT30 etc seem to be perennially available at the "junk" end of the market, but other brands pop up for similar low prices as they are so large and heavy and few people want to pay postage/shipping.

author: Mark
author_rank: Frequent Contributor
timestamp: January 24, 2021, 09:15:41 am
content: Not suitable for general usage as a bench supply. I have a couple of 3kV supplies and a few 200V electrophoresis supplies and as mentioned already they have requirements for minimum current. I use the 200V supplies for testing DCDC converters but they will switch off if a rapid change in load is detected.The electrophoresis supplies can also be noisy (on the output voltage AND fan noise).