DSE q1770 PSU - Page 1
Forum section: electronics / beginners

author: Chopsticks
author_rank: Regular Contributor
timestamp: June 17, 2012, 02:13:55 am
content: I was going past dick smiths yesterday and on a whim i went it to see if they had any of those $49 bench psu's left and sure enough there was one sitting on the back of a top shelf gathering dust. fantastic i thought so i bought it and took it home, worth nothing there may still be some of these units floating around if anyones keen to go looking.Anyhow the only issue i have with it so far it that the voltage dial is extremely sensitive as such say im setting it to 5vdc just the slightest movement can increase/decrease that voltage very quickly, so i was wondering if theres a way to somehow change the pot value etc so that its easier to select a voltage, in a perfect world it would have had a rotary encoder in it though i doubt thats a possible mod as im sure the current circuit relies directly on the current pot to adjust resistance etc...Anyone got one of these units and have any ideas?

author: Rerouter
author_rank: Super Contributor
timestamp: June 17, 2012, 02:15:21 am
content: rip it open, find out its value and throw money at a 5 or 10 turn potentiometer,

author: Chopsticks
author_rank: Regular Contributor
timestamp: June 17, 2012, 02:40:24 am
content: i dont know why i didnt think of multi-turn pots...thanks mate

author: BradC
author_rank: Super Contributor
timestamp: August 11, 2017, 09:02:21 am
content: Holy thread revival batman.I have had one of these power supplies for years now (and for the record I love it). The voltage pot is a 50K linear.I just finished replacing it with a 5 turn wirewound. RS Part No 460-1950. Because the pot is 22mm you need to remove the top PCB standoff adj the voltage pot to get it to fit. I made a steel washer to sit behind the panel and modified the existing voltage knob to fit. It's not as pretty as it was, but 6V/turn is easier to get control of than 30V across 240 degrees.

author: Muttley Snickers
author_rank: Unknown
timestamp: August 11, 2017, 09:58:01 am
content: Forty bucks a pot, I agree that other than the shit house potentiometers Manson used in these units they are actually not a bad little supply and do the job for most of the lighter tasks, I have two of them and they are probably my most frequently used supplies and have been for many years. I found when the original controls start to fail just the act of touching the outside case of the supply would cause the output to vary dramatically, I was hunting a ten turn 50k for these without any luck but that five turn 50k pot should do nicely.

author: BradC
author_rank: Super Contributor
timestamp: August 13, 2017, 05:01:02 am
content: Quote from: Muttley Snickers on August 11, 2017, 09:58:01 amI gave up buying cheap E-bay components years ago. Yeah its 40 bucks, but I know it's legit, quality and reliable. Free delivery and it was on my door step in 5 days.I buy most of my stuff through RS these days unless it's not critical where I get it from Altronics.The 5 turn gives me vaguely 6V/turn and is considerably better for fine control than the technique I developed using my fingernail to knock the serrations on the voltage pot to get fine(ish) control.

author: wilfred
author_rank: Super Contributor
timestamp: August 13, 2017, 05:55:22 am
content: I only paid $49 for mine. Putting a $40 pot in it seems like over capitalising.