Bench power supply advice

[darren adcock]

Hi All. Not been on here for a quite a while as lost my workshop and ongoing back issues are causing me to change the way I work.

Anyhow, I've made a small area in my flat and am in need of getting a smaller in size bench power supply if one exists, also with ongoing back problems the lighter the better, but smaller is priority?

At the minute I'm using a Rapid electronics DC HY3002-3 - "The Rapid HY3002-3 is a Digital Triple Output Bench Power Supply. This power supply has three independent output channels: two of them provide adjustable output of 0-30V and 0 to 2A, while the third has a fixed output of 5V DC 3A"

Dimensions are; Width 260mm, Lenght 315mm, Height 155mm

https://www.rapidonline.com/rapid-hy3002-3-triple-output-bench-psu-led-2x0-30v-0-2a-1x-5v-3a-85-1921

I run it in dual rail configuration for -12v/ 0 / +12v... it would be good to have the option to run at -15v / 0 /+15v also but not essential

Also defo need, short circuit protection/current limiter/reverse polarity protection


I've had a look around but thought I'd ask here as figured there might be recommendations from folk who have experience of specific models... money isn't too much of a problem as it will be an investment so i can carry on building.

I've still not had a chance to finish my PSU whch you guys were helping me with, I've decided to start again with a ready made alluminium case to make sure there are no bends/strained wires which I could forsee being a problem further down the line, I hopefully will be redoing that project around the middle of May, and will post in the thread.

Thanks in advance

Darren

 

[kellys_eye]

Dimensions are; Width 260mm, Lenght 315mm, Height 155mm

That's pretty compact for what it is already. I doubt any space you save from getting a smaller one would make much difference to your working space.

If I had the 'spare' cash to purchase a smaller PSU I'd use it to purchase another (vital?) piece of test equipment and/or put it towards the cost of a better 'scope for example.

 

[kellys_eye]

Here's an idea..... build a small box containing a couple of LM317's - one to regulate voltage and one to limit current. Fit one of those cheap dual V/I digital displays and fit a power socket on the rear - an INPUT power socket.

In this way you can plug in any old wall wart, laptop PSU or spare power pack you have lying around and get a simple variable DC PSU with current limiting in a VERY small box.

 

[darren adcock]

Cheers

I suspected as much in terms of spec and size, thanks for replying

I don't quite know how to achieve as you suggest with using LM317's but will do my own research as suggested

best

Darren

 

[kellys_eye]

The LM317 data sheet shows how to configure the device as both a voltage regulator and current limiter. The very low component count makes the solution very simple (and quick) to implement - a bridge rectifier, smoothing, two extra capacitors and two resistors - ta dah..... Robert's your mother's brother.

A variable (1.25 to 30V if you want) PSU with 0-1.5A current limiting (needs an extra LM317 and resistor).

 

[darren adcock]

Great, cheers

Will begin looking into this today

Darren

 

[Chemelec]

Or you could use an LM350 for a Higher Current rating.

 

[darren adcock]

Thanks Chemelec, will look at this also