EmmienLightFan Posted June 25, 2015 Share Posted June 25, 2015 Can I connect two 15vdc laptop power supplies in series to get 30volts? The internet says this is fine but some say you need both to be above the required load and you need identical PSUs. Does anybody know anything and is it OK to just connect them up and try? Link to comment Share on other sites More sharing options...
dgrant Posted June 25, 2015 Share Posted June 25, 2015 Its possible however personally, I wouldn't recommend it. I think possible voltage conversion, frequency and noise issues during the rectification and filtering process, might create issues as I don't think there are any two identical power supplies, actually identical in every small detail. There will probably be some small variances. Whether this would end up causing a problem, I'm truly not sure but I wouldn't risk it myself. Why not just obtain the correct power supply at the correct voltage and current rating needed for the application, then not have to worry? Link to comment Share on other sites More sharing options...
EmmienLightFan Posted June 26, 2015 Author Share Posted June 26, 2015 A 30 volt regulated PSU of about 3-5amps is really hard to find. I found a 30v printer one wjich was 300ma, and one which was over £100!!! Link to comment Share on other sites More sharing options...
dgrant Posted June 26, 2015 Share Posted June 26, 2015 There are precision adjustable power supplies that should work although they might be a bit pricier and unknown if you can get them over there. I've worked with DC power supplies where some are ranged from 0-35 volts and others that are 0-125, 0-250 and so on. They aren't cheap and all had the ability to run off 240vac as well as 120vac. Again, not cheap. Link to comment Share on other sites More sharing options...
Max-Paul Posted June 28, 2015 Share Posted June 28, 2015 dgrant,now if he was to put them in parallel I could see your concerns. Maybe I am missing something, but when in series I cant see any problem with a D.C. current. If anything the noise might even be nulled. Not saying that it could not be amplified, but there is that chance that it might be nulled also. In a nutshell I would say go for it. As long as it is in series. Now just to make sure that it is understood. The voltage will add (V1 + V2). But the current will only be as high as the lowest current rated supply. Example one supply is capable or .5A and other is rated at 1.0A. The best you could hope for is .5A to your lights. Link to comment Share on other sites More sharing options...
dgrant Posted June 28, 2015 Share Posted June 28, 2015 I was concerned about residual noise from the rectification and filtering process. True, not sure it would impact him or not. The power supplies that would solve this, are quite expensive so going the cheaper route and give it a try, might be the best option. My knowledge-base on the good supplies would be TCR Lambda's...expensive. Link to comment Share on other sites More sharing options...
Darryl Lambert Posted June 29, 2015 Share Posted June 29, 2015 I think EMF is going a different route. Link to comment Share on other sites More sharing options...
Max-Paul Posted June 29, 2015 Share Posted June 29, 2015 was that by chance supposed to be ELF? Link to comment Share on other sites More sharing options...
Darryl Lambert Posted June 29, 2015 Share Posted June 29, 2015 Yup. Me bad. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now