EEVblog Electronics Community Forum

Products => Test Equipment => Topic started by: aparlett on March 28, 2013, 12:45:10 pm

Title: Power Supply
Post by: aparlett on March 28, 2013, 12:45:10 pm

Hey Guys

Looking for a cheap power supply that has +/- output round $100 mark? nothing too high powered just to play around with precision op-amps.
any suggestions will be a great help.

thanks

Title: Re: Power Supply
Post by: eevblogfan on March 28, 2013, 12:53:12 pm

hey

Why dont you use cheap ass 12~ 30V 9W or so wall wart and use voltage splitter creating virtual ground using Lm358 one pot and pair of NPN and PNP power transistors ?  I don't have the schematic now  :palm:

pleas some one give him the proper schema  :scared:

all I can find now is that ( should be good anough as op amp baiasing supply )

http://www.circuitstoday.com/wp-content/uploads/2008/08/voltage-splitter-using-opamp.JPG (http://www.circuitstoday.com/wp-content/uploads/2008/08/voltage-splitter-using-opamp.JPG)

Cheers :)

Title: Re: Power Supply
Post by: IanB on March 28, 2013, 12:56:28 pm

If you only need a few milliamps than back-to-back 9 V batteries will work fine.

Title: Re: Power Supply
Post by: aparlett on March 28, 2013, 01:00:53 pm

Im going to uses two 9 volt batteries for now but would like to have a proper supply as im going to be suing it alot more in the future.

Title: Re: Power Supply
Post by: eevblogfan on March 28, 2013, 01:21:57 pm

hey


Schema is the first photo and the final circuit I've built ( including Lm317 , but not really needed I think ><" )

Title: Re: Power Supply
Post by: aparlett on March 29, 2013, 05:34:37 am

thanks that looks pretty good to get me through until i can get a better supply

Title: Re: Power Supply
Post by: aparlett on March 29, 2013, 05:43:49 am

any suggestions as off the self ones i can start looking into as well or are they out of price range

Title: Re: Power Supply
Post by: eevblogfan on March 29, 2013, 09:16:43 am

I am afraid the "good " one ( e3630A) is out of range unless you can get it locally for that 100~120$ ( which I don't think you can , but give it A chance :P )

I don't know any other +/- supply to recommend though I am absolutely sure there are few more out there :P