What is the Best Voltage Regulator for a Dual Polarity Power Supply?

[elecz]

I want to make a power supply which gives DC voltage from -17V to +17 volt, i.e of both polarities. Someone please tell me which voltage regulator is easiest and most appropiate to use? Thankyou!

 

[JimmyAlz]

Easiest would be to generate a "fake" ground at +17V and then find a regulator that can do 0 to 35V. What I mean by that is that you should keep the power supply isolated from ground and then connect the case ground to the +17V output of your power supply.
Search digikey.com (US) or farnell.com (Europe) for a 35V capable regulator.
An LM317 for instance would give you -15.8 to +17V connected that way. Close but not quite.

 

[JimmyAlz]

I was a bit unclear ... you will need two regulators: one adjustable 0 to 35V and one fixed or adjustable set to +17V.

 

[elecz]

Ok thankx.. But I want to know exact device name. e.g LIM117, I want to know more...

 

[vk6kro]

Mitsubishi have dual tracking regulators like this:

http://monopoly.highspies.com/pdf/m5230l.pdf

There are circuit diagrams in that data sheet. Note that high current outputs can be obtained by adding power transistors.

You would need a transformer that gives 30 volts centre tapped. If you ground the centre tap and use a bridge rectifier, this will give +/- 21 volts after filtering.



If you preferred to get individual regulators, you could use the LM317 for the positive output and a LM337 for the negative output.

There are lots of regulator circuits here:
http://www.hobbyprojects.com/V/voltage_regulators.html

 

[elecz]

Thanks a lot! You have solved my big problem...