DC-DC variable voltage and current lab power supply

B

bengaltiger

New Member

• Jul 31, 2012

• #1

Hi,

looking for simple DC-DC variable voltage and current lab power supply circuit.

variable voltage (around 3 to 12 volts) and variable current. (current limiting with LED indicator)

Also I will add digital voltmeter and ammeter module.

Regards,
BT

 

magvi

Member

• Jul 31, 2012

• #2

use lm 317 regulator ics, Google it.. you will be amazed with the results.!

 

K

KeepItSimpleStupid

Well-Known Member

Most Helpful Member

• Jul 31, 2012

• #3

You did fail to mention the current range of interest.

 

S

simonbramble

Active Member

• Aug 1, 2012

• #4

have a look at the LT3080 datasheet. Lots of application circuits including a lab power supply. Also you can adjust this down to 0V, whereas with most regulators they only go down to 1.2V:
https://cds.linear.com/docs/Datasheet/3080fc.pdf

 

B

bengaltiger

New Member

• Aug 1, 2012

• #5

thanks for the replies.

Current 100ma to 2 amps


I need LED indicator when current over limit occurs.

BT

 

P

picbits

Well-Known Member

• Aug 1, 2012

• #6

What is your input voltage ?

 

B

bengaltiger

New Member

• Aug 1, 2012

• #7

12v and current max 2amps.

 

P

picbits

Well-Known Member

• Aug 1, 2012

• #8

You'll need either a switching regulator or low dropout regulator if you want your output voltage to swing to your input voltage.

Also bear in mind that if you have a 2 amp load with 12 volts input and 3 volts output you'll be dissipating around 18 watts of power so you'll need a reasonable sized heatsink if you're going for a linear regulator.

 

K

KeepItSimpleStupid

Well-Known Member

Most Helpful Member

• Aug 1, 2012

• #9

This regulator uA723 http://www.datasheetcatalog.org/datasheet/texasinstruments/ua723.pdf has been around for years.

**broken link removed**

**broken link removed**

**broken link removed**

http://www.electronics-lab.com/projects/power/004/index.html

**broken link removed**

http://www.spaennare.se/psupply.html

and lots more, I'm sure. Google "723 power supply"

 

B

bountyhunter

Well-Known Member

• Aug 1, 2012

• #10

bengaltiger said:

Hi,

looking for simple DC-DC variable voltage and current lab power supply circuit.

variable voltage (around 3 to 12 volts) and variable current. (current limiting with LED indicator)

Also I will add digital voltmeter and ammeter module.

Regards,
BT

Click to expand...

Here is a design for a good lab supply that swings the output voltage down to zero and has adjustable current limit level. LED indicates when in current mode.

 

Last edited: Aug 1, 2012

K

KeepItSimpleStupid

Well-Known Member

Most Helpful Member

• Aug 1, 2012

• #11

At this price, I'd buy one: **broken link removed**

 

B

bountyhunter

Well-Known Member

• Aug 1, 2012

• #12

Me too, but nobody ever listened when I gave that advice so I stopped giving it.

 

Last edited: Aug 1, 2012

B

bryan

Member

• Aug 14, 2012

• #13

Thought about building this.

http://tuxgraphics.org/electronics/200707/bench-power-supply-unit.shtml

 

B

bengaltiger

New Member

• Aug 15, 2012

• #14

thanks bryan. looks interesting and informative.