power supply design (12V, -12V and 5V)

mugzzzzy

New Member

• Apr 19, 2004

• #1

hi,
if any of ya have a design for a power supply that can provide -12,12 and 5v... plz lemme know

ty

 

niq_ro

New Member

• Apr 19, 2004

• #2

use IC LM7805 for 5V, LM7812 for 12V and LM7912 for -12V.. at Imax=1A search for datasheet of this ICs, eg. **broken link removed**

PS: for more power you can use a source AT from a old PC :wink: without more complication just use a bulb lamp 12W/5W at 12V output

 

Sebi

Active Member

• Apr 19, 2004

• #3

The PC supply need load always on 5V output, because the voltage feedback workig from 5V output.

Here is a simple circuit.

 

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• CT_-sup.GIF

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niq_ro

New Member

• Apr 20, 2004

• #4

Sebi said:

The PC supply need load always on 5V output, because the voltage feedback workig from 5V output.

Click to expand...

yes, sorry for my mistake

 

mugzzzzy

New Member

• Apr 20, 2004

• #5

hi.

ty for the helps...by any chance u have the values of the caps??

thanks a lot

 

Sebi

Active Member

• Apr 20, 2004

• #6

Capacitor's value depend from desired load. 2200uF enough for 500..600mA. The decoupling caps are 100nF.Transformer secondary voltage min. 2*7.5V AC.

 

B

biswajit21

New Member

• Feb 20, 2009

• #7

can anyone plz provide me with a circuit dig. for a power supply with 5v,12v and -12v output??

 

House0Fwax

Member

• Feb 20, 2009

• #8

Look at the one posted 4 posts above yours.

 

E

enganwar

New Member

• Feb 20, 2009

• #9

tnx

tanks brater

 

R

roberts26

New Member

• Feb 20, 2009

• #10

Hi,

I am attaching the schematic of a circuit. I need to power up this entire circuit using batteries. Basically i need two sets of voltages, "+-12 V for the opamps and +-6 for the 50Kohm resistor in the schematic.(This is not my design). If anyone has an idea how can I do this I would be very much greatful if you can share that with me. I would really appreciate if you can explain the power circuitry design please.

Thank you.

 

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• 50Hz Notch filter and the subsequent electronics.jpg

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MrDEB

Well-Known Member

• Feb 20, 2009

• #11

remember the regs need 3+v

to operate properly they need 3v higher than your desired voltage.
7812 needs 15v

 

MrDEB

Well-Known Member

• Feb 20, 2009

• #12

heres a sample

of a virtual ground power supply 12+-grd-12-
just add the 7805 and some caps
may need a bigger transformer or in your case more batteries

 

Attachments

• Capture2-20-2009-8.57.07 PM.jpg

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F

fsmyth

New Member

• Feb 21, 2009

• #13

A simple voltage divider on each 12v source should suffice for your
+/- 6v inputs, so you really only need +12v and -12v sources.
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