Do-it-yourself projects and technology updates

12v power supply

Filed under: Circuits Greg Lipscomb on December 18, 2005 @ 9:34 am



There is always a need for a good power supply. Here is a schematic for a 12 volt power supply. Note this could also be done with a 7805 5v regulator, and a “T1 12.6 volt, 1.2 amp ac transformer” . The transformer brings the AC 120v down to around 18v, and the 4-diode rectifier circuit converts the AC waveform to DC. The Cap C1 evens out the ripple out of the rectifier, and the 12v regulator brings the 18v to a constant 12 volts.
[Link]



Here is another schematic that gives both a 12v, and a 5 v power supply. This circuit has a common ground, and has both a +5v, and a -5v regulator, so this could be used to power an opamp where you need these voltages. This would be a good project for that lab powersupply that you need. Anytime one is messing with AC voltage, a person needs to take caution. The fuse in the circuits is very important, and also, these projects should be placed in a plastic project box.[Link]

7 Responses to “12v power supply”

  1. alan Says:
  2. that power supply mod from a pc PSU looks like a damn good idea, especially I have a couple 250-300W ones laying around that are still quite functional.

    about the line following robot. i remember going to the Georgetown Toyota plant tour a few years ago, and they had robotic carts that brought up supplies and what nots to the different lines/areas. I’m almost certain they were line following robots and I was really impressed at the automation. A worker would press a button and the cart would go by itself and little would flicker in its path to alert anyone walking by.

    we don’t have NBME until M3/M4. in those years, some rotations also have house finals. i guess it’s good practice for Step 2, but they are quite hard. anything under a 70 on a final for the M1/M2 years is “not passing” and you have retake a NBME one or retake the test. it’d be nice if things were honors/pass/fail. path/pharm finals were cumulative and evil. altho if I had a say one thing, it’s that knowing good solid path can really impress the attendings for rounds. wish i had known that.

  3. DIY Live » DIY Archive » Ten most needed circuits for the DIYer Says:
  4. [...]   « 12v power supply [...]

  5. bing Says:
  6. i temp built the 12 volt ps and i used a different trans the you said to use and it burnt up , i know now i need to break down and buy the right one my only queston is what can i do to prevent burning up trans again, is their a specific rule of thumb i need to know signed newbie

  7. geoff Says:
  8. im attempting the ps circuit(+- 5v with +- 12v) and i noticed that you didnt specify what the specs are for br1 and br2 assuming the transformers are 2a and 3a respectivly id only assume that the rectifiers are the same specs? could you post and email me with that info

    much appreciated this looks like a killer circuit for my projects and simple enough

  9. dizi izle Says:
  10. wish i had known that.

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  13. Christian louboutin Says:
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