Variable Power Supply With LM7812

audioguru2

Apr 6, 2004
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Apr 6, 2004
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12,026
This new project is here: http://www.electronics-lab.com/projects/power/026/index.html

It has some serious errors:
1) It says and shows LM7812 but it links to the datasheet of an L7812 that is different.
2) It does not say its adjustment range of output voltage.
3) The datasheets of the L7812 and LM7812 show that its output voltage range will be from 12V to 314.7V which is ridiculous.
4) The current is 54mA in its little trimpot which will burn it badly when its resistance is turned down.

The IC should be an LM117 or if R1 is changed to 120 ohms then an LM317 can be used.

View attachment 42040

 
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