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Saturday, September 21, 2013

LM7805, LM7806, LM7808, LM7809, LM7810, LM8012, LM7815

   LM7805 is voltage stabilizer, 7805 define what is output voltage in this case it's +5V. Otherwise there is a lot of voltage stabilizer like 7806, 7808, 7809, 7810, 7812, 7815 etc. in each 78XX the last two digit define output voltage. I recommend that max input Voltage is not over 10V higher than nominal value in this case if we use lm7805 -->max input V is 15V. Can you put input over 15V? Yes, of course but then lm7805 will heating more and you have bigger dissipation. Let's see an example if you connect 20V on lm7805 with 2A that is P=15V*2A that is 30W which lm7805 must dissipate. So in order to avoid overheated you have to put bigger COOLER -->instantly bigger space, bigger device etc. 

  They could be in different package: TO-3, TO-220, SOT etc so when you creating schematic you should consider which one will you use.


How to connect LM7805

C3,C4 are here to reduce bumps of VOLTAGE it's usually about 100nF




**When it's about Power supplies it good practice to put diode before input because if you accidentally, forget the where is + and Switch polarity that + is on the - the diode is impermeable polarized and the circuit will never close and your Integrated circuit (IC) will be alive instead without diode if you switch polarity your circuit is done! It's easy to connect just Anode(+) must be on +12V

How it looks like with diode:





Here is datasheets for all lm78XX which i mentioned before.

LM78XX DATASHEET




That's all about LM78XX, I hope that will be helpful!
For week or two when I'll get some free time I'll make video about what i write above. :)



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