Wattage in voltage devider

ISB123

Joined May 21, 2014
1,236
0.33uF are electrolytic.
In case your circuit that is hooked up to the 7805 draws 1A and you don't have a heatsink it will go in thermal shutdown mode.
 

Thread Starter

Chillum

Joined Nov 13, 2014
546
Hopefully it has sunk in by now that you do not use a voltage divider as a power supply.

But what is a regulator really? A regulator is a voltage divider with the regulator replacing the top resistor and the load replacing the bottom resistor. But the magic of it is that the resistance of the regulator changes to automatically keep the same voltage on the load.

Bob
Thanks Bob! It is magic, massively cool! it has sunk in, and as I said earlier, its cheaper too, now I only need to know about those capacitors, electrolytic/ceramic
 

Thread Starter

Chillum

Joined Nov 13, 2014
546
To be redundant (more heatsink than minimum), what watt heatsink? And do I have to drill a hole in the heatsink, I only have a hand drill-- for veroboard breaks
 

alfacliff

Joined Dec 13, 2013
2,458
if you use an lm323k or 74h05 you can get much more current, the lm 323k runs 2 amps, and the 74h05 runs 3 amps. otherwise the same circuit.
 

ISB123

Joined May 21, 2014
1,236
You can make it like this:
C3-100 uF
0.1uF cap need to be ceramic(non-polarized)

Corrected the mistake.
 
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Thread Starter

Chillum

Joined Nov 13, 2014
546
You can make it like this:
C3-100 uF
excuse my ignorance, but what is C3's unit? then its C1,C2 0.1uF ceramic but what happens to ground, on the circuit i referred to have GND connected to the Caps EDIT: misread soz
 
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studiot

Joined Nov 9, 2007
4,998
The pipe theory (smallest pipe determines current) and load may use any amount of the pipe
Forget the pipe theory.
Whoever proposed it was probably smoking weed in that pipe!

You have several 12volt power supplies.

They are like batteries, they maintain 12 volts across their output terminals, so long as the current drawn by the load is within the supply specification limits.

This is exactly the same as the mains outlet on your wall.

A fan heater draws (say) enough current to provide 1kilowatt, the mains voltage remains constant, the current alters so the power which equals voltage times current is 1kW.

A table lamps draws a different current, enough to supply say 0.04 kW.

For a given supply, The current draw is determined by the load. Period.

This is what I meant earlier by understanding the basics.

Once you can confirm you are happy with this we can proceed.

I have one or two comments about your digital circuitry and providing a 5V or other supply from your 12V one. There is a better solution that a 5V regulator.
 
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