LM317 voltage regulator R2 is getting very hot? why?

calvingloster:

123Splat:
E/R= I
IIR=P, not IRR

Can you please talk in words and not letters? I don't know what you trying to say?

A person needs to know a little algebra and common variable names to be successful in this hobby. Do the substitution yourself, E = voltage (or you can use V), I = current, R = resistance, P = power.

Heat dissipation is Amps multiplied by resistance.

No, power (heat) is volts times amps. Or: P = V * I

With a little algebra (you passed algebra?), we also have P = I2 * R and P = E2 / R

Very useful and essential formulas, should be memorized. Used properly, they are guaranteed to prevent that burning smell :wink: