LM317 question

[Oh_Discordia!]

Working on a compressor pedal that calls for an LM317 and it indicates a TO220 package (the board has room for it). I ordered a few LM317's that are TO92.

Ok to use?

Here is the doc:
GCI Compressor

 

[Bricksnbeatles]

its regulating down to 4.5v based on those resistor values. if you're only inputting 9v then you're not generating enough heat to require a heatsink, so the TO92 should be absolutely fine

Constant Voltage Regulator

www.ef-uk.net

 

[Oh_Discordia!]

Awesome! Thank you!

 

[Chuck D. Bones]

The rule of thumb is under 200mW -> no heatsink req'd

The load current is all flowing thru the programming resistors (R14 & R15).

Iload = (Vo - Vadj) / R15 = 1.25V / 150Ω = 8.33mA

Pdiss = (Vin - Vout) * Iload = 4.5V * 8.33mA = 37.5mW

You're good to go.

BTW, that compressor is the same as the Engineer's Thumb except for one extra knob. That extra knob is unnecessary because VOLUME & GAIN do the same thing. Don't set THRESHOLD below noon or you'll get distortion.

 

[Oh_Discordia!]

The rule of thumb is under 200mW -> no heatsink req'd

The load current is all flowing thru the programming resistors (R14 & R15).

Iload = (Vo - Vadj) / R15 = 1.25V / 150Ω = 8.33mA

Pdiss = (Vin - Vout) * Iload = 4.5V * 8.33mA = 37.5mW

You're good to go.

BTW, that compressor is the same as the Engineer's Thumb except for one extra knob. That extra knob is unnecessary because VOLUME & GAIN do the same thing. Don't set THRESHOLD below noon or you'll get distortion.

Thanks for the calculations Chuck! Hoping to wrap it up tonight - I'll keep the threshold tip in mind.