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Two LM317 voltage and current controllers

A while back I discovered the versatility of the LM317 chip - it can control voltage in one configuration and current in another. Whilst a switching voltage regulator would be great for efficiency, the linear regulator such as the LM317 provides lovely steady power. So soon I'll be building a power supply that includes a switching regulator to take the voltage down to a couple of volts more than needed (thus giving great thermal efficiency) and then uses two LM317 chips working together to provide the smooth voltage and current required.

From the data sheet here is the voltage regulator circuit.

And here is the current regulator circuit.

Testing the LM317 as a voltage regulator

Testing the LM317 as a current regulator

Finally I grabbed a 32V AC-DC adapter, plugged it in to a cheap power supply module and then into the breadboard with the LM317 twins configured first for voltage and then for current.

When the buck converter arrives I'll pop it, the LM317s and some other bits and pieces into a nice box and have a pretty nifty bench power supply.