The 1N4001 in parallel with Rx protects Rx and U2’s ADJ pin if U2’s over-temp or over-current shutdown feature kicks in. That would leave U1 trying to shoulder the whole load, dropping enough voltage ...

Investigating potential power current sources capable of handling both AC and DC currents using the LM317 current source.

At first glance, [RobBest]’s constant current source looks old school. The box is somewhat old-fashioned, featuring switches and binding posts. Most importantly, there’s a large analog … ...