1.5A adjustable regulator — the bench-fit decision
The LM317KCE3 is a three-terminal adjustable positive voltage regulator from ON Semiconductor, delivering up to 1.5A output current with an output range from 1.25V to 37V, set by two external resistors. The 40V maximum input voltage gives headroom for unregulated supplies up to 28V nominal rails, and the 80dB to 65dB PSRR at 120Hz tells you how much mains ripple the regulator rejects — useful when the input comes from a rectified transformer winding rather than a switching preregulator.
Obsolete — replacement planning
Protection and thermal envelope
Built-in protection covers overcurrent, overtemperature, and short-circuit conditions — the regulator folds back current and shuts down before the die exceeds safe junction temperature. The 10 mA quiescent current is typical for this generation of adjustable regulators; it adds 0.5W dissipation at 40V input even with no load, so the TO-220 tab needs a heatsink for sustained output above a few hundred milliamps.