The HRS Regulator was the first Marlec regulator to incorporate electronic Pulse Width Modulation (PWM) technology to regulate battery voltage to prevent overcharge. This generation of voltage regulation saw the end of the need for bulky heat sinks to dissipate excess energy generated by the windcharger and, more importantly for the lifetime of the windcharger, introduced speed limiting to the turbine when the battery is full.
The HRS503 is designed for use with the Rutland 504 and previous Rutland 503 models, as well as solar panels up to 100w.