Abstract: A tester and method for testing a rectifier-regulator. A ramping voltage generator generates a ramping input voltage during each of a multiplicity of ramping cycles in response to ramping voltage control signals provided by a controller. A relay circuit relays the ramping input voltage to one of the input terminals of the rectifier-regulator during each ramping cycle in response to relay control signals provided by the controller. The rectifier-regulator provides in response a ramping output voltage at its output terminal during each of the ramping cycles. A voltage measurement circuit makes voltage measurements during each of the ramping cycles representing the ramping output voltage. A trip point determination circuit determines when the trip point of the rectifier-regulator occurs during each of the ramping cycles and generates in response a trip point signal during each of the ramping cycles indicating that the trip point has occurred.