An electronic circuit used to maintain a level amount of voltage in an electrical line. It eliminates power surges, spikes and brownouts, which can cause harm to sensitive electronics. A voltage regulator "module" (VRM) is a voltage regulator in a replaceable unit. Voltage Regulators and Stabilizers Regulators and stabilizers do the same thing. However, voltage regulators generally deal with output from DC power sources, whereas voltage stabilizers and conditioners typically maintain AC line voltage. See surge suppression and UPS.