PURPOSE: To provide a voltage adjuster provided with plural output stages isolated from a single voltage source, which applies the plural commonly operated voltage sources.

CONSTITUTION: An automobile voltage adjuster 32 which applies plural adjusted outputs using a transient state protection isolated output stages(TPIOS) for preventing a system failure condition under which any one output has an adverse influence on the other output is provided. In an automobile circumstance using a nominal 14V power source, each output can be present in a range from -4V to +26V without generating any damage or without having any adverse influence on the output without any failure. This circuit uses a relatively compact NPN output path transistor. Thus, it is necessary only to provide a by-pass capacitor 26-28 for stabilization with a relatively low cost.