This series relay single-phase voltage stabilizers, adopting the double sampling, double stabilizing voltage, and the advanced electronic automatic controller, which employs the time-base IC for time-delay, offer the advantages of quick work, accurate timing, steady performance, safety and electricity-saving, excellent design, reasonable construction, easy operation, wide input voltage range, etc. The voltage stabilizer are the universal protectors in the highgrade household appliances, such as refrigerator, telivision, and so on.