This is a voltage safety protector, good for an automatic protection of the home appliances in case of under-voltage, ultra-voltage and electricity stoppage. For instance, it may be always harmful to the normal operation, cut their service life, or even burn down the compressor motors for air-conditioners, refrigerators and freezing cabinets if the supply voltage is too low or too high. Especially, instant power stoppage and restarting supply with the electricity net creates a strong voltage impact which is very hazardous and may damage the compressors. This protector applies a digifax technique, which can immediately disconnect the load supply and provide the compressor with a time-retardant power reconnection with a perfect result of protection for the compressor.