AVR series automatic AC voltage stabilizer is intelligent type micro -computer AC automatic production.It adopts the 8-bit CPU,and has functions of delay output,undervoltage indicator,overload protection, overvoltage protection.when mechine is overvoltage or undervoltage, LED of panel would indicate "Ho" or "Lo".when operate unnormally, LED would show "CHo" and flash.when operating normally,LED indicates output voltage value.