SSR based phase angle controller with analog control to adjust power on resistive loads (linear power law response) Overvoltage protection by varistor - Main frequency range : 40 to 70Hz with self adaptation - 8-30V supply voltage and Green LED visualization on the input - 0-5V analog input voltage - IP20 protection by flaps on terminals - Two removable input spring connectors - Grey: Supply Orange : Analog input 0-5V