AC or DC voltage (pulsating or filtered) can be connected to the input terminals. Due to the high operating frequency of the inverter, some highly sensitive radio or microprocessor devices may malfunction. It is recommended to install an additional filter (consisting of a current-compensated choke with an inductance of 2× 5÷15mH and a capacitor C= 0.33÷1µF) between the power supply and the receiver. When the load is increased above Imax, the power supply will stabilize the current and the output voltage will decrease. When the output terminals are shorted, the power supply operates at a frequency of approx. 1.5 kHz, which is manifested by a clear squeak.