摘要:
A vertical amplifier apparatus with a beam-finding function for an oscilloscope including an analog multiplier and a gain control circuit. The analog multiplier multiplies an input signal to the vertical amplifier by a gain control signal. The gain control circuit outputs a DC voltage as the gain control signal. In a beam-finding mode, the gain control circuit supplies the analog multiplier with the gain control signal whose absolute value is much smaller than that of the gain control signal in a normal mode. This makes is possible to obviate a dedicated beam-finder circuit. In a multi-channel oscilloscope, the beam-finding operation can be performed independently for each channel.