This circuit is from the 1983 Intersil Databook. The display is plasma and must be excited by a high voltage circuit. The components used in this configuration are not common today.
This circuit is from 1977 documentation, but can be assembled with BC548 for Q1, Q2 and Q4, BC558...
Found in American documentation from the 90s, this circuit uses components that are still common...
This high impedance input amplifier is suitable for the use with piezoelectric sources such as...