High impedance preamplifier stage (CB4683E)

In the figure we have a high input impedance stage with a general purpose PNP transistor. An NPN transistor by reversing power polarity can be used.

Neon oscillator (CB4239E)
This simple neon lamp oscillator produces a 140 Hz, 40 V peak-to-peak signal. The frequency is given...
KE1xF 168 MHz ARM Microcontrollers (COM129E)
November 2016 - NXP ARM Cortex microcontrollers for serial interfacing applications, NXP 32-bit...
Capacitance Switch (CB4993E)
Although indicated in the original publication of the 1980s as a capacitance switch, the circuit...