Found in a 1967 General Electric documentation this circuit uses unijunction transistors that may be equivalent to those indicated. The number of stages can be modified.
The presented circuit is suggested by Texas Instruments (www.ti.com) in its Application Report...
This circuit with an industrial standard 4-20 mA interface uses a KPZ20G pressure sensor but can...
This circuit takes advantage of the inductance of the coil of a high-impedance phone to form the...