This high input impedance circuit was found in American documentation from the 1980s. The power supply must be symmetrical. The circuit applies to modern operational.
This circuit with an industrial standard 4-20 mA interface uses a KPZ20G pressure sensor but can...
This simple receiver with germanium transistor and listening on a crystal phone was discovered in a...
This circuit is from Motorola technical documentation from the 70s, but it can be easily assembled...