This simple timer with unijunction transistor was found in an old American technical documentation. We can use 2N2646 for the unijunction and BC548 for the transistor.
The sensors in this circuit, found in a 1999 documentation, are stripped wire tips at different levels...
This traditional crystal oscillator configuration can use any CMOS gate configured as an inverter. R1...
This amplification stage circuit with a germanium transistor was found in a 1980s documentation. The...