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.
Found in National Semiconductor documentation from the 1980s, this circuit uses an operational...
This basic voltmeter circuit has an input resistance of 2 M. The instrument is 100 uA and the...
This simple alarm using only transistors was found in a 1990 publication. It can be powered by D...