Found in a 90s Motorola documentation, this circuit makes it a PUT. This component is not very common today. The graph shows the performance of the circuit.
With this circuit it is possible to control a relay up to 100 mA with an extremely low input...
The circuit shown by figure 1 consists in a Schmitt-Trigger using two common general purpose NPN...
This oscillator, from an old Argentine publication from 1973, uses the inductance of the 500 ohms...