This circuit of the 70's uses transistors of the time. The circuit can amplify signals from 10 Hz to 100 kHz and modern equivalent components can be used. The circuit is from Ferranti.
Figure bellow shows a ring oscillator using five inverters of a 4049. [The circuit operates only...
This circuit, which can also be used with flashing LEDs as long as they have in parallel a charge...
June 2017 - The new TE Connectivity FSJMI series of illuminated tactiles switches is now available in Mouser...