The transistors of this circuit found in a 1965 magazine can be the BC558 and the sensitive 12 V x 50 mA relay. The other components are common.
This unity gain circuit was found in the February 1995 Electronics Now magazine. The frequency is 10 kHz,...
Found in a 1967 Electronic Design, this transistorized circuit compresses and then expands a pulse....
This TTL pulse stretcher or stretcher was found in a 90's EDN. The time constant R x C1 determines...