Found in Ferranti's 1969 documentation, this circuit can be mounted with a modern equivalent transistor. The circuit has a 4 V immunity and can be used as a shield for sensors.
This circuit from a 1967 documentation generates 2.5 Hz signals depending on the capacitors used,...
This circuit uses a sensitive vibrator that can be made with a reed-switch to activate a relay from...
This circuit is from an old Mullard (Philips) manual with applications using the 555. Choosing...