This circuit is from a publication from the 70s. The operational amplifier is from the period. Modern equivalents according to the motor current must be used.
The time the output is high (1) of a TLCSSB in the astable configuration depends on Ra and C. The...
The adjustment of the maximum load voltage is made in the trimpot. The circuit is from 1994...
This circuit from a 1967 documentation generates 2.5 Hz signals depending on the capacitors used,...