Found in a 1980s American documentation, this circuit appears with variations elsewhere in this section. The circuit activates a relay according to the supply voltage.
This circuit is from 1997 documentation. It uses CMOS circuits to produce the effects, being...
This circuit is from a 1979 documentation. The critical component is the CA3130 operational...
This circuit was obtained in a Motorola documentation from 1968. The circuit uses a power...