This circuit is from a documentation on the MC1539 from Motorola and may, however, be implemented with equivalent operations. The transistor also supports equivalent.
This circuit locks when the sensors are opened. The relay can be 6 or 12 V depending on the power...
This is a conventional differentiator configuration with operational amplifier. In principle any...
This circuit should be used with low frequency signals only. The circuit is from a documentation from the...