Programmer for magnetic latching relays

Claim 1

A programmer for selectively controlling magnetic latching relays, which comprises: a first monostable multivibrator for receiving an activating signal; a second monostable multivibrator coupled to the output of said first monostable multivibrator; relay state-selector means for providing control signals to select the position of the relays; a first AND-driver device for generating an actuating voltage for each relay, said first AND-driver device having a first input coupled to a high-level signal, a second input coupled to the output of said first monostable multivibrator so that said first AND-driver device second input is energized with a high-level signal only during the occurrence of the quasi-stable state of said first monostable multivibrator, and an output coupled to the reset terminal of each relay coil; first output-driving means for providing a sustaining current for each relay, said first output-driving means having a control input coupled to the output of said second monostable multivibrator and having output terminals connected between the circuit ground and said reset terminal of each relay coil; a plurality of AND-driver devices for generating actuating voltages, one associated with each relay coil, each of said plurality of AND-driver devices having a frist input coupled to said relay state-selector means for receiving a control signal, a second input coupled to the output of said second monostable multivibrator so that the second input of each of said plurality of AND-driver devices is energized with a high-level signal only during the occurrence of the quasi-stable state of said second monostable multivibrator, and an output coupled to the set terminal of the associated relay coil; and a plurality of output-driving means for providing sustaining currents, one associated with each relay coil, each of said plurality of output-driving means having a control input coupled to the output of said first monostable multivibrator and having output terminals connected between the circuit ground and the set terminal of the associated relay coil, said first AND-driver device producing an actuating voltage establishing current through said relay coils in a first direction only during the occurrence of the quasi-stable state of said first monostable multivibrator, said plurality of output-driving devices being in a conducting state for supplying a sustaining current through said relay coils in said first direction only during the occurrence of the quasi-stable state of said first multivibrator, said plurality of AND-driver devices producing an actuating voltage establishing current through said associated relay coils in a second direction only upon the joint occurrence of said control signals from said relay state-selector means and of the quasi-stable state of said second monostable multivibrator, said first output-driving means being in a conducting state and supplying a sustaining curtent in said second direction only during the occurrence of the quasi-stable state of said second monostable multivibrator.