Power switching circuit

Claim 2

A power switching circuit comprising (a) a base plate carrying a first annular slip ring having a gap forming a break in continuity, (b) an isolated contact on the base plate within the gap at the same radius as the ring, (c) a second continuous slip ring concentric with the contact ring, (d) a contact arm driven by a motor connecting the second ring to the contact ring, (e) means connecting the first ring and the second ring in series with a motor across a source of a.c. current, whereby current can be fed to the motor until the contact arm reaches the gap, (f) a third continuous annular slip ring concentric with the first and second rings, (g) a multiplicity of contacts in a ring at equal radii from the centre of the first and second rings, (h) means connecting the third slip ring and each of the contacts in sequence as the motor rotates, whereby external circuits connected individually to each of the contacts are energized once as the motor rotates, the motor stopping when the contact arm reaches said gap.

Claim 3

A power switching circuit as defined in claim 1, further including circuit means for applying a pulse of current to start the motor, connected to said isolated contact.

Claim 4

A power switching circuit as defined in claim 2 in which the circuit means is comprised of (i) a momentary make switch in series with an RS1 relay connected across the source of current, (ii) a make contact of the RS1 relay connected in series with the motor, (iii) an RC1 relay connected across the source of current, (iv) a make contact of the RC1 relay and a make contact of the RS1 relay connected in parallel with each other, in series with the RC1 relay; a break contact of the RC1 relay being connected in series with the RS1 relay, (v) an FC1 relay connected to one of contacts in said ring, and in series with the third slip ring across the source of current and a second make contact of the RC1 relay, a break contact of the FC relay being connected in series with the FC1 relay, whereby upon closing of the momentary switch, the RS1 relay is caused to operate, allowing current to flow via first the isolated contact and then the first slip ring to the motor, and also causing operation of the RC1 relay and lockup through its make contact in parallel with the RS1 contact; closure of the RC1 relay causing its break contact to open the circuit with subsequent release of the RS1 relay and closure of part of the circuit to the FC1 relay whereupon rotation of the contact arm to said one of the contacts in said ring causes operation of the FC1 relay resulting in release of the FC1 and RC1 relays.

Claim 5

A power switching circuit as defined in claim 3 further including power switching relays connected to additional ones of the contacts in said ring for momentary operation thereof, and to the source of current in common, a break contact of said FC relay being connected in series with the RC1 relay.

Claim 6

A power switching circuit as defined in claim 3 or 4, further including a diode connected in series with the RS1 relay, and an RS2 relay having a diode in series therewith connected in parallel with the RS1 relay and series diode, both latter diodes being connected in opposite polarity sense; a further diode connected in series with the FC1 relay, an FC2 relay having a diode connected in series therewith connected in parallel with the FC1 relay and series diodes, both latter diodes being connected in opposite polarity sense; an RC2 relay connected in series with an RC2 and an RS2 make contact, in parallel with the RC1 relay and RS1 contact series combination, an FC2 relay break contact being connected in series with the FC1 relay break contact; a diode connected in series with the RC1 make contact in the FC relay circuit, in the same polarity sense as the diode in series with the RS1 relay; a further diode in series with an RC2 make contact, which are connected in parallel with the RC1 make contact and diode in the FC relay circuit, the latter two diodes being in the opposite polarity sense; a diode in series with the momentary switch, and a second momentary switch in series with a further diode, which are connected in parallel with the first manual switch and associated diode, the latter diode being connected in the opposite polarity sense, the polarities of the diodes being such that upon closure of one of the momentary contact switches, the RS1, RC1 power switching the FC1 relays are caused to operate with the rotation of the motor, and upon alternative closure of the other of the momentary contact switches, the RS2, RC2 and FC2 relays are caused to operate with further rotations of the motor.

Claim 7

A power switching circuit as defined in claim 5, further including a control make contact on each power switching relay, one terminal of each control contact being connected together, the other of each control contact being connected together at a junction through a pair of diodes, the opposite poles of each latter diode being connected together, said one terminals and said junction being connected in a series circuit with a magnetic latching relay and a source of current, the latching relay comprising a single pole double throw switch, the moving contact of the switch being connected in said series circuit, the non-moving contacts being connected together to a second junction through a pair of diodes having opposite poles connected to the second junction, the second junction being connected to the latching relay in said series circuit, and further including a pair of power switching contacts on the latching relay for connection to an external circuit.