Patent GB-760450-A (GB)
Title: Improvements in or relating to supervisory arrangements for electric multi-stable state switching devices
Inventor: BAUMGART SIEGFRIED
IPC: B61L1/16
Filed: 1954-09-09
Abstract: 760,450. Axle counters. SIEMENS & HALSKE AKT.-GES. Sept. 9, 1954, No. 26201/54. Class 105. [Also in Group XIX] The correct operation of a step-by-step rotary switch is checked by connecting a contact bank of the switch in circuit with contacts controlled by a circuit element having two stable states and receiving the same impulses as the stepping switch, each impulse stepping'on the switch and changing the state of the circuit element. As described generally, Fig. 1, the circuit element comprises a polarized relay P, the windings 15, 16 of which are connected as shown to capacitors 12, 13 and the secondary of a transformer 14. Incoming impulses cause the closing of contact 703 connected to the primary of the transformer 14 and the arrangement is such that the contact 703 opens at the end of the first impulse the stepping switch 91 is actuated and the relay P changes its state to open contacts 151, 153 and close contacts 152, 154. When the contact 703 opens at the end of the second impulse the stepping switch 91 is again actuated and the relay P reverts to its initial state to close contacts 151, 153 and open contacts 152, 154. This sequence of. operations is repeated. The odd contacts of the stepping switch 91 are connected to the contact 153 and the even contacts to the contact 154. If the stepping switch actuates and the relay P changes its state at the end of incoming impulses a circuit is permanently established to relay U. Failure of the stepping switch 91 or relay P results in de-energization of relay U. The invention is illustrated in Fig. 2 as applied to an axle counting arrangement. Incoming axles effect actuation of stepping switch EZ and outgoing axles effect actuation of a stepping switch AZ. In this case the circuit element having two stable states comprises a relay K having two windings 20, 21 connected as shown to the contacts of the bank EZ1b of the switch EZ. Associated with the relay K is a relay L the windings 30, 31 of which are so connected to the contacts of the bank EZ1b and contacts of the relay K that the relay K is made to change its state each time the wiper EZ1b moves from contact n to contact 1. When the wiper first moves from contact n to contact 1 relay K is energized closing contact 201 so that relay L is energized when the wiper moves from contact 1 to contact 2. When the wiper next passes from contact n to contact 1 relay K is de-energized opening contact 201 so that relay L is deenergized when the wiper moves from contact 1 to contact 2. This sequence of operations is repeated. A second order contact bank EZ2b of the switch EZ has its contacts connected as shown to contacts 202, 203 of the relay K. This bank EZ2b also receives impulses every time the wiper EZ1b passes from contact n to contact 1. If the stopping switch EZ2b actuates and the relay'K changes its state upon reception of an impulse a supervisory circuit is closed through contact 202 or 203 and one or'other of testing relays H, Y. The circuit arrangements of the relays H, Y ensure that these relays are operated alternately, relay Y when the " counting-in " stepping switch and the " counting- out " stepping switch are not coincident and relay H when they are. Failure of the relays H or Y to operate alternately indicates incorrect operation of the circuit. The relays H, Y control contacts 804, 504 in the circuit of relay G, energization of which indicates that the track section is clear. The arrangement may be used to check the operation of a chain of relays.