US 12,293,890 B2
Contact monitoring apparatus for a three-pole changeover contact
Christian Reinhold, Hameln (DE); and Peter Scholz, Brakel (DE)
Assigned to PHOENIX CONTACT GMBH & CO. KG, Blomberg (DE)
Appl. No. 18/559,570
Filed by Phoenix Contact GmbH & Co.KG, Blomberg (DE)
PCT Filed May 10, 2022, PCT No. PCT/EP2022/062552
§ 371(c)(1), (2) Date Nov. 8, 2023,
PCT Pub. No. WO2022/238361, PCT Pub. Date Nov. 17, 2022.
Claims priority of application No. 2021/5383 (BE), filed on May 12, 2021.
Prior Publication US 2024/0234060 A1, Jul. 11, 2024
Int. Cl. G01R 31/327 (2006.01); H01H 47/00 (2006.01)
CPC H01H 47/002 (2013.01) [G01R 31/3278 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A contact monitoring device for monitoring an electrical, three-pole changeover contact, comprising:
a signal generator, which is configured to generate a monitoring signal;
a coupling device, which is connected downstream from the signal generator;
a sensing circuit, which is connected downstream from the coupling device and which is coupled or can be coupled to the changeover contact,
wherein the sensing circuit comprises one or several impedances and is configured to provide, at the coupling device, a total impedance, which varies with a switch position of the changeover contact,
wherein the monitoring signal generation of the signal generator and thus the monitoring signal and/or a signal derived from the monitoring signal can be changed as a function of a switching position of the changeover contact by means of the sensing circuit, which is coupled to the signal generator via the coupling device;
an evaluation device, which is configured to detect the monitoring signal and/or the signal derived from the monitoring signal and/or a change of the monitoring signal and/or a change of the signal derived from the monitoring signal, in order to thus monitor the changeover contact,
wherein the sensing circuit is configured to change a resonance state of the signal generator, as a changed resonance state, for the monitoring signal and/or the signal derived from the monitoring signal in a different way for at least three different switch positions of the changeover contact.