Relay tester

Claim 3

The method of claim 1 wherein said pulse pattern is sequentially applied to said latch coil and said reset coil, one after the other.

Claim 4

The method of claim 1 wherein said relay includes a plurality of movable contacts, each shiftable between first and second positions as said relay is operated between said latching and reset states thereof, and wherein said step of monitoring the state of the relay comprises monitoring of a plurality of electrical circuits each connected respectively with an individual one of said movable contacts, whereby the positions of a plurality of said movable contacts are monitored upon application of each of said pulses to each of said coils.

Claim 5

The method of claim 1 wherein said relay includes an armature movable between first and second positions in response to energization of said latch and reset coils respectively, and including a magnetic circuit for exerting a magnetic holding force to retain the armature in either of said first and second positions, said pattern of pulses including a test pulse having a magnitude not greater than a magnitude sufficient to cause the coil energized thereby to exert a magnetic force that is considerably less than said magnetic holding force, said pattern of pulses further including a driving pulse having a magnitude sufficient to cause the coil energized thereby to exert a magnetic force on the armature sufficient to overcome the magnetic holding force.

Claim 6

The method of claim 4 wherein said relay includes a first pair of fixed contacts and a first movable contact cooperating therewith, a second pair of fixed contacts and a second movable contact cooperating therewith, and wherein said monitoring of the state of said relay comprises connecting said movable contacts to each other, connecting each of said fixed contacts to a voltage divider circuit, connecting an electrical circuit between said common connection of said movable contacts and one fixed contact of said first and second pairs of fixed contacts, and monitoring said electrical circuit.

Claim 7

Apparatus for testing a relay of the type having an armature movable to operate a movable contact between a first position in engagement with a fixed contact and a second position, a relay coil for driving the armature to move the movable contact between said first and second positions, and means for exerting a holding force for holding the armature and movable contact in one of said first and second positions in the absence of energization of said coil, said testing apparatus comprising a monitoring circuit, means for connecting said monitoring circuit to said fixed and movable contacts, means for energizing said coil with a pattern of pulses, a larger one of said pulses having a magnitude sufficient to cause the coil to exert a force great enough to overcome said holding force whereby the movable contact is moved from one of said positions to the other, said pattern of pulses including a smaller pulse having a considerably smaller magnitude that causes the coil to exert a magnetic force considerably less than said holding force, whereby said movable contact will be driven from one of said positions to the other upon application of said smaller magnitude pulse only if the relay is defective, means for obtaining a signal from said monitoring circuit representing the position of said movable contact, and means for comparing said signal with occurrence of each of said larger and smaller pulses of said pattern.

Claim 8

Apparatus for testing a relay of the type having an armature movable to operate a movable contact between a first position in engagement with a fixed contact and a second position, a relay coil for driving the armature to move the movable contact between said first and second positions, and means for exerting a holding force for holding the armature and movable contact in one of said first and second positions in the absence of energization of said coil, said testing apparatus comprising a monitoring circuit, means for connecting said monitoring circuit to said fixed and movable contacts, means for energizing said coil with a pattern of pulses, a larger one of said pulses having a magnitude sufficient to cause the coil to exert a force great enough to overcome said holding force whereby the movable contact is moved from one of said positions to the other, said pattern of pulses including a smaller pulse having a considerably smaller magnitude that causes the coil to exert a magnetic force considerably less than said holding force, whereby said movable contact will be driven from one of said positions to the other upon application of said smaller magnitude pulse only if the relay is defective, means for obtaining a signal from said monitoring circuit representing the position of said movable contact, and means for comparing said signal with occurrence of each of said larger and smaller pulses of said pattern.

Claim 9

The testing apparatus of claim 6 wherein said relay is of the type having a latch coil and a reset coil, first and second movable contacts respectively movable between the contacts of first and second pairs of fixed contacts, said apparatus including means for connecting said movable contacts to a common point in said monitoring circuit, said monitoring circuit including means connected with one contact of each oF said first and second pairs of fixed contacts for generating a first pair of relay state signals and further including means connected with a second contact of each of said first and second fixed contacts for generating a second pair of relay state signals, said means for energizing said coil with a pattern of pulses comprising means for generating first and second pairs of pulses, each said pair of pulses comprising one of said smaller pulses and one of said larger pulses, means for applying said first and second pairs of pulses to said latch and reset coils in sequence, and a plurality of comparison means, each said comparison means being individually responsive to one of the pulses of said first and second pairs of pulses and to respective pairs of said relay state signals for providing an output indicative of the quality of the relay upon occurrence of each of the pulses of said pattern of pulses.

Claim 10

For use with a two coil latching relay of the type having first and second pairs of fixed contacts, first and second movable contacts, an armature movable between latch and reset positions for moving said first and second movable contacts between positions in contact with different ones of said fixed contacts, a latch coil for driving the armature to a latch position and a reset coil for driving the armature to a reset position, and a magnetic circuit for exerting a holding force for holding the armature in either said latch position or said reset position when the coils are de-energized, testing apparatus comprising means for generating a pattern of successive pulses of which one pulse has a magnitude considerably less than the magnitude required to energize one of said coils to overcome said holding force, and a following pulse of said pattern having a magnitude sufficient to energize one of said coils to overcome the holding force and switch the armature from one of said positions to the other, means for applying said pattern sequentially to said latch and reset coils respectively, and means for monitoring the state of said relay upon occurrence of each of the pulses of a group of pulses of said pattern.

Claim 11

For use with a two coil latching relay of the type having first and second pairs of fixed contacts, first and second movable contacts, an armature movable between latch and reset positions for moving said first and second movable contacts between positions in contact with different ones of said fixed contacts, a latch coil for driving the armature to a latch position and a reset coil for driving the armature to a reset position, and a magnetic circuit for exerting a holding force for holding the armature in either said latch position or said reset position when the coils are de-energized, testing apparatus comprising means for generating a pattern of successive pulses of which one pulse has a magnitude considerably less than the magnitude required to energize one of said coils to overcome said holding force, and a following pulse of said pattern having a magnitude sufficient to energize one of said coils to overcome the holding force and switch the armature from one of said positions to the other, means for applying said pattern sequentially to said latch and reset coils respectively, and means for monitoring the state of said relay upon occurrence of each of the pulses of a group of pulses of said pattern.

Claim 12

The apparatus of claim 8 wherein said pulse pattern comprises first and second sequential pairs of sequential pulses, each pair of pulses comprising a relatively small test pulse followed by a relatively large switching pulse, said first pair of pulses being applied to one of said coils and said second pair of pulses being applied to the other of said coils, whereby each of said coils is first tested by a low magnitude test pulse and then tested by a relatively large magnitude switching pulse.

Claim 13

For use with a two coil latching relay of the type having first and second pairs of fixed contacts, first and second movable contacts, an armature movable between latch and reset positions for moving said first and second movable contacts between positions in contact with different ones of said fixed contacts, a latch coil for driving the armature to a latch position and a reset coil for driving the armature to a reset position, and a magnetic circuit for exerting a holding force for holding the armature in either said latch position or said reset position when the coils are de-energized, testing apparatus comprising means for generating a pattern of successive pulses of which one pulse has a magnitude considerably less than the magnitude required to energize one of said coils to overcome said holding force, and a following pulse of said pattern having a magnitude sufficient to energize one of said coils to overcome the holding and switch the armature from said one of said force positions to the other, means for applying said pattern sequentially to said latch and reset coils respectively, and means for monitoring the state of said relay upon occurrence of each of the pulses of a group of pulses of said pattern, said pulse pattern comprising first and second sequential pairs of sequential pulses, each pair of pulses comprising a relatively small test pUlse followed by a relatively large switching pulse, said first pair of pulses being applied to one of said coils and said second pair of pulses being applied to the other of said coils, whereby each of said coils is first tested by a low magnitude test pulse and then tested by a relatively large magnitude switching pulse, said means for monitoring including a monitoring circuit for deriving a plurality of relay state signals from each of said fixed contacts respectively and including means connected to both of said movable contacts, a plurality of logic comparison circuits each having an input from a respective one of the pulses of the pairs of pulses and also having second and third inputs from a first one of the contacts of the first pair of fixed contacts and from a first one of the contacts of the second pair of fixed contacts, whereby the quality of the relay is monitored upon the application of each test switching pulse to each of said latch and reset coils.

Claim 14

For use with a two coil latching relay of the type having first and second pairs of fixed contacts, first and second movable contacts, an armature movable between latch and reset positions for moving said first and second movable contacts between positions in contact with different ones of said fixed contacts, a latch coil for driving the armature to a latch position and a reset coil for driving the armature to a reset position, and a magnetic circuit for exerting a holding force for holding the armature in either said latch position or said reset position when the coils are de-energized, testing apparatus comprising means for generating a pattern of successive pulses of which one pulse has a magnitude considerably less than the magnitude required to energize one of said coils to overcome said holding force, and a following pulse of said pattern having a magnitude sufficient to energize one of said coils to overcome the holding and switch the armature from said one of said force positions to the other, means for applying said pattern sequentially to said latch and reset coils respectively, and means for monitoring the state of said relay upon occurrence of each of the pulses of a group of pulses of said pattern, said pulse pattern comprising first and second sequential pairs of sequential pulses, each pair of pulses comprising a relatively small test pUlse followed by a relatively large switching pulse, said first pair of pulses being applied to one of said coils and said second pair of pulses being applied to the other of said coils, whereby each of said coils is first tested by a low magnitude test pulse and then tested by a relatively large magnitude switching pulse, said means for monitoring including a monitoring circuit for deriving a plurality of relay state signals from each of said fixed contacts respectively and including means connected to both of said movable contacts, a plurality of logic comparison circuits each having an input from a respective one of the pulses of the pairs of pulses and also having second and third inputs from a first one of the contacts of the first pair of fixed contacts and from a first one of the contacts of the second pair of fixed contacts, whereby the quality of the relay is monitored upon the application of each test switching pulse to each of said latch and reset coils.

Claim 15

The apparatus of claim 10 wherein said means for generating said pattern of pulses comprises a pulse generator, a pulse counter responsive to said pulse generator for providing a plurality of sequential outputs, a cycle counter responsive to said pulse counter and providing a disable output to said pulse generator upon completion of a number of counts thereof, a plurality of pulse shaping circuits each responsive to a respective one of the outputs of said pulse counter, a plurality of voltage sources each providing an input to a respective one of said pulse shaping circuits, means for connecting a first pair of said pulse shaping circuits to said latch coil, and means for connecting a second pair of said pulse shaping circuits to said reset coil.

Claim 16

The apparatus of claim 10 wherein said monitoring circuit includes a first voltage divider having an intermediate point thereof connected to one contact of said first pair of fixed contacts, a second voltage divider having an intermediate point thereof connected to the other contact of said first pair of said fixed contacts, a third voltage divider having an intermediate point thereof connected to a first contact of said second pair of fixed contacts, a fourth voltage divider having an intermediate point thereof connected to the other contact of said second pair of said fixed contacts, means connecting said first and second movable contacts in common with one side of all of said voltage dividers, said logic comparison circuits comprising a first comparator having a first input from a first pulse of said pattern, and having second and third inputs from the intermediate points of two of said voltage dividers, a second comparator having a first input from a second one of the pulses of said pattern and having second and third inputs from the intermediate points of two of said voltage dividers, a third comparator having a first input from a third pulse of said pattern and having second and third inputs from the intermediate points of two of said voltage dividers, and a fourth comparator having a first input from a fourth pulse of said pattern and having second and third inputs from the intermediate points of two of said voltage dividers, a plurality of flip-flops each having an input from a respective one of said comparators, a plurality of relay quality display devices respectively connected to different ones of said flip-flops, a coincidence gate having inputs from each of said flip-flops and having an output, and a display device having an input from said coincidence circuit for indicating successful tests of said relay.