Test contact connection checking method and circuit
First Claim
1. A method of checking a contact impedance, comprising the steps of:
- providing a device under test having a contact point connected to a source lead and a sense lead, said contact impedance being the impedance from the source lead through the contact point to the sense lead;
applying a pulse to the contact impedance to create a check pulse; and
comparing the check pulse with a threshold to produce a signal indicative of a contact fault.
1 Assignment
0 Petitions
Accused Products
Abstract
A contact resistance check circuit and method for verifying that a sufficient electrical connection is established between a source and a sense lead of a Kelvin connection. The circuit includes a microprocessor for driving a transformer that is connected to the source/sense probe (i.e., contact resistance) with an input pulse. The input pulse is altered in relation to the magnitude of the contact resistance to produce a check pulse. A comparator is used to compare the check pulse with a threshold voltage and for generating a fault indication signal. A flip flop then stores the fault indication signal so that the fault indication signal may be monitored by the microprocessor.
-
Citations
8 Claims
-
1. A method of checking a contact impedance, comprising the steps of:
-
providing a device under test having a contact point connected to a source lead and a sense lead, said contact impedance being the impedance from the source lead through the contact point to the sense lead; applying a pulse to the contact impedance to create a check pulse; and comparing the check pulse with a threshold to produce a signal indicative of a contact fault.
-
-
2. A method for checking a contact resistance, comprising the steps of:
-
generating a pulse by a microprocessor; driving a transformer connected to the contact resistance with said pulse so as to create a check pulse, generating a threshold voltage with a voltage divider; comparing the check pulse and the threshold voltage to generate a contact fault indication signal; storing the fault indication signal; and monitoring the stored signal by the microprocessor. - View Dependent Claims (3, 4)
-
-
5. A contact resistance check circuit, comprising:
-
a microprocessor for generating a pulse; a transformer having a primary winding connected to be driven by said pulse and a secondary winding connected to the contact resistance, said transformer/contact resistance connection altering said pulse in relation to the magnitude of the contact resistance so as to create a check pulse; a comparator connected to compare the check pulse and a threshold voltage generated by a voltage divider, said comparator generating a contact fault indication signal; and a flip flop connected to store the fault indication signal for monitoring by the microprocessor. - View Dependent Claims (6)
-
-
7. A contact resistance check circuit, comprising:
-
a microprocessor for generating a pulse; an inverter connected to the microprocessor for inverting said pulse; a transformer having a primary winding connected to be driven by the inverted said pulse and a secondary winding connected to the contact resistance, said transformer/contact resistance connection having the effect of altering the inverted said pulse in relation to the magnitude of the contact resistance so as to create a check pulse; a comparator connected to compare the check pulse and a threshold voltage generated by a voltage divider, said comparator generating a contact fault indication signal; a second inverter for inverting the fault indication signal; and a flip flop connected to the second inverter and for storing the inverted fault indication signal for monitoring by the microprocessor. - View Dependent Claims (8)
-
Specification