Fault detector for igniter testing using high frequency noise

Claim 2

Apparatus for testing an electrical resistance type igniter for operational defects, comprising: means for applying an operating voltage to the igniter to cause the generation of high frequency noise by the igniter if it is defective; an inductive impedance connected to the igniter for sampling signals developed by the igniter; filter means connected to said inductive impedance for passing high frequency noise; amplifying means connected to said filter means for amplifying the signal received therefrom; signal level detector means connected to said amplifying means for desensitizing the circuit with respect to noise signals below a reference level; and signal means connected to said level detector means and operative to indicate a defective igniter.

Claim 3

Apparatus according to claim 1, wherein said inductive impedance comprises an inductor connected in series with said igniter.

Claim 4

Apparatus according to claim 1, wherein said inductive impedance comprises a radio frequency transformer including a primary winding connected to the igniter and a secondary winding connected to said filter means. 4. Apparatus for testing electrical resistance type igniters for operational defects comprising: means for connecting an igniter to an electrical supply for providing an operational voltage to the igniter, a defective igniter being responsive to the operational voltage to generate high frequency noise; a radio frequency transformer for sampling signals developed across the igniter, said transformer including a primary winding connected to the igniter and a secondary winding; a high pass filter connected to said secondary winding for passing hIgh frequency noise; an amplifier connected to said high pass filter to amplify signals passed thereby; a comparator circuit including a first input connected to said amplifier, a second input, and a reference level circuit connected to said second input, said comparator circuit being operable to provide first and second signals when the signal level at said first input is above and below, respectively, the reference levels; an inverter connected to said comparator circuit to invert the first and second signals; first and second indicating means including first and second drivers and first and second lamps connected to respective drivers for identifying defective and sound igniters, respectively; a latching circuit including a first input and first and second outputs, said first input connected to said inverter, said first and second outputs connected to said first and second drivers, respectively, said latching circuit being responsive to the inverted first and second signals to operate said first and second drivers, respectively.

Claim 5

Apparatus for testing electrical resistance type igniters for operational defects, comprising: means for connecting an igniter to an electrical supply for providing an operational voltage to the igniter, a defective igniter being responsive to the operational voltage to generate high frequency noise; an inductor connected in series with the igniter to sample signals developed across the igniter; a high pass filter connected to said inductor for passing high frequency noise; an amplifier connected to said high pass filter to amplify signals passed thereby; a comparator circuit including a first input connected to said amplifier, a second input, and a reference level circuit connected to said second input, said comparator circuit being operable to provide first and second signals when the signal level at said first input is above and below, respectively, the reference level; an inverter connected to said comparator circuit to invert the first and second signals; first and second indicating means including first and second drivers and first and second lamps connected to respective drivers for identifying defective and sound igniters, respectively; a latching circuit including a first input and first and second outputs, said first input connected to said inverter, said first and second outputs connected to said first and second drivers, respectively, said latching circuit responsive to the inverted first and second signals to operate said first and second drivers, respectively.

Claim 6

Apparatus for testing electrical resistance type igniters for operational defects, comprising: means for connecting an igniter to an electrical supply for providing an operational voltage to the igniter, a defective igniter being responsive to the operational voltage to generate high frequency noise; an inductor connected in series with the igniter to sample signals developed across the igniter; a high pass filter connected to said inductor for passing high frequency noise; an amplifier connected to said high pass filter to amplify signals passed thereby; a comparator circuit including a first input connected to said amplifier, a second input, and a reference level circuit connected to said second input, said comparator circuit being operable to provide first and second signals when the signal level at said first input is above and below, respectively, the reference level; an inverter connected to said comparator circuit to invert the first and second signals; first and second indicating means including first and second drivers and first and second lamps connected to respective drivers for identifying defective and sound igniters, respectively; a latching circuit including a first input and first and second outputs, said first input connected to said inverter, said first and second outputs connected to said first and second drivers, respectively, said latching circuit responsive to the inverted first and second signals to operate said first and second drivers, respectively.

Claim 7

In an apparatus for testing electrical resistance type igniters wherein an operating voltage is applied to an igniter to effect the generation of high frequency noise by a defective igniter, an impedance is connected in circuit with the igniter to sample signals developed by the igniter, and a signal level detection circuit is connected to the impedance for determining whether the sampled signals represent a defective igniter or a sound igniter, the improvement comprising: means for increasing the signal level of the sampled signals, wherein the impedance is an inductor connected in series with the igniter.

Claim 8

In an apparatus for testing electrical resistance type igniters wherein an operating voltage is applied to an igniter to effect the generation of high frequency noise by a defective igniter, an impedance is connected in circuit with the igniter to sample signals developed by the igniter, and a signal level detection circuit is connected to the impedance for determining whether the sampled signals represent a defective igniter or a sound igniter, the improvement comprising: means for increasing the signal level of the sampled signals, wherein the impedance is an inductor connected in series with the igniter.

Claim 9

In an apparatus for testing electrical resistance type igniters wherein an operating voltage is applied to an igniter to effect the generation of high frequency noise by a defective igniter, an impedance is connected in circuit with the igniter to sample signals developed by the igniter, and a signal level detection circuit is connected to the impedance for determining whether the sampled signals represent a defective igniter or a sound igniter, the improvement comprising: means for increasing the signal level of the sampled signals, wherein the impedance is a radio frequency transformer including a primary winding connected in series with the igniter and a secondary winding connected to the signal level detection circuit.

Claim 10

In an apparatus for testing electrical resistance type igniters wherein an operating voltage is applied to an igniter to effect the generation of high frequency noise by a defective igniter, an impedance is connected in circuit with the igniter to sample signals developed by the igniter, and a signal level detection circuit is connected to the impedance for determining whether the sampled signals represent a defective igniter or a sound igniter, the improvement comprising: means for increasing the signal level of the sampled signals, wherein the impedance is a radio frequency transformer including a primary winding connected in series with the igniter and a secondary winding connected to the signal level detection circuit.

Claim 11

Apparatus for testing for a faulty condItion of an electrical resistance type igniter, comprising: means for providing power to an igniter under test to cause the generation of high frequency noise from a faulty igniter, detecting means connected to the igniter under test for detecting the presence of high frequency noise generated by a faulty igniter, said detecting means including an inductor for sampling the high frequency noise, and signal means responsive to the detecting means for indicating a faulty condition of the igniter under test.

Claim 12

Apparatus for testing for a faulty condItion of an electrical resistance type igniter, comprising: means for providing power to an igniter under test to cause the generation of high frequency noise from a faulty igniter, detecting means connected to the igniter under test for detecting the presence of high frequency noise generated by a faulty igniter, said detecting means including an inductor for sampling the high frequency noise, and signal means responsive to the detecting means for indicating a faulty condition of the igniter under test.

Claim 13

Apparatus for testing for a faulty condition of an electrical resistance type igniter, comprising: means for providing power to an igniter under test to cause the generation of high frequency noise from a faulty igniter, detecting means responsive to the igniter under test for detecting the presence of high frequency noise generated by a faulty igniter, said detecting means including a high frequency transformer for sampling the high frequency noise, and signal means responsive to the detecting means for indicating a faulty condition of the igniter under test.

Claim 14

Apparatus for testing for a faulty condition of an electrical resistance type igniter, comprising: means for providing power to an igniter under test to cause the generation of high frequency noise from a faulty igniter, detecting means responsive to the igniter under test for detecting the presence of high frequency noise generated by a faulty igniter, said detecting means including a high frequency transformer for sampling the high frequency noise, and signal means responsive to the detecting means for indicating a faulty condition of the igniter under test.

Claim 15

Apparatus for testing for a faulty condition of an electrical resistance type igniter, said apparatus comprising: means for providing power to an igniter under test to cause the generation of high frequency noise from a faulty igniter; detecting means responsive to the igniter under test for detecting the presence of high frequency noise, said detecting means including filter means for passing only high frequency noise, a high frequency transformer for coupling the high frequency noise to said filter means, amplification means electrically connected to the filter means for amplifying the high frequency noise passed by the filter means, and comparator means electrically connected to the amplification means for providing a reference signal level, comparing the level of the amplified high frequency noise with the reference signal level, and passing only amplified high frequency noise above the reference level; and signal means responsive to the detecting means for indicating a faulty condition of the igniter under test, said signal means comprising switch means including a memory circuit electrically connected to the comparator means and responsive to the comparator means, and indicator means responsive to the switch means for demonstrating a faulty condition of the igniter under test.

Claim 16

Apparatus for testing for a faulty condition of an electrical resistance type igniter, said apparatus comprising: means for providing power to an igniter under test to cause the generation of high frequency noise from a faulty igniter; detecting means responsive to the igniter under test for detecting the presence of high frequency noise, said detecting means including filter means for passing only high frequency noise, a high frequency transformer for coupling the high frequency noise to said filter means, amplification means electrically connected to the filter means for amplifying the high frequency noise passed by the filter means, and comparator means electrically connected to the amplification means for providing a reference signal level, comparing the level of the amplified high frequency noise with the reference signal level, and passing only amplified high frequency noise above the reference level; and signal means responsive to the detecting means for indicating a faulty condition of the igniter under test, said signal means comprising switch means including a memory circuit electrically connected to the comparator means and responsive to the comparator means, and indicator means responsive to the switch means for demonstrating a faulty condition of the igniter under test.