Integrated capacitive discharge electrical bonding assurance system

Abstract

In one embodiment, an aircraft electronics system includes a hardware processor, a charge collection circuit to collect charge; a switching circuit controlled by the hardware processor to discharge the charge collected on the charge collection circuit through a bonding circuit formed from a chassis and a bonding surface; and a voltage measurement circuit to measure a voltage difference between measurement terminals across the chassis and the bonding surface.

1 - 20 . (canceled) 
     
     
         21 . An aircraft electronics system comprising:
 a charge collection circuit for collecting charge;   a switching circuit for discharging the collected charge through a bonding circuit formed between a chassis and a bonding surface; and   a voltage measurement circuit for measuring a voltage difference between measurement terminals across the chassis and the bonding surface;   wherein the switching circuit comprises a first transistor disposed between the charge collection circuit and the voltage measurement circuit and a second transistor disposed between the field effect transistor and ground.   
     
     
         22 . The aircraft electronics system of  claim 21 , wherein the first transistor comprises a field effect transistor (“FET”). 
     
     
         23 . The aircraft electronics system of  claim 22 , wherein the FET comprises a p channel FET. 
     
     
         24 . The aircraft electronics system of  claim 21 , wherein the second transistor comprises a bipolar junction transistor (“BJT”). 
     
     
         25 . The aircraft electronics system of  claim 21 , wherein the charge collection circuit comprises one or more capacitors coupled to a voltage source. 
     
     
         26 . The aircraft electronics system of  claim 21  further comprising a hardware processor is configured to provide a signal to the switching circuit to conductively couple the charge collection circuit to the measurement terminals. 
     
     
         27 . The aircraft electronics system of  claim 21 , wherein the voltage measurement circuit comprises a differential amplifier to output a voltage differential across the measurement terminals. 
     
     
         28 . The aircraft electronics system of  claim 27 , further comprising an analog to digital converter at an output of the differential amplifier, the analog to digital converter configured to output a digital value of the voltage differential across the measurement terminals. 
     
     
         29 . The aircraft electronics system of  claim 28  further comprising a hardware processor configured to indicate a loss-of-bonding warning for voltage differential measurements larger than a predetermined threshold voltage value. 
     
     
         30 . The aircraft electronics system of  claim 29 , wherein the predetermined threshold voltage value is 0.25 V. 
     
     
         31 . A rotorcraft, comprising:
 an avionics electronics system comprising:
 a charge collection circuit for collecting charge; 
 a switching circuit for discharging the collected charge through a bonding circuit formed between a chassis and a bonding surface; and 
 a voltage measurement circuit for measuring a voltage difference between measurement terminals across the chassis and the bonding surface; 
   wherein the switching circuit comprises a first transistor disposed between the charge collection circuit and the voltage measurement circuit and a second transistor disposed between the field effect transistor and ground.   
     
     
         32 . The rotorcraft of  claim 31 , wherein the first transistor comprises a field effect transistor (“FET”). 
     
     
         33 . The rotorcraft of  claim 32 , wherein the FET comprises a p channel FET. 
     
     
         34 . The rotorcraft of  claim 31 , wherein the second transistor comprises a bipolar junction transistor (“BJT”). 
     
     
         35 . The rotorcraft of  claim 31 , wherein the charge collection circuit comprises one or more capacitors coupled to a voltage source. 
     
     
         36 . The rotorcraft of  claim 31  further comprising a hardware processor is configured to provide a signal to the switching circuit to conductively couple the charge collection circuit to the measurement terminals. 
     
     
         37 . The rotorcraft of  claim 31 , wherein the voltage measurement circuit comprises a differential amplifier to output a voltage differential across the measurement terminals, the aircraft electronics system further comprising an analog to digital converter at an output of the differential amplifier, the analog to digital converter configured to output a digital value of the voltage differential across the measurement terminals. 
     
     
         38 . The rotorcraft of  claim 37  further comprising a hardware processor configured to indicate a loss-of-bonding warning for voltage differential measurements larger than a predetermined threshold voltage value. 
     
     
         39 . The aircraft electronics system of  claim 38 , wherein the predetermined threshold voltage value is 0.25 V. 
     
     
         40 . A method for determining electrical bonding integrity, the method comprising:
 charging a charge collecting circuit;   activating a switch to automatically couple the charge collecting circuit to one or more bonding measurement terminals;   measuring a voltage differential across the bonding measurement terminals;   determining that the voltage differential across the bonding measurement terminals is above a threshold voltage value; and   providing an electrical bonding warning indicator that indicates a loss of electrical bonding subsequent to the determining;   wherein the switching circuit comprises a first transistor disposed between the charge collection circuit and the voltage measurement circuit and a second transistor disposed between the field effect transistor and ground.