DEVICE FOR DETECTING THE STATE OF A SWITCH

• US 20100052705A1
• Filed: 04/03/2007
• Published: 03/04/2010
• Est. Priority Date: 04/04/2006
• Status: Active Grant

• Current Assignee: Airbus Operations SAS (Airbus SE)
• Original Assignee: Airbus France
• Inventors: Bonnet, Guillaume, Dulaur, Mathieu
• Granted Patent: US 9,064,649 B2
• Time in Patent Office: Days
• US Class Current: 324/705
• CPC Class Codes: H01H 1/605 Cleaning of contact-making surfaces by relatively high voltage pulses
• CPC Class Codes: H01H 71/04 Means for indicating condition of the switching device by means of an auxiliary contact H01H71/46
• CPC Class Codes: H01H 9/167 Circuits for remote indication
• CPC Class Codes: H02H 3/04 with warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned watching of pilot wires H02H1/0084; protection of protective arrangements H02H7/008; indication of the state of electronic switches H03K17/18

Abstract

A device for detecting the state of a switch. The device includes a detection circuit which delivers a signal of specified value (V_pullup) when the value of an electrical quantity (R_Sw) characterizing the state of the switch is less than a threshold called the lower threshold (R_closed) and/or a signal of different value when the value of the electrical quantity is greater than a threshold different from the lower threshold, called the upper threshold (R_open). The disclosed embodiments also concern flight control systems, in which the device is implemented, and the aircraft including the systems.

Claims

1. A device for detecting the state of a switch, including a switch and a feed circuit of said switch, comprising a detection circuit 4 which delivers a signal of specified value (V_pullup) when the value of an electrical quantity (R_Sw) characterizing the state of the switch is less than a threshold called the lower threshold (R_closed) and/or a signal of a different value when the value of said electrical quantity is greater than a threshold different from the lower threshold, called the upper threshold (R_open).

3. A device according to claim 1, further comprising that said electrical quantity is the resistance R_Sw of the switch and that the detection circuit delivers a signal when the value of the resistance is less than a lower resistance threshold (R<

R_closed) and/or a signal of different value when the value of the resistance is greater than an upper resistance threshold (R>

R_open).

4. A detection device according to claim 1, further comprising that one of the signals indicates the closed state and the other signal the open state.

5. A detection device according to claim 1, further comprising that the detection circuit delivers as output two values of different amounts, a first value for which the switch is considered to be in the closed state, when the resistance R_Sw is less than a first resistance threshold (R<

R_closed) and a second value for which the switch is considered to be in the open state, when the resistance R_Sw is greater than a second resistance threshold (R>

R_open).

6. A device according to claim 3, further comprising an adjustment circuit which delivers a voltage, a function of the value of the input switch resistance of said detection circuit.

7. A device according to claim 3, further comprising that the detection circuit includes a hysteresis circuit which delivers a first output-voltage value (V_D=V_pullup) for an input voltage less than a first voltage threshold (V_{Hy High}) and a second output-voltage value (V_D=0) for an input voltage greater than a second voltage threshold (V_{Hy Low}).

8. A device according to claim 6, further comprising that the adjustment circuit includes a resistive bridge which delivers an output voltage, a function of the value of the switch resistance, as well as including resistances and a feed.

9. A device according to claim 1, further comprising that the hysteresis circuit includes a feed and resistances with values such that it provides a current allowing the contact of the switch to be cleaned.

10. A flight control system, comprising a device according to claim 1.

11. An aircraft, comprising a device according to claim 1.

2. A device for detecting the state of a switch, further comprising that the value of said electrical quantity (R_Sw) is between the lower-threshold value and the upper-threshold value or is equal to these values, the circuit delivers a signal identical to that of the previous state.