Solenoid fast shut-off circuit network

Patent metadata

Field	Value
Publication number	US-10637469-B2
Application number	US-201715654430-A
Country	US
Kind code	B2
Filing date	Jul 19, 2017
Priority date	Jul 19, 2017
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

A fast shut-off solenoid circuit network includes a solenoid circuit and a current dissipation circuit. The solenoid circuit is operable in response to an electrical current, and configured to operate in an enable mode and a disable mode. The current dissipation circuit is configured to dissipate the current discharged from the solenoid circuit in response to invoking the disable mode. The fast shut-off solenoid circuit network further includes a dissipation bypass circuit. The dissipation bypass circuit is configured to divert the current discharged by the solenoid circuit away from current dissipation circuit when operating in the enable mode.

First claim

What is claimed is:

1. A fast shut-off solenoid circuit network comprising:
a solenoid circuit operable in response to an electrical current, and configured to operate in an enabled mode and a disabled mode;
a low-side switch;
a pulse width modulation (PWM) circuit configured to generate a pulsed output signal that continuously switches the low-side switch between an on-state and an off-state during the enable mode to adjust a level of the current flowing through the solenoid circuit, and maintains the low-side switch in the off-state during the disable mode;
a current dissipation circuit configured to dissipate the current discharged from the solenoid circuit in response to invoking the disable mode; and
a dissipation bypass circuit configured to divert all of the current discharged by the solenoid circuit entirely away from the current dissipation circuit when operating in the enable mode.

2. The fast shut-off solenoid circuit network of claim 1 , wherein the dissipation bypass circuit diverts the current discharged from the solenoid circuit during the off-state of the low-side switch.

3. The fast shut-off solenoid circuit network of claim 2 , wherein the dissipation bypass circuit includes a bypass current path switch that blocks the current from flowing through a first current path so as to divert all of the current discharged from the solenoid circuit entirely away from the current dissipation circuit when operating in the enable mode, and flows all of the current through a second current path that diverts all of the current directly to the current dissipation circuit in response to invoking the disable mode.

4. The fast shut-off solenoid circuit network of claim 3 , further comprising a current path control circuit that commands the bypass current path switch to select the first current path in response to receiving a first control signal having a first voltage value, and commands the bypass current path switch to select the second current path in response to receiving a second control signal having a second voltage different from the first voltage.

5. The fast shut-off solenoid circuit network of claim 4 , wherein the current path control circuit includes a metal oxide field effect transistor (MOSFET) comprising:
a source terminal in signal communication with the first current path; and
a gate terminal configured to selectively receive the first control signal having a first voltage and a second control signal having the second voltage greater than the first voltage,
wherein the MOSFET forces the bypass current path switch to select the first current path in response to receiving the first control signal, and forces the bypass current path switch to select the second current path in response to receiving the second control signal.

6. The fast shut-off solenoid circuit network of claim 5 , further comprising an electrical hardware controller in signal communication with the gate terminal of the MOSFET and the PWM circuit, the controller configured to output the first and second control signals based on at least operating condition.

7. The fast shut-off solenoid circuit network of claim 6 , wherein the controller outputs the first control signal when detecting normal operating conditions, and outputs the second control signal when detecting at least one fault condition.

8. The fast shut-off solenoid circuit network of claim 3 , wherein the current dissipation circuit includes a Zener diode interposed between the solenoid circuit and the bypass current path switch, the Zener diode configured to dissipate the current discharged from the solenoid circuit in response to invoking the disable mode.

9. A method of dissipating energy stored in a solenoid circuit, the method comprising:
delivering electrical current to a solenoid circuit that is configured to operate in an enable mode and a disable mode;
continuously switching a low-side switch configured between an on-state and an off-state during the enable mode to adjust a level of the current flowing through the solenoid circuit;
generating a pulsed output signal, via a pulse width modulation (PWM) circuit, that continuously switches the low-side switch between the on-state and the off-state during the enable mode; and
disconnecting the pulsed output signal in response to invoking the disable mode such that the low-side switch is maintained in the off-state
dissipating the current discharged from the solenoid circuit, via a current dissipation circuit, in response to invoking the disable mode; and
diverting all of the current discharged from the solenoid circuit entirely away from the current dissipation circuit, via a dissipation bypass circuit, when operating in the enable mode.

10. The method of claim 9 , wherein the dissipation bypass circuit diverts the current discharged from the solenoid circuit during the off-state of the low-side switch.

11. The method of claim 10 , further comprising inhibiting, via a bypass current path switch included in the dissipation bypass circuit, the current from flowing through a first current path so as to divert the current discharged from the solenoid circuit entirely away from the current dissipation circuit when operating in the enable mode, and flowing all of the current, via the bypass current path switch, through a second current path so as to divert all of the current directly to the current dissipation circuit in response to invoking the disable mode.

12. The method of claim 11 , further comprising commanding, via a current path control circuit, the bypass current path switch to select the first current path in response to receiving a first control signal having a first voltage value, and commanding the bypass current path switch to select the second current path in response to receiving a second control signal having a second voltage different from the first voltage.

13. The method of claim 12 , further comprising:
forcing the bypass current path switch to select the first current path and deliver the discharged current to a source terminal of a metal oxide field effect transistor (MOSFET) in response to delivering the first control signal to a gate terminal of the MOSFET; and
forcing the bypass current path switch to select the second current path such that the discharged current is blocked from flowing through the MOSFET and is delivered directly to the current dissipation circuit in response to delivering the second control signal to the gate terminal.

14. The method of claim 13 , outputting the first and second control signals, via an electronic hardware controller, based on at least operating condition determined by the controller.

15. The method of claim 14 , further comprising outputting the first control signal when the controller detects normal operating conditions, and outputting the second control signal in response to the controller detecting at least one fault condition.

16. The method of claim 11 , further comprising, in response to invoking the disable mode, dissipating the current discharged from the solenoid circuit using a Zener diode connected between the solenoid circuit and the bypass current path switch.

Assignees

• Hamilton Sundstrand Corp
• Hamilton Sunstrand Corp

Inventors

• Wilson Michael A
• Parra Eduardo Ahuactzin

Classifications

• H02H9/047

  Free-wheeling circuits · CPC title

• H01F2007/1888

  using pulse width modulation · CPC title

• H02M7/527

  by pulse width modulation · CPC title

• H01H47/32

  Energising current supplied by semiconductor device · CPC title

• H03K17/0822

  in field-effect transistor switches · CPC title