Automatically restarting a voltage foldback circuit

Patent metadata

Field	Value
Publication number	US-10429866-B2
Application number	US-201715628873-A
Country	US
Kind code	B2
Filing date	Jun 21, 2017
Priority date	Jun 21, 2017
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

Embodiments include techniques for automatically restarting a voltage foldback circuit, the techniques include operating a circuit, and detecting a condition of the circuit. The techniques also include performing a foldback operation based at least in part on the condition of the circuit, subsequently detecting the condition of the circuit. The techniques include initiating a timer of the circuit based at least in part on the subsequent detection of the circuit, and returning the circuit to normal operation based on the timer.

First claim

What is claimed is:

1. A method of automatically restarting a voltage foldback circuit, the method comprises:
operating a circuit;
detecting a condition of the circuit;
performing a foldback operation based at least in part on the condition of the circuit;
subsequently detecting the condition of the circuit;
initiating a timer of the circuit based at least in part on the subsequent detection of the circuit, wherein the timer periodically provides pulses to the circuit if the subsequent detection indicates an overload condition is not removed, wherein the timer is coupled to a current limiting circuit and an output of the comparator via a set of parallel switches, wherein an output of the timer is provided to a first switch of the set of parallel switches, wherein the set of parallel switches are low side switches, the first switch of the parallel switches is connected to and controlled by the timer, wherein the timer receives an output of the comparator, wherein a second switch of the parallel switches is connected to and controlled by the comparator; and
returning the circuit to normal operation based on the timer, wherein returning the circuit to the normal operation occurs while maintaining a load being coupled to the circuit.

2. The method of claim 1 , wherein the initiating the timer is based on the detection indicating an overcurrent condition.

3. The method of claim 1 , further comprises responsive to initiating the timer, the timer periodically sends out a pulse signal to return the circuit to normal operation.

4. The method of claim 3 , further comprises responsive to each pulse being sent by the timer, performing another detection of the condition of the circuit;
returning the circuit to normal operation based at least in part on performing another detection; and
disabling the timer, responsive to the returning the circuit to normal operation.

5. The method of claim 1 , wherein if an overload condition is removed the pulse from the timer restarts the circuit.

6. The method of claim 1 , wherein the timer is an NE555 timer.

7. A system for automatically restarting a voltage feedback circuit, the system comprises:
a foldback circuit, the foldback circuit comprises a current limiting circuit;
a comparator, the comparator is coupled to the current limiting circuit and a timer circuit, wherein the timer circuit is coupled to the current limiting circuit and an output of the comparator via a set of parallel switches, wherein the set of parallel switches are low side switches, wherein the timer circuit periodically provides pulses to the voltage feedback circuit if a detection indicates an overload condition is not removed, wherein pulses return the voltage feedback circuit to normal operation while maintaining a load being coupled to the voltage feedback circuit, wherein an output of the timer circuit is provided to a first switch of the set of parallel switches, the first switch of the set of parallel switches is connected to and controlled by the timer circuit, wherein the timer circuit receives an output of the comparator, wherein a second switch of the parallel switches is connected to and controlled by the comparator.

8. The system of claim 7 , wherein the timer circuit is an NE555 timer.

9. The system of claim 7 , wherein the timer circuit provides a pulse to activate the foldback circuit.

10. The system of claim 7 , wherein the timer circuit is enabled by an output of the comparator.

11. The system of claim 7 , wherein the timer circuit is coupled to the switch via a buffer, wherein the relay receives a pulse signal.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Eberts Chris
• Kostura Anthony

Classifications

• H03K17/284

  in field effect transistor switches · CPC title

• H03K17/0822

  in field-effect transistor switches · CPC title

• H02H3/093

  with timing means {(in general H02H3/027; thermal delay H02H3/085; timing means for undervoltage protection H02H3/247)} · CPC title

• G05F1/571

  with overvoltage detector · CPC title

• G05F1/5735 Primary

  with foldback current limiting · CPC title