Mitigating an induced electrical signal from an appliance in a powered-off state
An isolation unit may include input pins to receive an electrical signal induced by ambient sound waves incident on an appliance in a powered-off state, one or more first transformers, connected to the input pins, to electrically isolate the induced electrical, one or more second transformers, connected to the first transformers, to provide a common mode choke function on the induced electrical signal, one or more inductors, connected to the one or more second transformers, one or more resistors, connected to the one or more inductors, wherein the one or more inductors and the one or more resistors are configured to limit an amplitude of a current of the induced electrical signal, and output pins, connected to the one or more inductors, to receive a modified electrical signal from the one or more inductors to propagate the modified electrical signal to a downstream cable.
1. An isolation unit, comprising:
a signal modifier, configured to:
receive, at a plurality of first transformers, an induced electrical signal from an appliance, wherein the induced electrical signal is induced by ambient sound waves incident on the appliance;
modify, by the plurality of first transformers, the induced electrical signal by filtering one or more frequencies of the induced electrical signal to produce a modified electrical signal that may not be transformed into an intelligible audio signal; and
output the modified electrical signal.
2. The isolation unit of claim 1 , wherein the induced electrical signal is one of:
triboelectrically induced by the ambient sound waves incident on the appliance; and
piezoelectrically induced by the ambient sound waves incident on the appliance.
3. The isolation unit of claim 1 , wherein the induced electrical signal is induced by the ambient sound waves incident on the appliance when the appliance is in a powered-off state.
4. The isolation unit of claim 1 , wherein the plurality of first transformers are configured to electrically isolate the induced electrical signal.
5. The isolation unit of claim 4 , wherein the signal modifier further comprises:
one or more second transformers configured to:
receive the induced electrical signal from the plurality of first transformers; and
provide a common mode choke function on the induced electrical signal.
6. The isolation unit of claim 5 , wherein the one or more second transformers are configured to cancel one or more aspects of an amplitude of the induced electrical signal.
7. The isolation unit of claim 5 , wherein the signal modifier further comprises:
one or more inductors configured to limit an amplitude of a current of the induced electrical signal.
8. The isolation unit of claim 7 , wherein the signal modifier further comprises:
one or more resistors in communication with the one or more inductors,
wherein the one or more inductors and the one or more resistors are configured to limit the amplitude of the current of the induced electrical signal.
9. The isolation unit of claim 1 , wherein the plurality of first transformers are configured to attenuate the one or more frequencies of the induced electrical signal in range of from approximately 200 Hz to approximately 10,000 Hz.
10. The isolation unit of claim 1 , wherein the plurality of first transformers are configured to attenuate the one or more frequencies of the induced electrical signal in a range of from approximately 300 Hz to approximately 5,000Hz.
11. The isolation unit of claim 1 , wherein the signal modifier is further configured such that an amplitude of the modified electrical signal is substantially below −120dB.
12. A method of modifying an induced electrical signal that is induced by ambient sound waves incident on an appliance, comprising:
receiving, at a plurality of first transformers of an isolation unit, the induced electrical signal from the appliance;
modifying, by the plurality of first transformers, the induced electrical signal by filtering one or more frequencies of the induced electrical signal to produce a modified electrical signal that may not be transformed into an intelligible audio signal; and
outputting the modified electrical signal.
13. The method of claim 12 , wherein the induced electrical signal is one of:
triboelectrically induced by the ambient sound waves incident on the appliance; and
piezoelectrically induced by the ambient sound waves incident on the appliance.
14. The method of claim 12 , wherein the induced electrical signal is induced by the ambient sound waves incident on the appliance when the appliance is in a powered-off state.
15. The method of claim 12 , wherein modifying, by the plurality of first transformers, the induced electrical signal by filtering one or more frequencies of the induced electrical signal to produce a modified electrical signal that may not be transformed into an intelligible audio signal comprises:
electrically isolating the induced electrical signal by one or more first transformers.
16. The method of claim 15 , wherein modifying, by the plurality of first transformers, the induced electrical signal by filtering one or more frequencies of the induced electrical signal to produce a modified electrical signal that may not be transformed into an intelligible audio signal comprises:
receiving, at one or more second transformers, the induced electrical signal from the plurality of first transformers, and providing a common mode choke function on the induced electrical signal.
17. The method of claim 16 , further comprising:
canceling, by the one or more second transformers, one or more aspects of an amplitude of the induced electrical signal.
18. The method of claim 12 , wherein filtering the one or more frequencies of the induced electrical signal comprises attenuating one or more frequencies of the induced electrical signal in range of from approximately 200 Hz to approximately 10,000 Hz.
19. The method of claim 12 , wherein filtering the one or more frequencies of the induced electrical signal comprises attenuating one or more frequencies of the induced electrical signal in range of from approximately 300 Hz to approximately 5,000 Hz.
20. The method of claim 12 , wherein an amplitude of the modified electrical signal is substantially below −120 dB.
21. The method of claim 12 , wherein modifying the induced electrical signal to produce a modified electrical signal that may not be transformed into an intelligible audio signal comprises:
limiting, by one or more inductors, an amplitude of a current of the induced electrical signal.
22. The method of claim 21 , wherein limiting, by the one or more inductors, the amplitude of the current of the induced electrical signal comprises:
limiting, by the one or more inductors and one or more resistors in communication with the one or more inductors, the amplitude of the current of the induced electrical signal.