Low-power-consumption audio/video recording and communication doorbell
An audio/video (A/V) recording and communication doorbell, including a camera, a speaker, a microphone, a power manager, a battery, an AC/DC rectifier, and a DC/DC converter. The doorbell is configured for connection to an external AC power source through the AC/DC rectifier and the DC/DC converter. The power manager is configured to draw power, up to a threshold power, from the AC power source and to draw supplemental power from the battery such that the power drawn from the AC power source never exceeds the threshold power. The present A/V recording and communication doorbell can thus be connected to an existing household AC power supply and an existing doorbell signaling device without causing inadvertent sounding of the signaling device.
1. A method for sounding a signaling device coupled to an audio/video recording and communication doorbell (A/V doorbell), the method comprising:
maintaining a shunt, connected in parallel to the signaling device, in a low impedance state by closing a shunt switch connected in series with a shunt resistor, the shunt switch and the shunt resistor connected in parallel across the signaling device; and,
switching the shunt from the low impedance state to a high impedance state by opening the shunt switch to trigger the signaling device.
2. The method of claim 1 , wherein switching the shunt comprises increasing voltage across the shunt in response closure of a doorbell switch in the A/V doorbell.
3. The method of claim 2 , wherein closure of the shunt switch occurs in response to a button press of the A/V doorbell.
4. The method of claim 3 , further comprising:
converting A/C power diverted from the A/V doorbell to D/C voltage utilizing a bridge rectifier of the shunt; and
forward biasing control of the shunt switch using a second shunt resistor coupled to the bridge rectifier.
5. The method of claim 4 , the forward biasing control of the shunt switch including biasing a diode of the shunt to cause the shunt switch to open.
6. The method of claim 4 , further comprising:
sensing a rise in the D/C voltage, in response to closure of the doorbell switch, with a first comparator of the shunt;
outputting, from the first comparator and in response to the rise in the D/C voltage, a first-output-voltage that drives the shunt switch to an open position;
sensing decrease in the D/C voltage, in response to the doorbell switch opening, with the first comparator; and,
outputting, from the first comparator and in response to the decrease in D/C voltage, a second output-voltage that drives the shunt switch to a closed position.
7. The method of claim 6 , further comprising:
receiving, at a first input of a second comparator of the shunt, a first voltage having a first maximum equal to an attenuated value of the D/C voltage;
receiving, at a second input of the second comparator, a second voltage having a second maximum (i) equal to a maximum value of the D/C voltage (ii) delayed via a resister-capacitor circuit; and
when the second voltage exceeds the first voltage, outputting, from the second comparator, a grounding signal driving the shunt switch to the closed position.
8. The method of claim 2 , wherein opening the shunt switch comprises forward biasing control of the shunt switch using a bridge rectifier and second shunt resistor.
9. The method of claim 1 , further comprising, using a first comparator of the shunt, sensing a D/C voltage output by a bridge rectifier of the shunt, and causing the shunt switch to close after a first programmable period of time when the D/C voltage rises above a first threshold.
10. The method of claim 9 , further comprising sensing, using a second comparator of the shunt, the D/C voltage, and closing the shunt switch after an additional programmable period of time when the D/C voltage rises above the first threshold.
11. A method for sounding a signaling device coupled to a doorbell, the method comprising:
maintaining, a shunt connected in parallel to the signaling device, in a low impedance state; and,
in response to an increase in A/C voltage across the shunt, switching the shunt from the low impedance state to a high impedance state; and
returning, using a first comparator of the shunt, the shunt back to the low impedance state after a first period of time.
12. The method of claim 11 , further comprising:
converting the A/C voltage to D/C voltage using a bridge rectifier of the shunt;
the switching comprising:
outputting, from the first comparator and in response to rise in the D/C voltage, a first-output-voltage that drives a shunt switch of the shunt to an open position;
the returning comprising:
sensing a decrease in the D/C voltage with the first comparator; and,
outputting, from the first comparator and in response to the decrease in D/C power, a second-output-voltage that drives the shunt switch to a closed position.
13. The method of claim 12 , the decrease in the D/C voltage occurring in response to a doorbell switch of the doorbell opening after press of a button of the doorbell.
14. The method of claim 12 , the switching comprising opening the shunt switch, the shunt switch being in series with a first shunt resistor of the shunt, the shunt switch and the first shunt resistor being in parallel with the signaling device.
15. The method of claim 11 , further comprising converting, using a bridge rectifier of the shunt, A/C power diverted from the doorbell to a D/C voltage, and forward biasing control of a shunt switch using a second shunt resistor coupled to the bridge rectifier, the shunt switch being closed in the low impedance state and open in the high impedance state.
16. The method of claim 11 , further comprising, when the first comparator fails, returning, using a second comparator of the shunt, the shunt back to the low impedance state after a second period of time.