Patent ID: 9305443
Filing Date: 2016-04-05
CPC Classification: G08B

Claim Text:
1. A door sensor system comprising: door sensor circuit with a supply voltage terminal, a sensor output terminal, a Zener diode, a first LED (light-emitting diode), a second LED (light-emitting diode), and a first reed switch; wherein the first LED has a first LED anode and a first LED cathode, the second LED has a second LED anode and a second LED cathode, the Zener diode has a Zener diode anode and a Zener diode cathode, wherein the first LED anode and the second LED anode are coupled to the supply voltage terminal; wherein the first reed switch has a first reed switch first terminal and a first reed switch second terminal; wherein the second LED cathode is coupled to the Zener diode cathode and the Zener diode anode is coupled to the sensor output terminal; wherein the first LED cathode is coupled to the first reed switch first terminal and the first reed switch second terminal is coupled to the sensor output terminal; further comprising a sensor support circuit with a comparator circuit, wherein the sensor support circuit is configured for providing a supply voltage V wherein the first LED has a first LED on-voltage V wherein the Zener diode has a breakdown voltage V wherein the values for first LED on-voltage V wherein the comparator circuit has a comparator input that is configured for coupling with the sensor output terminal; wherein the comparator circuit is configured to output a first signal if a voltage at the comparator input is not greater than a first comparator voltage level; wherein the comparator circuit is configured to output a second signal if a voltage at the comparator input is greater than the first comparator voltage level and not greater than a second comparator voltage level; and wherein the comparator circuit is configured to output a third signal if a voltage at the comparator input is greater than the second comparator voltage level.