Patent ID: 9577633
Date: 2017-02-21
CPC Classifications: H03K

Claim:
1. A proximity switch circuit comprising: a DC voltage supply operable to provide a DC voltage, a time domain switched inertial capacitive sensor arranged to provide a thresholding variable capacitance based on the DC voltage; a capacitor; a second voltage supply operable to provide a voltage, V a logic inverter circuit having a logic inverter input and a logic inverter output, said logic inverter circuit being supplied with V a third voltage supply operable to provide a second voltage, V a switch; wherein said time domain switched inertial capacitive sensor and said capacitor are arranged as a capacitive voltage divider between said DC voltage supply and said logic inverter circuit and so as to provide an input voltage V wherein said logic inverter circuit is operable to output an output voltage, V wherein said logic inverter circuit is operable to output V wherein said logic inverter circuit operates in the first state when the input signal is greater than or equal to a predetermined threshold voltage, V wherein said switch is arranged to provide a bias voltage, V