Measuring a voltage to be measured by use of a digital counter means selectively connected to a charged capacitor

摘要

A voltage to be measured is connected to a capacitor means 6 via a switch S1 in order to charge the capacitor. A digital counter means 12 having power supply terminals which are selectively connected via a switch S2 to the capacitor during discharge is used to provide a digital output signal dependent upon the voltage level of the capacitor means at the start of the discharging of the capacitor means. The counter means may comprise at least one toggle circuit adapted to produce output pulses when a sufficient voltage is applied to the power supply terminals. The counter means may comprise at least one ring oscillator. The counter means may be adapted to use thermometer coding. The counter means may be adapted to provide a multi-bit output signal. The voltage to be measured may be from an energy harvesting system 4 which may comprise of a control means for receiving an output signal from the digital counter means and for generating a control signal for controlling the operation of the energy harvesting system.