Current measurement for an electric heater

摘要

The invention relates to a method for measuring a current or voltage output quantity of a switched-mode power supply circuit (H), referred to as a chopper circuit, of period T and of cyclic ratio α, belonging to the interval]0; 1[, such that, at each period, the supply current is non-zero during an “ON” phase of duration αT, and zero during an “OFF” phase of duration (1−α)T. The measurement method includes the following steps: measuring the value Gon of an image of the output quantity during an “ON” phase; measuring the value Goff of an image of the output quantity during an “OFF” phase; calculating the difference ΔG=Gon−Goff; and using the difference ΔG for evaluating the output quantity.

主权项

1. A method for measuring a current or voltage output quantity of a switched-mode power supply circuit, called chopper circuit, of period T and of duty cycle α, belonging to the interval]0; 1[, such that, at each period, the power supply current is non-zero during an on phase of duration αT and zero during an off phase of duration (1−α)T, wherein the measurement method comprises the following steps:
measuring the value Gon of the current or voltage output quantity during an on phase; measuring the value Goff of the current or voltage output quantity during an off phase; calculating the difference ΔG=Gon−Goff; and using the difference ΔG to evaluate the current or voltage output quantity.