Determining power stealing capability of a climate control system controller

摘要

Disclosed are exemplary embodiments of systems and methods for determining a power stealing capability of a climate control system controller. In an exemplary embodiment, a controller for use in a climate control system generally includes a capacitor chargeable by current flowing through an off-mode load of the climate control system. A voltage detect circuit detects a voltage across the capacitor. The controller includes a timer for determining a charge time of the capacitor from a first specific voltage to a second specific voltage based on input from the voltage detect circuit. The controller determines a resistance of the off-mode load based on the charge time and, based on the determined resistance, determines a level of current for power stealing through the off-mode load.

主权项

1. A controller for use in a climate control system, the controller comprising:
a capacitor chargeable by current flowing through an off-mode load of the climate control system; a voltage detect circuit for detecting a voltage across the capacitor; and a timer for determining a charge time of the capacitor from a first specific voltage to a second specific voltage based on input from the voltage detect circuit; the controller being configured to determine a resistance of the off-mode load based on the charge time and based on the determined resistance, to determine a level of current for power stealing through the off-mode load; and wherein the resistance of the off-mode load is determined in accordance with:
Vt=V0+(V1−V0)×(1−e−t/RC) where Vt represents a voltage across the capacitor at a time t, R represents a circuit resistance that includes the resistance of the off-mode load, C represents capacitance of the capacitor, and V0 and V1 represent the first and second specific voltages.