State cycling apparatus and method, and control circuit for a lamp

摘要

A state cycling apparatus uses a capacitor instead of complicated and expensive microcontroller to fulfill a state cycling function of a system. The state cycling apparatus includes an internal circuit in the system connected to the capacitor. In a first embodiment, the internal circuit reads the voltage level on the capacitor at power on to determine a current state for the system, and writes the voltage level corresponding to a next state of the system to the capacitor. In a second embodiment, the system reads the state data stored in the internal circuit to determine a current state for the system at power on, the capacitor is charged during the system is under power on, and the capacitor provides power for the internal circuit to store a state data after the system is powered off.

主权项

1. A control circuit for a lamp, comprising:
a capacitor; and a controller connected to the capacitor, switching the lamp between a plurality of states including a flashing state, and charging and discharging the capacitor to generate an oscillating frequency as a flashing frequency of the lamp during the flashing state; wherein the controller reads a voltage level of the capacitor, switches the lamp to one of the states according to the voltage level, and writes another voltage level corresponding to a next state to the capacitor when the lamp is powered on.