1. Field of the Invention
The present invention relates to electrical switches, and particularly to an electromagnetic induction switch circuit.
2. Description of Related Art
An ordinary laser pen includes a battery, a working circuit comprising a laser diode driver (LD driver) and a laser module, and a switch for selectively coupling the battery with the working circuit. Users can turn on and turn off the laser pen by operating a button, which connects to the switch.
Therefore, users must manually press the button to turn on the laser pen when they want to use it, and have to press the button again to turn off the laser pen when not using it, to save power. It is inconvenient for users to operate the switch when they use the laser pen frequently. Oftentimes, users forget to turn off the laser pen when not using it, which results in waste of power.
Therefore, an electromagnetic induction switch circuit which can automatically turn a laser pen on or off is needed.