Multi-mode portable lighting device
A portable lighting device, such as a flashlight, with a mechanical power switch and multiple operating modes is provided. The mechanical power switch is disposed in series with the controller for the lighting device and acts as the user interface to the controller to change modes of operation. Because the mechanical power switch is in series with the controller, the portable lighting device does not consume battery power when the mechanical switch is open. A state machine coupled to the controller is polled by the controller each time it is powered up to determine the operational mode of the lighting device.
1. A multi-mode portable lighting device comprising:
a housing for receiving a portable power source having a positive electrode and a negative electrode;
a light source having a first electrode and a second electrode;
a main power circuit for connecting the first and second electrodes of the light source to the positive and negative electrodes of the portable power source, respectively, the main power circuit including a mechanical power switch and an electronic power switch disposed electrically in series with the light source;
a controller electrically coupled in series with the mechanical power switch so that when the mechanical power switch is opened, the controller is not powered by the portable power source, the controller including an output for providing a control signal for controlling the opening and closing of the electronic power switch, the controller being configured to control the electronic power switch in a manner to provide at least two modes of operation;
a state machine having a memory mechanism for temporarily storing a mode of operation and at least one output coupled to the controller for communicating at least one output signal to the controller, wherein said controller is configured to determine the mode of operation based on the at least one output signal from the state machine, and wherein the controller is configured to write a new mode of operation to the state machine following power up;
wherein no current from the portable power source is consumed when the mechanical power switch is opened.
2. A multi-mode portable lighting device, comprising:
a power source;
a light source;
a main power circuit that connects the light source to the power source;
a mechanical power switch that powers on and off the multi-mode portable lighting device;
an electronic power switch;
a controller for providing a control signal for controlling the opening and closing of the electronic power switch, the controller being configured to control the electronic power switch in a manner to provide at least two modes of operation for the multi-mode portable lighting device;
a state machine for temporarily storing a mode of operation and communicating at least one output signal to the controller, wherein said controller is configured to determine the mode of operation based on the at least one output signal, and wherein the controller is configured to write a new mode of operation to the state machine following power up;
wherein no current from the power source is consumed when the mechanical power switch is opened and the mechanical power switch is used to select the mode of operation.
3. The multi-mode portable lighting device of claim 2 wherein the controller remains powered at all times when the mechanical power switch is closed even if the light source is modulated on and off.