Analog Camping Lantern

    Good day! I have long wanted to have a camping, so-called “camping” lantern. Which can be put on / hung over the table, in order to eat not to the touch, well, or a cat to plant for the story of a true story. Of the features required a long time and adjustable brightness.

    A 10W LED, which came from China for a long time, and a lens of a blown LED lamp, came under the arm. As a source of energy, I took a pair of 18,650 at 2500 mA / h each. Then I began to think about the current source for the LED. At first, I wanted to use a microcontroller, but to understand the principles of the implementation of a PWM controller with a throttle was furious. I found a good old DC / DC converter controller - 34063. It remains to run it in “step up” mode with current stabilization.

    The choice of the type of controller was also influenced by a variable resistor with a sink rod, found in the same bins. The limits of the limiting resistors of the brightness control limits have been established empirically.

    To protect batteries from overdischarge, a Chinese module is used to protect batteries against overcharge / overdischarge. To charge the already protected batteries, a Chinese module is also used to charge LiIon. The unreliable microUSB connector was ruthlessly cut off and the power connector removed from the router's dead body was inserted. An indication of the charging status from the module board was brought to the surface. The module itself was cut to a circle with a diameter equal to the diameter of the battery.

    Lantern scheme

    After checking the operation of the converter on the model, the design of the lantern body in FreeCADe began.

    Model in the editor

    From the nuances I note:

    - eye for suspension;
    - controls are displayed on the rear end;
    - recessed power switch, so that you can put the lamp on the surface;

    Printed in blue abs.

    Governing bodies

    Here is a flashlight before final assembly.

    After assembly

    Results: At maximum brightness, the measured current consumption is 500mA. It turns out that in this mode, with a total battery capacity of 5000 mA / h, the operating time will be about 10 hours. With an average brightness consumption is 100 mA, respectively, 50 hours of operation. After field tests I will add article with actual values.

    From the alleged remarks, I will immediately answer:

    - yes, it will get wet if you dip it in water or keep it in the rain for a long time;
    - yes, in the cold LiIon discharges very quickly and does not charge;
    - if you need a model of the case - I can lay out.

    Thank you for reading. Write comments.

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