9v Battery Flash Light




About: born n raised 765 Indiana. lived in FL 2 years. 5 years of medical school. current ivytech student. went to Rasmussen Ft. Myers FL campus. insomnia. into everything and any craft i can make at all lol

took 9v battery and broke flashlight circuit board and button off a broken flashlight.

Step 1: Solder

solder positive to + and negative to negative

Step 2: Hot Glue It All Stiff and Tight

i put hot glue all around circuit and + wire that hung i glued down an put lanyard on bottom

Step 3: Use As Light or Safety Light or Emergency.

i strapped lanyard to my cycling pack to add night ride so i know im seen i have a head light and rear red blinker but I know ill be seen with these 3 bright L.E.D. lights

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    4 Discussions

    Phil B

    2 years ago

    I am curious about the broken flashlight from which you took the circuit board. Was the voltage input for it also rated at 9 volts? LEDs are rather sensitive to the current levels supplied to them. I recently did an Instructsble on how I added an LED to illuminate the water level in a Keurig coffeemaker. I wanted to use an LED flashlight normally requiring two small 3 volt batteries and I wanted to supply it with an old 9 volt battery removed from a smoke detector. I used a calculator app. for LEDs to learn the value of the resistor I needed to supply no more than 25 milliamperes of current to the flashlight. It worked very well, but could have burned up the LED if I had not properly limited the current with the resistor indicated by the special calculator.

    1 reply
    fullclip765Phil B

    Reply 2 years ago

    it originally took 3 triple AAA batteries a couple bulbs i tried not all worked but i got these three did, still working bright and fine really bright goof for strapping to backpack while commuting on a bike at night, some bulbs just didn't and two strobed and blew lol luck i guess.i have like amillion LEDs