Last afternoon, I had some time and wanted to craft something. I decided, that I need a light flashlight. Since I have to carry a powerbank to my bikepacking trips, I made an USB flashlight:
It is made just from a 1 Watt PowerLED, a LM317 Voltage regulator, some resistors and an old usb cable. These parts are available in nearly every electronics store. If you want to build your own, you can use this link to find out, how much resistance your circuit needs. Just enter the current your LED needs in mA, and you will get the resistance in Ohm. With an USB Port, you can at least run a 2.5 Watt LED. A powerbank should be able to provide a lot more though.
|The circuit before|
|All electronics covered with expoxid resin|
The next step is to make a mount for my bikehelmet, so I can use this solution to save the weight of a
a headlamp. I could also make an usb port facing in the fron direction of my bike, in order to have a bikelight, but on my trips I almost never ride in the dark.