Today on Made To Hack, I retrofit a carbide lamp! I'm doing this for fellow YouTuber Rinoa Super-Genius so that the lamp can be used on an electric ebike project.
Step 1: Cleaning & Taking Apart the Carbide Bicycle Lamp
This is a Luminor Carbide Bicycle Lamp from probably the early 1920s. I'm retrofitting it so that it can run off of 12V DC power as used on an electric bicycle. The first step was to take it apart and clean the inside of the carbide reservoir. The old carbide was removed and everything wiped down and cleaned. I then desoldered the top of the water reservoir from the drip mechanism. I disassembled the front lens and gave it a wipe down. With everything apart, I dry fitted the heat sink for the LED.
Step 2: Drive Electronics for the LED
In order for the heat sink to fit inside the lamp, I had to bend it and trim it down. With the heat sink solved, I moved to the LED driver electronics. The LED is a 12 Volt 9 Watt Chip on Board design on a ceramic substrate. It was stuck on to the heat sink for some thermal tests. I realized that forced air cooling was necessary to keep the LED from overheating. So I worked on fitting a fan behind the heat sink. With the heat sink and LED installed, I ran the LED again and measured the temperature.
Step 3: Wiring Various Parts Together
With the temperature fine, I moved on to running wires to various parts of the retrofit. I also made a new select knob from a piece of brass tubing. Since I wanted this lamp to potentially be used with carbide again in the future, I opted to keep the original select knob and make another. The knob will be attached to this shaft which will be used with a 3 position switch. I drilled holes for the 3 position switch. This one was wired and mounted inside the old water reservoir above the drip mechanism. I used epoxy to glue the shaft to the switch. The water reservoir was then soldered back onto the drip mechanism. The wires for the front lamp were run to the carbide reservoir and soldered as needed.
Step 4: Mounting the LED to the Heat Sink
Since the lamp is meant to be used outside, I decided to conformally coat the LED drive circuit. For this I used a few layers of clear varnish and then glued the drive circuit to the back of the front of the lamp. I cleaned most surfaces with steel wool before the final assembly. I wanted to hide the heat sink behind some brass so that the front looked a bit better. I used some brass strips to make a pattern that surrounded the LED. The final wiring connections were made between the front of the lamp and the body of the lamp.
Step 5: The Final Result
The heat sink and fan assembly was then glued with epoxy to the front of the lamp. The LED was then wired in. And finally the selector knob was soldered into place. I unfortunately did not manage to film the lamp working outside at night. So here it is working inside.
And now it's off to be shipped to Rinoa Super Genius so it can be mounted to an electric bicycle