Sigurthr
0
- Joined
- Dec 11, 2011
- Messages
- 4,364
- Points
- 83
Hello everyone,
I want to share the work I just completed last night. I've built a DIY laser with a built in exposure timer to give accurate and consistent exposure times for hologram recording. The laser uses a basic LM317 constant current driver and a simple Monostable Multivibrator or "One Shot" based on the 555Timer IC. The laser runs off one 9V battery (3V Vf + 3V LM317 Dropout + 1.5V 2N4401 Dropout + another 2N4401 used to lop off the remaining 1.5V. 7.5V isn't the easiest to supply with 1.5V cells) and draws just 150mA from the battery.
This is a "50mW" chinese module which is basically just a 3.8mm diode in a 7mm housing and a 5mm diameter lens and spring. I think it cost me about $5. It is certainly far brighter than 50mW and did not lase at the current it was supposed to. It started lasing around 55mA and didn't really kick in until 80mA. I have it running around 120mA. The module (which is barely a heatsink at all) does not get warm to the touch with less than 60sec run times.
DIY Holography Laser - YouTube
With these next two images you can see I had a hard time fitting it all in. Sometimes Ideas are Bigger than Boxes!
I want to share the work I just completed last night. I've built a DIY laser with a built in exposure timer to give accurate and consistent exposure times for hologram recording. The laser uses a basic LM317 constant current driver and a simple Monostable Multivibrator or "One Shot" based on the 555Timer IC. The laser runs off one 9V battery (3V Vf + 3V LM317 Dropout + 1.5V 2N4401 Dropout + another 2N4401 used to lop off the remaining 1.5V. 7.5V isn't the easiest to supply with 1.5V cells) and draws just 150mA from the battery.
This is a "50mW" chinese module which is basically just a 3.8mm diode in a 7mm housing and a 5mm diameter lens and spring. I think it cost me about $5. It is certainly far brighter than 50mW and did not lase at the current it was supposed to. It started lasing around 55mA and didn't really kick in until 80mA. I have it running around 120mA. The module (which is barely a heatsink at all) does not get warm to the touch with less than 60sec run times.
DIY Holography Laser - YouTube
With these next two images you can see I had a hard time fitting it all in. Sometimes Ideas are Bigger than Boxes!