BEAM Projects > Solar Roller


Solar Roller - Finished!

High Efficiency Competition Power Smart Solar Speeder V2 by Wilf Rigter

Circuit used: High Efficiency Competition Power Smart Solar Speeder V2 by Wilf Rigter

Construction Notes: The hardest part for me was coming up with a design for a chassis. I opted for an old standby...Legos. The motor is from a salvaged DVD player ( see my E-Salvage 102 write up to see where it came from). I want to do the circuit up on a perf-board. However, I am fresh out. Looks like a Monday trip to get some.

September 6, 2008: I started gathering my parts and realized I was missing a few things. I thought that I had a 1381E (this datasheet includes all of the 1381 family), but I did not have any I have 1381C's and 1381G's... So I opted for the G. The trigger voltage is rated at 2.4v, and it should actually trigger in this circuit at 2.6v. Not a bad compromise. I also had to substitute the diode D1 for a 1N914. Looking at the data sheets for the original 1N4148 and comparing it t the 1N914, I think it is a good subsitute. I have a 5.5v/1F supercap that I am going to try and use for the storage cap. If it takes too long to charge, I may have to change it out. I also decided on a bigger solar cell than I had originally planned. I found an older Panasonic BP-373334. It is 1.25" x 1.5" in size and it puts out 5.5v. I really wish I could find some more of these cells! I am going to start soldering it up later today or tomorrow.

September 7, 2008: I got most of it soldered up (see the pictures below). I just need to add the motor leads, storage capacitor and solar cell. I am going to trim down the circuit board after I finish it. I am shooting to get this finished off by mid week.

September 14, 2008: I finally had most of the engine assembled (minus the solar cell, storage capacitor and motor). I decided to test the it and found that it took almost 8 minutes to charge up the storage capacitor to firing voltage. When it fired, it ran for a long time (this is great); however, after that first firing, I never could get the capacitor to charge above 1V. It just hovered around the 1V mark...So, after checking all of my solder connections (for bad joints and shorts) and the schematic again, I figured I must have damaged a component. Rather than remove each one and test, I am going to re-build it (that will be alot faster - I hope). I am also going to use a .22F super capacitor. It looks just like the original 1F capacitor, but lots smaller and testing shows it charging in 1-2 minutes. Pictures will be uploaded soon.

September 20, 2008: I finally had time to finish this one up. After rebuilding the engine twice, I finally figured out what what going on. I would get only one really long burst (note the white dot on the pully - makes it a bit easier to see it rotating), then nothing. According to my voltmeter, the capacitor was charging to .67V and hovering. I suspect it is something with the motor I am using. If I totally discharged the capacitor, I could get it to work once, then I would have to discharge it again. A bit annoying, but workable. I really like the .22F capacitor, it charges fast and discharges quickly as well. I get almost 2 meters out of it when it fires. Besides the frustration, it was a lot of fun. Also, check out the for some larger pictures. Time to start looking for the next project!

Most of the Parts

Backside of Solar Cell

Circuit Board - Top

Solar Roller - Front View

Solar Roller - Front View

Solar Roller - Left Side

Circuit Board - Bottom


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