Here are links to Seth Jayson's instructions for making a low-budget light system:

http://members.cox.net/sethjayson/index.htm

http://members.cox.net/sethjayson/SBBS3.htm

Here is a discussion by Richard Flotard, originally in an email to me, posted with his permission. In the meantime, Seth updated his discussion, so some of the following discussion might not apply any more:

I thought you might like a follow-up on how well Seth Jayson's 20 Watt homemade bike light system worked for me on the WW 3.4. I have the light mounted on the derraileur post and the battery on the platform formed by the frame behind the seat. It works great and the total cost was about 25 dollars and an hour or two for construction time. You can go to Seth's website by going back to 11/24/03 in general discussion on bentrideronline and clicking on "Make yer own light" Print out a copy of his instructions as I think this will disappear from the listings before long. The only modification I had to make to Seth's plans was to first mount the lamp holder on a 1" metal C clamp intended for attaching electrical conduit to a wall instead of mounting the holder directly to the hose clamp on the frame. I used the variety that has only one screw hole instead of two as in a U-clamp. The really lightweight versions used for securing water pipes to house frames are too easy to bend (I tried that kind first). I used Seth's mounting system to mount the C clamp to the frame - this consists of a hose clamp with a hole drilled in it for the mounting bolt - in my case the bolt was just long enough to mount the C clamp to the hose clamp. I drilled a hole in the C clamp at the point necessary to keep the lamp holder horizontal. If you don't get it just right, it is possible to bend the C clamp a little to change the vertical position of the beam. Just be sure to take the C clamp off the frame first before trying to bend it. The batteries are in parallel and are bound together and tied to the frame using some 1/4" elastic (bungy) cord until I figure out if I need a more secure mounting. So far I have ridden about 30 miles without having any problem. The light looks unusual but good, not as though it were thrown together from a bunch of parts. It sure makes the trike visible from a distance! The parts I used and the approximate cost of each PVC compression fitting from Home Depot $2.49 Lamp from Home Depot - 20W halogen $5.99 Two 12 volt 2.3 Ah Sealed lead acid batteries $6.00 ea + shipping (American Science and Surplus website) 25 feet of speaker wire - 99cent Only Store $1.07 (used about 1/3) Hose clamp (had in my used part bin) C-clamp for electrical conduit Home Depot $ 1.29 (pkg of 4) 6 each Female disconnects - 18 ga wire $.89 6 each Male disconnects - 18 ga wire $.89 toggle bolt 1/4" by 1/2" Home depot $.08 toggle bolt 1/4" by 1 1/2" Home Depot $.12 1/4 " nut and 1/4" wingnut (used part box) Second hand 12 volt 300 ma plug in power source $2.00 I found an old AT$T unit for one of their cordless phones. I just searched the secondhand stores until I found one that delivered 12 volts DC and 200 to 300 ma current. You might need a volt meter to check the polarity of the wires before hooking the battery to the charger. You can also use a 12 V car battery charger but the output of a conventional charger is very high compared to the amount you need for charging and it is a waste of electricity. It is also a pain to work with the big wires coming out of the regular charger. The batteries I used were intended for an emergency lighting source so they have a built in charge limiter and can only be completely charged overnight. I expect the battery to discharge in about 2.5 to 3 hours used with the 20W bulb. You could switch to a 10W bulb and get twice the (time.)

Richard D. Flotard

Now here is another discussion from Richard, this time with photos, again posted with his permission::

Here is a file containing three pictures showing how I mounted the Seth Jayson BS headlight to the WW 3.4. The fourth picture shows how I managed to get the magnetic sensor for my el cheepo nashbar computer close enough to the wheel-mounted-magnet to have it work. I couldn't find my spare elastic cord to tie down the battery, so the battery is currently held in place with miscellaneous cotton fiber cord and a loop of old bike tube. I did glue some gambling table felt (not visible in pictures) to the bottom of the batteries to keep from scratching the paint. That may be a little harder to come by outside of Sin City. The readout sits on the left side of the handlebar, easily visible while riding. I did have to lengthen the cord by adding a section of wire taken from an old set of Christmas lights. Christmas light wire is tough and just the right current carrying capacity to add to the existing cord. I would recommend soldering the connections and using shrink tubing to insulate the connections. The splice is under the frame so the green color of the Christmas light wire is not noticeable to observers. The sensor mount is a length of 1" diameter, schedule 40 irrigation pipe with a notch cut in one end. I made the notch oblong using a round file. I wrapped the WW frame member with a protective cover of red 3M vinyl tape to make the pipe fit snugly over the frame but still not scratch it. The pipe is held in place laterally with a small piece of elastic cord wrapped around the frame from the side. The fine spacing between the frame and the plastic pipe is accomplished by using one or more cork circles used to cushion cabinet doors as the doors are closed against the cabinet frame. I cut four holes in the side of the pipe facing the spokes to attach the sensor to the pipe with cable ties. The sensor has stayed in place and has worked perfectly for over 1000 miles so I guess it must be a suitable attachment. Don't want to make you feel bad, but yesterday was so nice I was able to ride in a T-shirt. Pretty unusual for January, even here. You can make me feel bad in turn by commenting on how nice it is in Michigan in July when it is 120 in the shade here! The odometer passed the 1000 mile reading during the ride.

The photos: