If I remember correctly (always a big "if" at my age) you are running NiteHawk Duals. Those bulbs are physically smaller than the MR16 Luxeon's I found so you can't do a direct swap. I've used the NiteHawk Duals since 2000, and have found them to be reasonably good lights at a very economical price. My 3wLuxeon was $56, plus $20 for the Optronics lamps that I used for the base only, plus $15 for the Mag-lite that I chopped down, and $20 for the battery pack and charger. So for $111 I've built a long running system, then add the $35 tailight, and $24 for the fork mounted marker lights, and $12 for the car horn and button and we reach a total of $182. At least in my hands, home-made does not equal economical.
Nor is it as light weight as a commercial system. With 2 SLA batteries, and my emergency winter gear, my winter commuter weighs in at 57 lbs (yes, 25.9 kg). I try to think of it as training for touring, but I need to tour for that to be real.

With all the stuff I have on my commuter, I try not to think of the weight. To add salt to injury, I carry a 3 lb laptop to work every day. It is comfy, though. I also tour with it. And it's paid for! :D

Nope, mine is the NiteHawk Raptor - the 10W single-bulb setup.

As for expense - I'm a cheapskate at heart! :D I look for cheap deals, and put things together that way.

Minor quibble: the saying is either "to add insult to injury" or "rub salt in a wound". You're metaphore-bashing! ;)

I have always wondered about the visibility of all of my reflective gear. I wear a reflective vest to which I have added an extension with 2 strips of Reflexite to hang further down. On the particular bike I was riding this morning I have two 8-LED truck/trailer marker lights with Reflex lenses which are reflectors even when the lights are off. This morning I was leaving about the same time as my wife so I asked her to let me get a block or two ahead then note how visible I was both with and without the lights on. When I talked to her later she said, "The vest and lights were very visible, but you never turned the lights off." I had. I guess the Reflex lenses work pretty well if she could not tell the difference! With only 8 LEDs each the lights are not nearly as bright as the 54 LED truck brake light on my other commuter, but since they are in a straight line and I have two side by side, they form a quite visible light. The Reflex lenses are an extra benefit. These lights only draw something like .035 amps (verfied with an amp meter) so the two together still draw almost nothing.

For people running non-12V systems...
Found that variable Voltage means that you can use any power source within that range. I love my 18V setup. The battery doesn't bogg me down on the hills.

Rainmanp,
You've been running those lights for...almost a year? Where did you get the Reflex lenses?

Jean,
Sounds like you're ready for some lighter upgrades. My first setup was pretty heavy. But now the bike runs about 22lbs with bottle of water and full lights. Keep going till you get a good solution.

vr, I got the 1284R light shown on this page:
http://www.led-r-us.com/smlights.shtml

It is two pieces with a gasket so wiring connections are well-protected, and it surface mounts with a couple of screws. No pigtail or grommet required. I have been planning to replace this setup with the 5526R shown here:
http://www.led-r-us.com/sttlights.shtml

Since the Reflex seems to work pretty well I may just add a third to my setup. When I made the mount I wanted two lights set wide so I went ahead and made it wide enough for 3 of the 1284R. I even drilled screw holes for mounting 3 even though I was only putting two on at the time. I knew this day would come. The 1284 only draws .035 amp which I confirmed with an amp meter.

Hello from a commuter in Manila, Philippines,

I was hoping I could find opinion on overvolting my 20w 12v MR-11 homemade light.

I have now gone back to using my old 12v 5Ah lead acid since my 4Ah NiMH pack died last month. I found out that only one cell was shorted, the rest are still healthy. While Im still finding time to rebuild the NiMH pack I thought of using 2 of the NiMH cells in series with the lead acid to overvolt by 20%. Actually Ive tried it but only for a few seconds fearing something might explode or something. The light output was way brighter and whiter.

Can this circuit sustain a hour's worth of commute? Or will it be dangerous?

Best regards,

Edgar Jocson

I'm pretty sure I have read in more than one source that it is NOT a good idea to mix battery types like that because of different discharge characteristics. I am no expert, but I would not do it.
FWIW,
Raymond

Ya, I think Raymond's right, I wouldn't do it. I'm not expert either, but that's what I've always read.

I agree, I have read that somewhere too. Don't do it.

It's always good practice to err on the side of caution.

Quick update on my Speedmachine running light project. Here in Ontario all motor vehicles must have daytime running lights, i.e. the headlights are always on day and night. Without getting into the politics of the matter, in my opinion as a cyclist they are a good thing. I can see vehicles approaching from much farther away, both in front and especially in my mirror. It also helps differentiate moving traffic from parked vehicles.

So because I ride this bike on the road my plan is to install daytime running lights. I decided to go with a 12 volt system (actually a 14.8V Li Ion 4 AH pack from Batteryspace.com) because I can use a standard automotive taillight unit, and it give me more flexibility and sufficient watt-hours for long rides. The system will include:

- A LED tail light/stop light. I ordered one each of the red 4" round and 2" x 6" rectangular truck lights from Superbright LEDS and we'll see which shape works best. I took the rack off my bike so the rear lights will be mounted on the back of the seat shell.

- Front and rear turn signals, each unit using 4 of the amber spider LEDs from Quickar wired in series. Not sure if they will be bright enough, but they will run at up to 70 ma., and at 10 cents each I couldn't resist. The idea is that they will normally be steady on, but when I signal a turn the two units on the same side will flash on and off. For housings I have some Cateye TL-LD120FCs that I can use.

- A 1 Watt LED headlight that will be on day and night. I plan to use this one http://tinyurl.com/4caed, but I'll remove the battery box and hook it into the 12V system.

- An instrument light on the handlebar to light my computer and HRM at night. Not sure how to construct this yet.

All this will be hooked into a junction box under the seat that includes a jack for the battery charger and the flasher and battery protection circuits. The battery will fit under the seat shell and will be almost completely hidden. All this will become a permanent part of the bike. For nighttime riding I will build a separate, removable headlight system, something like a 15 - 20 Watt halogen or maybe HID. I've ordered most of the parts but haven't yet received them. I'll post as I progress.

The spider (piranha) LEDs from Quickar arrived today - 120 of them in a little bag. They are for the turn signals and they're fairly bright. I took the photo with room lighting and a desk lamp. The 5 LEDs are in series drawing 70 ma. and the total Vf of the string is almost exactly 10V, so I can use 5 LEDs instead of 4 in each turn signal unit. The Li Ion battery will put out about 16.4V fully charged and there will be a 12V cutoff, so I'll have to use a regulator. Something like a 7812 in a TO220 package should work and they are cheap.

Still thinking about the handlebar switch. I bought a cheap turn signal called a Eurolight to get the switch. It has a master on-off switch with a power LED, a turn signal switch with green signal LEDs and a beeper. If I don't use the switch unit the wire will come in handy.

Uh, my photo seems to have disappeared. How do you post a photo?

Can you give us a source for the Eurolight turn signal switch? As far as posting pictures go, I usually upload them to another photo website and post the url using the insert image icon.

I bought the Eurolight at http://clipbrite2000.net/beamer_2000.htm.

I had trouble with the switch not being waterproof on the clip brite. Hopefully the newer models address this problem.

I remember someone saying that water got in the beeper hole. I just might make up my own switch box.

Here's the photo for msg 640: http://uploads.freeupload.net/users/.../dscn0002r.jpg

Been busy with work so I haven't had much time to spend in the shop. The turn signal flasher circuit is almost finalized. Here's a shot of it on a breadboard:

http://img217.exs.cx/img217/3036/dscn0012r2zg.jpg

On the left side are the 7812 12V regulator, the 2 power MOSFETS (IRFZ34N) and at the very left side buried under the wiring is a 555 timer that generates the flasher signal. On the right are the 4 sets of turn signal LEDs. Each set has 5 Quickar amber Piranha LEDs wired in series. The front and rear pairs are wired in parallel and each side is controlled by a MOSFET. I included a hazard option where all 4 flash together. I gutted the Eurolight handlebar unit, which is made of nice tough plastic, and will use my own switches.

The daytime headlight I'm using http://tinyurl.com/4caed is a sealed unit with a 1Watt LED and a series resistor inside and is designed to be powered by 4 AA cells. In fact it draws just under 300ma at 6V, so connecting it to the nominal 12V electrical system would require adding an external series dropping resistor and wasting that power. Instead I decided to use that excess voltage to power my Warp Drive™. My Warp Drive consists of 2 cyan Luxeon Emitter LEDs connected in series with the headlight. They will be installed inside a minibox mounted on the back of the seat, and will shine down on the back wheel and illuminate the road in that area. Should look awesome at night! Here's a shot of the 2 Emitters in series with the headlight on my bench:

http://img60.exs.cx:81/img60/7509/3s...mitters7yh.jpg

Those babies are really bright. The 3 LEDs in series supplied by a 7812 regulator (the black device with the metal tab on the breadboard) draw about 275ma. which is well below their 350ma. max rating. Here's a closeup of an Emitter:

http://img60.exs.cx/img60/3081/emittercloseup0dd.jpg

It's a little more than 1/4" dia. Did I mention it's bright? I'm still working out how to package all the electronics. There will be a plastic minibox attached to the back of the seat with a tail/stop light and rear turn signals attached, and the battery will be velcroed to the underside of the seat, but I might need a second minibox if there isn't enough room in the first.

Here's the schematic for the battery voltage monitor:

http://img151.exs.cx/img151/7118/batterymonitor2dm.jpg

I'm using a Batteryspace 14.8V 4AH Li Ion pack that puts out anywhere from 16.8V fully charged to shutdown at 12V. I wanted something simple that would tell me the charge state of the battery at a glance. The monitor has a red and a green LED which will be mounted in the handlebar switch unit:

- At full charge the green LED is on and the red LED is off
- At 14.8V (approx. 50% capacity) the red LED starts to light
- At 13.8V both LEDs are on
- At 13.2V (approx. 10% capacity) the green LED turns off and the red LED stays lit

With a different voltage zener diode the circuit will work with other batteries, such as a 12V SLA. I will also incorporate a separate low voltage cutoff circuit that will disconnect the battery at 12V to avoid overdischarging the pack.

By my calculations I should get between 4 and 5 hours of running time on a charge with everything turned on, depending on how much I use the brake. If I turn off the LED headlight and Warp Drive, runtime should be around 10 hours.

Here's the battery and charger:

http://img57.exs.cx/img57/3056/batterycharger6nv.jpg

The lumpiness on the top of the battery is the built-in battery protection circuit board that includes overcharge, overdischarge, and overcurrent protection. Batteryspace says their low voltage cutoff is set to 2.5V which is too low for my liking so mine will shut down at 3V per cell.

Wow that's a small battery! Nice work!

Here's the current version of the complete Speedmachine circuit:

http://img221.exs.cx/img221/8633/spe...atic1074wr.jpg

The main sections are labeled in blue. The flasher oscillator is an LM555 connected as an astable multivibrator. It continuously generates an approx. 1/2 Hz 8 Volt square wave that is applied to the emitters of both 2N3904 transistors. Looking at the left signal circuit at the top of the diagram, the IRFZ34N MOSFET (Metal Oxide Semiconductor Field Effect Transistor) controls the current to the left side front and rear turn signal LED units. Under normal conditions the 2N3904 transistor is turned on, which biases the gate of the MOSFET high, so it conducts and the LEDs get power. The oscillator output has no effect as long as the 2N3904 is conducting.

Now when the left turn signal switch is closed, it brings the base of the 2N3904 low and it stops conducting. This allows the oscillator output to control the gate of the MOSFET, switching it on and off and thereby flashing the left turn signals. The right turn signal works the same way.

The hazard flasher switch clamps the bases of both 2N3904s low, turning the transistors off and applying the oscillator output to the gates of both MOSFETs, causing all four turn signal units to flash on and off in unison. The 1N914 diodes connected to the hazard switch isolate the left and right circuits from each other.

The VN0300L MOSFETS control the turn signal indicators on the handlebar unit. When the IRFZ34Ns are conducting and the turn signals are lit, the VN0300Ls and the indicators are turned off. When the turn signals turn off, the indicators turn on. This 180° phase shift is necessary because under normal conditions (no signalling) the turn signal LEDs are on steady, acting as daytime running lights and contributing to the visibility of the bike in traffic. The turn signal indicators will therefore be normally off and will only light when a turn is signalled or the hazard flasher is on. A small piezo beeper is connected to the drains of the two VN0300Ls through isolating diodes with a trimpot to adjust the volume. The beeper sounds when either left or right or both indicators flash. The beeper will go in the handlebar unit if there is enough room.

I described the battery voltage monitor in my previous msg. The power supply section consists of the battery, a low voltage cutoff (LVC) circuit, and three 7812 voltage regulators. Each regulator supplies approx. 300ma. which is well below the 1 Amp max. rating. Since the headlight/Warp Drive will be turned off only on rare occasions when I need to conserve battery power, I decided not to add a separate switch. Instead I will use the Hi-Off-Low-Off polyswitch that is built into the Nite Hawk Emitter headlight. More details on the LVC later.

Yes, it's light too, only 13 oz. It will nestle in under the seat nicely.

How do drivers react to the signals? Do they understand?