5-conductor cable source?

[cgeiser]

Hi all. After building one of Martins simpler circuits I'm ready to move on to the full wave/ voltage doubler. The problem I'm having is sourcing the 5-conductor cable from the circuit (housed in steerer tube) to the light. The circuit requires a switch which I would like to put in the light head. This will require 1x switch input, 2x switch output back to the circuit board in steere tube, and 2ore conductors back up to the light to power the LED's.

All sources I've found for a flexible outdooor (waterproof) rated wire require an order of 1000' or so. Anyone have another source for this wire, in an 18 or 20 AWG. Would 22AWG be acceptable?
Thanks,
Che

 

[BrianMc]

I have Martins circuit 12 voltage doubler/switching board. A switch is not actually required. You could unplug at the dyno or run lights in day as a safety thing. If you do want to shut the unit off without unplugging at the hub, you need to interrupt only one side of the dyno's output, that is one wire to the light head and another back. Plus the two led leads. No reason you could not just tape two 2-conductor cables together. Maybe 4 conductor cable is easier to find. Instead of a light mounted switch, I have a bar mounted switch.

BrianMc

 

[Norm]

Would trailer cable be suitable? Here in Australia it's available in 5 and 7 core.
Norm

 

[cgeiser]

I'll have to look at the circuit again but I believe the switch selects between two circuit paths to allow for high enough voltage at low speed and higher current at higher speeds. I'll look into the trailer wire - hopefully its diameter is small enough to match nicely to a small light head.
Thanks for the tips,
Che

 

[BrianMc]

I'll have to look at the circuit again but I believe the switch selects between two circuit paths to allow for high enough voltage at low speed and higher current at higher speeds. I'll look into the trailer wire - hopefully its diameter is small enough to match nicely to a small light head.
Thanks for the tips,
Che

You are likely correct. Mine does that mode switching based on hub frequency (to judge speed), automatically. I forgot about the manual version.

If you are OK heat shrinking a cover, and if you can get enough length, I have used cables from a defunct PC power supply.

BrianMc.

 

[znomit]

You have plenty of room in the steerer tube for components so just go with circuit 8 or 9 if you must locate in the steerer. I usually do circuit 10 but put everything except the lighthead into a small box under the stem.
Actually the last few builds were just two LEDs and a simple full wave, bright enough and good low speed performance.
http://www.pilom.com/BicycleElectronics/DynamoCircuits.htm#DualMode

 

[cgeiser]

Znomit-
Is the full wave the same as the voltage doubler? To get the low speed performance with 3 LED's it seems like I'll need the voltage doubler, but I'll sure lose a lot of potential power if I can't switch the doubler off when going fast enoug lh to not need it.

My plan has been the circuit 8 in the steerer tube, which is why I'm looking for a 5-conductor cable.

 

[znomit]

Znomit-
Is the full wave the same as the voltage doubler? To get the low speed performance with 3 LED's it seems like I'll need the voltage doubler, but I'll sure lose a lot of potential power if I can't switch the doubler off when going fast enoug lh to not need it.

My plan has been the circuit 8 in the steerer tube, which is why I'm looking for a 5-conductor cable.

Circuit 8 needs only 4 core which might be easier to source. 2 for switch and two for LED.

Full wave is just the rectifier and smoothing cap, add the boost from circuit 7 if you like.
For the road bike I find two LEDs is plenty at speed and still lights down to 5kph which is slower than I go on the bigger hills. I've built dyno lights using 1 - 5 LEDs and two is OK.
For the MTB I use a triple LED and not so good at slow speed but I nearly always run a helmet light. If you're building C8-C10 for a MTB you'll find its pretty annoying having to change modes suddenly when a log appears on the trail and you slow down.