scoostraw

I am currently working on a project which includes a vintage 6v dynamo and associated lighting.

The tail-light has me confused. What is the proper way to connect to this kind of a light?

Tourist in MSN

I can't see in the photo if that wire is a one conductor or two conductor wire. Assuming it is two conductors, you plug those two conductors to the taillight wires or plugs at your headlamp.

If that taillight has a single conductor wire, then it is designed for a metal fender and a system where the lights are both grounded to the frame and fork. That gets much more complicated.

The on off switch at the headlamp also turns the taillight on or off. Taillights do not have overvoltage protection, that is in the headlight (modern LED headlights), so you wire the taillight to the headlight instead of to the hub.

If your headlamp is incandescent instead of LED, you do not have any overvoltage protection. And if your tailamp is incandescent, it will be so dim that it is not very good. In this case, if you really want to use these, go ahead but there are better products out there.

You said vintage, it may be best to make sure that everything works before you get down to details of wiring.

Peter White website has very good info on wiring these systems.
https://www.peterwhitecycles.com/wiringinstructions.php

I wrote up a post on how I wired my rando bike, that post is at:
https://www.bikeforums.net/electroni...b-charger.html

scoostraw

Hi. Thanks for the reply. I'm familiar with how to run the wires etc.

What I'm referring to are the two metal connectors on the side of the light. The light is wired to those on the inside (the wires are soldered on).

Was this designed for some type of tiny pins to plug into those small holes? I can't imagine they made it so u have to solder wires to those.

P.S. Big WAVE from Spring Green, WI!

Tourist in MSN

Maybe those two side metal knobs are just for testing it?

2_i 

Can you connect a 6V source to those connectors to see whether the light comes on? Maybe the light came originally with some proprietary connector that is not there anymore and you need to figure out replacement? Are the alu strips inside the fender used as a stand-in for wires? SKS was pushing such a system in the past and it worked poorly in practice, with galvanic corrosion developing around the connectors, in particularly inside the fenders. Is there a brand name somewhere on the light?

scoostraw

It's possible.

After opening up the light, it looks like the mounting stud does make the connection to the fender. And the "hot" connection looks to me made thru a small hole in the end.

It also looks to me like they made this to be a 6V negative ground system. Today I will grab a 6v battery and see if anything works.

scoostraw

I figured it out (I think)!

This light appears to be a BUMM339.

There is a main bulb, which lights and turns off when power is removed. There is another light below that (an LED possibly?) which remains lit when power is removed (ie. if the cyclist is stopped at a traffic light).

This secondary lamp is kept on via a capacitor that is charged up. The leads from that capacitor are connected to those 2 small posts on the side. So if for some reason you want to turn the light completely off without waiting for the capacitor to discharge, you can just short out those 2 terminals and the light goes out.

Tourist in MSN

I have a B&M light that has a push button to short out the stand light to turn it off.

The bulb looks like an incandescent bulb. That makes sense when it says at the bottom, 6V and 0.6W, as taillights in the sidewall generator era were 0.6 watt incandescent bulbs.

I would not be surprised if the bulb operates on AC but a rectifier is need to make DC for the stand light.

There are LED bulbs to replace incandescent bulbs, but I think they only work on DC, meaning if you tried one it would likely flicker at slow speed. But I do not know the best source for those, I tried ordering some on line and they were quite dim.

Is your headlight also incandescent? If so, it would be 2.4 watt, 6 V.

scoostraw

I determined that the dynamo on this bike is not working. I had a dynamo from another bike, and that one doesn't work either.

So I decided to go with battery power for lighting. I just ordered one of these from Amazon: (The battery on this bike is 24V)

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

2_i 

So are you trying to use this on an electric bike? Are you sure that you are testing the dynamos correctly? While the dynamos are not overly robust devices, finding two dead one after another sounds suspicious. Are you sure that it is worth fighting for that light? They run at 6 euros on German Ebay.

scoostraw

I screwed up!! I had my meter on DCV when I tested them.

So yes the original dynamo is good. I Just need some 18 gauge wire and I can wire everything up.

This is what I am working on. It is a wheelchair bicycle:

2_i 

Old-style bottle dynamos are inefficient and produce quite a bit of resistance when working. The incandescent light you plan to use is inefficient too. This looks like an electric assist bicycle. Is it right? In that case it would make more sense to use a way more efficient LED light, preferably made for electric bikes, and power it directly from the battery there. If you still wanted to use the light(s) you already have, for a regular bicycle, then the converter you ordered, might be your best next option. Note that you are hit with an inefficiency price each time you convert between energy forms, electric and mechanical.

scoostraw

Hi. Yes I'm aware of how inefficient dynamos are. I just decided to leave things as they are.

No this unit is not electric assist. It has a throttle and can run on electric only.