idea for quick and dirty brake light "switch"

Discussion in 'Electrical' started by butterbean, May 1, 2012.

  1. butterbean

    butterbean Well-Known Member

    Haven't tried this yet, but fairly sure it will work. I have an old motorcycle turn signal I plan to use as a brake light. Here is how I plan to activate the light when braking. First, the body of the light is steel. Its the old bolt-on type. I have already drilled a hole in my luggage rack, so the light will be grounded to the rack. I plan to power it with 4 aa batteries in a battery pack. I will wire the light to the battery packs lead, then I will connect a longer wire to the battery packs ground so that it can be run up to the handlebars. My brake lever is an older style all metal type that clamps onto the handlebars with two screws.I plan to make a tab out of a piece of flat aluminum stock and attach it to one of the bolts that holds the brake lever in place so that it extends out parallel to the handlebar. I then plan to drill a hole in the brake lever itself, so that a nut and bolt can be placed through the hole. The nut in bolt is of the type that has a hole in it for a brake cable. I will feed the battery packs ground wire through it, thereby clamping the ground wire to the brake lever. I will insulate part of the end wire so as to make sure that the wire is not touching the lever. When I squeeze the lever, the ground wire will make contact with the tab that I put in place, thereby completing the circuit and activating the brake light. When I release the lever again, the wire will obviously break contact with the tab, thereby breaking the circuit and deactivating the brake light. Thoughts?

  2. butterbean

    butterbean Well-Known Member

    i could also hook the ground wire down by the brake calipers so that when the calipers squeeze together, the wire touches one of them. i will check it out tomorrow and see which idea i like better.
  3. butterbean

    butterbean Well-Known Member

    any thoughts at all?
  4. tooljunkie

    tooljunkie Member

    im thinking of using a pinswitch used on a remote starter hood safety switch.
    or a door jamb switch for a dome lamp in a car.
  5. butterbean

    butterbean Well-Known Member

    I already had all the parts to make my brake light. plus you cant get much simpler than closing and opening a circuit. no actual switch needed, and my brake light is directly activated by squeezing my brake lever. all i needed was a wire and a tab for it to make contact with. probably a lot simpler than trying to fit a switch inside your brake lever or between your handlebar and lever. plus it took hardly any time at all to put together. would have had the whole thing done in probably 20 minutes if my drill didnt die. the best part is the fact that its powered by 4 rechargeable AA batteries.
  6. MikeJ

    MikeJ Member

    Hey Butterbean -

    I offer something I put together a few months back. Attached should be some pictures. The first one shows my horizontal tube just in front of the seat. The tube is electrically isolated from the braking system by a ring of cardboard, like from a cereal box, then surrounded by electrical tape. The cable is my rear brake cable; attached to that is a modified bolt with one wire of the tail light assembly. Around the horizontal tube is one or more cheap hose clamps. Under the hose clamp is a return conductor to the tail light assembly. When the rear brakes are applied, the bolt is dragged over the hose clamps, completing the electrical path to make the tail light shine bright.

    The tail light I show in picture #3 is a replacement for a big truck. It is LED-based, so current draw from the 12 volt 3.3 amp-hour sealed battery is quite low. The light has a half-bright setting, which the average driver can easily see several hundred yards away. When I apply the brake lever, the light goes full bright. I got the light from Harbor Freight.

    My setup is experimental in picture #4, but it works. I included an amber flasher unit from Radio Shack. Be sure to keep the battery anchored so it does not short out on the frame by accident. An in-line fuse is also smart to have. The battery and a charger came from Batteries Plus. A hardware store probably has the same thing.

    This is more costly than what you describe above. But I fully intend to be seen by everyone, to include law enforcement officers, to avoid getting run down. Lots of reflective clothing is worn when I ride at night. And more, but that is included in safety gear stings.


    Attached Files:

  7. butterbean

    butterbean Well-Known Member

    thanks, but its not to hard to be seen at night living in a city. my brake light is done. squeeze the lever, light comes on. release lever, light turns off again. motorcycle turn signal light with super bright LED powered by 4 AA rechargeable batteries rated 1.2v each equals 4.8v. if i put non rechargeable batteries in it would be 6v. it is plenty bright enough to be seen during the day and at night. its not just for night driving. its a brake light. and it works exactly the way I intended it to. total cost to me, zero, since all parts were already on hand and simply repurposed for this project. like i said, quick and dirty, but works. basically just a brake light with a dead man's switch. it works though. tbh i didnt even read your whole reply. too much work when i already have something that works great for me.