Creating brake light for a bicycle

[mothrat1980]

Hi,
I've just joined the forum and hoping someone can help with what I am looking for.
I'm looking to design a circuit for my bicycle that will cause my rear light to illuminate when I pull on the brake lever. The way I would like to do this is to have a circuit is place that will cause a reistance in the cicuit to keep the light at a slightly lower level of illumination, and when the lever is pulled, the light increases in brightness. I have a very basic knowledge of electronics, so I think it would involve having the resistance decrease when pulled, however I'm not do not know how to have it wired up so when the contact between the lever and the lever housing is pulled the resistance decreases.
Hopefully my description makes sense and someone can offer advice.

Thank you in advance.
David

 

[ackbarthestar]

Generally, a basic lighting circuit requires a energy source, a switch and a load.
The energy source will be a battery but could be something else such as a small generator.
The switch will be probably attached to the battery somewhere
The load is the lamp
Developing the system would require another switch with either another lamp or a small resistance equivilent to the size of the lamp or slightly larger in parallel with the basic circuit.
This switch mechanism might be a pressure sensor switch enbedded in the rubber brake lining of a calibre braking system.
That's a start you can now do the rest......

 

[shaunfriend]

If you were so inclined, you could just buy one DICONNA XLite100 Waterproof Bicycle LED USB Tail Light Smart Brake Light Sense | eBay - https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F232927292097

 

[PEG]

Hi,if you are having a switching mechanism anyway,i would not have a resistance running constantly,on the tail light circuit,as this would be wasteful.
There are many add-on brake light switching designs,some are built in to lever assemblies,which may be simpler,if it is both levers,operating the light.

As an occasional cyclist,i would say that nobody cares when you brake,but it is turning, which causes abuse and funerals

 

[ackbarthestar]

Hi,if you are having a switching mechanism anyway,i would not have a resistance running constantly,on the tail light circuit,as this would be wasteful.
There are many add-on brake light switching designs,some are built in to lever assemblies,which may be simpler,if it is both levers,operating the light.

As an occasional cyclist,i would say that nobody cares when you brake,but it is turning, which causes abuse and funerals

The resistance or separate extra lamp would only become active when the second switch was activated.

 

[PEG]

Which would mean the brake light was a dimmed version?
A separate or extra lamp,would be ok.

I still reckon a weave indicator lamp,or mount/dismount the pavement lamp,would be more use,to the rest of us

 

[Spoon]

Very crude but this video on Youtube may give you an idea...
There are lots more...

 

[PEG]

Very crude but this video on Youtube may give you an idea...
There are lots more...

Never seen anything so elaborate...he never showed the three led's he put in reversed...his leg muscles must be popping,from dragging a brake so he has a tail light as well...and watching that video,has reminded me that me nan's walking stick,needs a castor on the end...

 

[Spoon]

Never seen anything so elaborate...he never showed the three led's he put in reversed...his leg muscles must be popping,from dragging a brake so he has a tail light as well...and watching that video,has reminded me that me nan's walking stick,needs a castor on the end...

It gives the OP some ideas on what to do.
If I was going to do something similar I would fit the reed switch to the break actuator (or whatever its called) at the back of the bike and stick the battery under the seat.
I only had a quick look at it as I was off to bed just after I posted it.
There are lots on YouTube though.

 

[Rpa07]

That’s the problem with different braking systems now - when we all had callipers or centre pulls we would use the wheel riM as the continuity to activate our rear brake light.
Don’t see the point myself, better off making yourself as visible as possible with Hi biz and rear lights. But that’s my opinion as a cyclist.

 

[Shoei]

Be seen..

and if it's a long ride to the next pub..

 

[gnuuser]

the problem with bicycle tail lighting is not the brightness but the size.
most rear lamps are mounted under the seat but they need to be large enough that the drivers behind them can see the difference when using a turn signal
most designers concentrate on esthetic sizes rather than true functionality.
in order for drivers to see clear differences the will usually have to be too close to stop in time.
for the better part proper reflective clothing and hand signaling is far more effective if both the cyclist and other drivers know them.
for brake lighting however a separate lamp switched by a reed switch and magnet would be simple and effective.
tail lighting (non braking) should be on with the head lamps can be made dimmer by adding a diffusing film between the lamp and lens.
a separate lamp is better for the brake.

 

[Charlie_]

Bi-Filament lamp

 

[gnuuser]

Bi-Filament lamp

there is that!
but in some instances many people are switching to led lamps.
Its all doable in any case but it all depends on how much they want to spend in money or time investment.

 

[Charlie_]

I meant the led type rather than the traditional type