Combined signal, brake and tail light

[audioguru]

It is illegal in many countries to tamper with the lighting on a vehicle especially when you do not have a clue about required brightness and viewing angle.
Some teenagers buy cheap Chinese lights for their cars that cannot be seen at night. Or are the brake lights turned on all the time?

 

[KeepItSimpleStupid]

No turn would override brake but only on the active side.
There is no park circuit to the front lights and probably should be disregarded for the rear lights as it isn't an issue and muddies up the project

The thing is the 4x design is the same, EXCEPT brake and park are exchanged on the front and rear of the car. Same signal, just a different use.

No turn would override brake but only on the active side.

Don't quite understand this. What I mean is that you would have one brake on and one of the brake lights flashing in the rear when the turn signal is on.

and if park and turn are shared in the front, then the same thing happens. Turn makes one of the parking lights blink, so one is on and the other is blinking.

My boss could play chess with another person while watching dishes and not seeing the board and for driving "fun", he would prime factor license plate numbers.

So, one circuit, multiplied 4x; Two use the brake signal and two use the parking signal.
The sides are "tied" together with the relay coils that operate the left and right turns on the side of the car.

 

[3Ds]

It is illegal in many countries to tamper with the lighting on a vehicle especially when you do not have a clue about required brightness and viewing angle.
Some teenagers buy cheap Chinese lights for their cars that cannot be seen at night. Or are the brake lights turned on all the time?

Seem kinda grumpy for a Canadian eh?
Actually I agree. It's annoying seeing all the kids putting black acrylic over their lights. Just waiting for an accident. Kids will do some funny things. You're in Audio, are you old enough to remember "Mind Blower" speakers? They were amplified 6x9's that contributed to my "cluelessness".
Not really relevant with this project though. Although "clueless" I do know these lights will be brighter and viewable at greater angles than the "guy sticking his hand out the window" type signals that it came with...
Cheers

 

[audioguru]

I remember when the "turn signal" on a horse and buggy was a cigarette glowing brightly in the airflow in the hand of the driver.

 

[KeepItSimpleStupid]

I don't have to go too far to run into horse drawn carriages. They exist in two different directions from where I live and are very common.

 

[audioguru]

Are you surrounded by Amish people?

 

[KeepItSimpleStupid]

Lancaster PA is close and so is Philadelphia **broken link removed** and I'm in Philly at least a few times a year.

A trip to this place https://www.shady-maple.com/smorgasbord/ offers a free meal on your birthday and I'm likely to run into a buggy or two on the way. It seats something like 1200 people. It's not a type-O; one thousand 200 people.

 

[Tony Stewart]

Hey audioguru, you aren't too far from the Mennonite Apple farms and buggy rides.

When I was young I rode on the horse drawn Milk wagon on our street and later at Victoria Beach cottage we got ice and milk delivered say the same way. Then once a week fresh daily caught Pickerel was sold locally for $1/ lb.. It might be >$3/lb now and $150/plate in Zurich.

With Diodes and switches you can do a lot of logic, Wired AND, OR and Exclusive OR with a diode bridge ... for those uninitiated to DTL.

 

[audioguru]

Hey audioguru, you aren't too far from the Mennonite Apple farms and buggy rides.

I know. I took my dog there and he was scared to death, the first time he saw a horse up close. I think it was also my first time to see a horse up close, but I was brave.

 

[Tony Stewart]

My dog needs turn signals sometimes and a honk mute. But loves horses.

 

[BobW]

One point that doesn't seem to have been mentioned in all of this discussion is that the brake/turn lights are much brighter than the taillight. And the front signal light is also much brighter than the park light. So I don't recommend sharing the park and signal lights.

See the specs for a typical incandescent dual filament light bulb:
https://www.bulbs.com/espec.aspx?ID=13557
3 candlepower for the taillight or park light and 32 candlepower for the brake/signal light. More than a factor of ten difference.

 

[audioguru]

Two candles (or a 2W light bulb) are not much brighter than 1 candle (or a 1W light bulb). 10 times the power appears to look twice as bright.

It is the same with sound. Double the power sounds only a little louder. 10 times the power sounds twice as loud.

 

[Tony Stewart]

Two candles (or a 2W light bulb) are not much brighter than 1 candle (or a 1W light bulb). 10 times the power appears to look twice as bright.

It is the same with sound. Double the power sounds only a little louder. 10 times the power sounds twice as loud.

If light or sound power is radiated from a Lambertian 160 deg range and the listener or viewer only occupies < 0.1 deg aperture of this radiated power then this is how physics works above.

But brightness is not rated in power, it is rated in millicandella which is a combination of the angle and power radiated.

In this case brightness at half current is half millicandella.

But acuity of spot sources diminishes with size and eye resolution at a distance, thus LED sources are diffused or reflected off mirrors to create a larger spot size to improve this long distance acuity. ( also why we dont use laser diodes in brake lights)

10 Candella is very bright with a narrow angle of 30 deg. but lens covers can attenuate at least 50%.
It would also be dangerous for long periods at arms length.
1 Candella is not very bright for brake lights but adequate for large area tail lights
100 Candella is blinding at car lengths.

There are of course details DOT etc stds for new vehicle tail lights

 

[3Ds]

Thanks for all the input and help. I ended up altering a design I found elsewhere that was intended to run trailer lights. The final circuit is below.

Here is the picture of the final outcome. 1 is showing park and the other is brake/signal

 

[shokjok]

This just may be the circuit you need. This is my bicycle trailer taillight interface circuit, a logic "OR" demonstrator, and bike trailer that contains it.
It has been in my trailer since day 1 ( April 4, 1987), and has worked flawlessly since. The PCB is designed around the PC-mounted relays. The 'reverse' circuit is optional, included for my Grote taillights.
I didn't use the larger Bosch relays or a steering column switch assembly then. You can adapt this circuit for 6V positive ground.
In my jurisdiction, horse-drawn wagons and carriages need safety triangles at the rear wall or frame. This trailer will eventually get one, after a major overhaul.