DIY Sequential Taillights for approx $20

[12camlt]

Just FYI, I would be interested in a kit if one comes together. Looking for what exactly I need at my RadioShack isn't my cup of tea.

[gutterball]

hapisok, The 555 timer doesn't have enough drive to power the Relays, instead use the 555 to drive the transistor, and have that turn on the Relay.

[sjmautoprod]

Well, a 30mA-coil relay is a game-changer.

[Jason@JacFab]

I would pull the trigger on a solder-it-yourself kit if the price was right...

[sene]

Originally Posted by sjmautoprod

Checked with whitedemon, and, I'm wondering if there is interest in kits for these. I'm thinking just the parts and a board for people to build up on their own.

I'm in for something that is ready to go.

[SmokeScreen45th]

+1

[wadew2lt]

Subscribed!
Nice write up.

[carrs_crew]

+1

[67ss350camaro]

Ok, I looked at what was done so far and found some problems with it. The main problem with automotive is that temp and voltage rages are important. I assume that these are going to be installed right next to the tail lights. This area is open to all of the elements. I would say the board needs to be put into a sealed box or potted. Looks like the reason that the 555 burned up is because the relay that was used drew to much current. I bet that at 12V it drew ~166 mA, but when the voltage got to 16V, it would then draw 225 mA. So a higher coil resistance is needed.
Here are the parts I think need to be changed.
All part numbers I am giving are digikey part numbers.
555 timer - 296-9684-5-ND.
Relay - 255-2223-ND.
I think these two changes would fix the problem with the units electrical problems, but again, this needs to be sealed up to withstand the weather.

[pkauf]

Originally Posted by 67ss350camaro

Ok, I looked at what was done so far and found some problems with it. The main problem with automotive is that temp and voltage rages are important. I assume that these are going to be installed right next to the tail lights. This area is open to all of the elements. I would say the board needs to be put into a sealed box or potted. Looks like the reason that the 555 burned up is because the relay that was used drew to much current. I bet that at 12V it drew ~166 mA, but when the voltage got to 16V, it would then draw 225 mA. So a higher coil resistance is needed.
Here are the parts I think need to be changed.
All part numbers I am giving are digikey part numbers.
555 timer - 296-9684-5-ND.
Relay - 255-2223-ND.
I think these two changes would fix the problem with the units electrical problems, but again, this needs to be sealed up to withstand the weather.

What do you mean by "potted" - i get using a project box and sealing it to the elements, but don't know the term . . .

[pkauf]

Originally Posted by pkauf

What do you mean by "potted" - i get using a project box and sealing it to the elements, but don't know the term . . .

Never mind, looked it up. Something like this? http://hackaday.com/2012/06/04/potti...with-silicone/

[67ss350camaro]

Originally Posted by pkauf

Never mind, looked it up. Something like this? http://hackaday.com/2012/06/04/potti...with-silicone/

Yes, but usually epoxy is used, but I guess silicone would work also.

[pkauf]

Originally Posted by 67ss350camaro

Yes, but usually epoxy is used, but I guess silicone would work also.

Cool, i'm sure there is stuff about that also - i just meant the general idea.

Thanks!!

Paul

[whitedemon]

ok peeps.... we tried 2 nights in a row for hours trying to make the transistor circuit we built work. It would either not fire or when we got it to fire the bulb it would over heat or over heat the timer. We went back to the basic relay circuit that worked and did some research. come to find out radio shack sells a tlc555 timer which is low power and a high power timer which is the one rated at 200 ma. We crunched some numbers and found even at 15v the relay only draws like 160 ma. So after re inspecting the original circuit we found that we accidently bought lower power timers the first time and thats why they burned up. Last night I installed the high power 200 ma timer in the original circuit and ran the brake lights for 1-2 min solid and blinkers for 3-4 mins, then checked my circuit and found no heat on the timer or components. I think its going to work now so im going today to buy another high power timer and hook up the right side again and I will test it out this weekend and ill post results monday. Yes relays are not as nice and quiet as transistors and mosfets but they are a hell of alot easier to work with lol.