I have discussed a car tail light circuit with chasing features in one of my earlier blogs. The system is able to transform into a full fledged brake light with all the red LEDs lit and also is able to perform the function of chasing turn signal indicator by switching the same sets of LEDs.
Recently some modifications were suggested by one of the interested readers of this blog, let's know more it.
Mr. Jefferson Furtado who is an electronic hobbyists and a keen reader of my articles suggested me some modifications for the above circuit which according to him would make the circuit more efficient with its operations. This is what Mr. Jefferson recommended:
"Just curious why you used the 4060 instead of two 4049s. Was also thinking I could do the same thing with a 556 and used the second timer to pwm the taillights instead of using the resister. What do you think? What are the advantages/disadvantages of the different oscillators?
Also I was thinking of using an inverter on the brake lead and nor gate it with the blinker lead so the blinker overrides the brake. How it is now if you stop at a left turn light, when you hit the brake the blinker effectively turns off. I could also do the same with the dimmed tail lights if they cause a problem with the sequencing. What do you think of this solution?
I'm a complete noob, I really just researched enough to be dangerous so any insights would be greatly appreciated."
The IC 4060 section can be replaced by any suitable oscillator, there's no specific reason behind using the IC4060, any similar oscillator will do.
Your suggestion looks interesting, would be nice if you could provide it in the schematic form."
Jeff = I'm not sure how to add images to a reply, but here are links to my schematic
I think I need to change my schematic so that I'm running the ICs from a 5 volt regulator and use the 12 volt regulator to run the LEDs to maintain a consistent brightness level. Can I piggy back the 7812 to increase the AMP capabilities or should I just use one 7812 for the left and another 7812 for the right?
My analysis about the above circuits:
The first circuit looks perfect to me, the second circuit concept is also OK, however the transistors are wrongly configured.
Correction= The transistors are NPN types, so all the diodes and the LEDs in line should be reversed, the resistors common point goes to the positive instead of negative as wrongly shown in the diagram
Thanks Jeff, that was indeed a great effort, appreciate it.
The 7812 IC need not be enhanced because it has sufficient current for driving all the connected LEDs.