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Light sequencer of sorts help

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New Member
New to the board :lol:

I'm trying to design a light sequencer of sorts. Basically I have one of those old cars that has the sequential taillights. The system they used was mechanical activation for the sequencing of the lights but I want to design something electronic. Basically its 12VDC system, has three lights per side. I need it to turn the inside light on first and stay on, then the second and stay on, then the third and stay on. Then they all stay on for about one second and then the sequence starts again. Anyone have any ideas? I saw sequencers that activate one light at a time but I need something that will hold them on after there activated in sequence. I'm looking for something simple to semi-simple as I don't have a PLC programmer or anything like that to work with.



Well-Known Member
Light sequencer

A CMOS serial shift register would do the trick.

Connect the D input to +12 Volt (when you want the sequence to start)and connect a 1 Hz oscillator to the clock input. Connect a suitable lamp driver to the first three outputs and connect the fourth output to the reset.

Thus the lamps will light one at a time at 1 s intervals, stay on for 1 s and then go out and the sequence will start again.

However, you need to protect the CMOS from voltage spikes on the +12 Volt line. I suggest that you put a 15 Volt Zener across the +12 line and a resistor in series. Also connect a 100 uF and a 100 nF capacitor across the CMOS supply line. These will suppress the spikes and thus protect the CMOS.

You certainly don't need a programmable device for such a simple requirement.

Feel free to send me a PM if you need further help



New Member
light sequencer

:D hi ljcox,

thanx for the reply, i will try the system you suggested. i hope i get it right, in case i will have a problem i beleive you are there to help me out.

i will also try the sebi approach, i already have the device he suggested. :D
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