karel wrote:
"Richard Lamb" schreef in bericht
link.net...

wrote:


well I have a semi truck and a light bar with 12 marker lights in the
bumper I am going to wire them 6 and 6 so when I turn on the turn
signal they flash the right way 6 will flash right and 6 will flash
left I would like to go further and make them flash in a seires
1,2,3,4,5,6, how do I do this. what relays do i need and or anything
eles I would like them to start to flash in the center at number 6 and
flash one at a time down to 1 and work there way to the out side of
the bar so it would be 1,2,3,4,5,6 6,5,4,3,2,1,and start over again.

left side right side


Something with that many options would be easiest done with a micro
processor and a dozen solid state relays.

Bit of overkill, I should think.
And not Jim's approach either.


Otherwise, it's gonna get ugly with a bunch of TTL or CMOS LSI chips.

Ugly? One CD4017 as a counter with the decoder built in,
and a 555 as a free running clock oscillator.
Then for each lamp a mosfet (much more reliable than a relay,
and less expensive than solid state relay) and you're done.
It ought to be feasible to build the circuit only once
and have it drive both sets of lamps.
And oh yeah, will be less perturbed from spikes & the like
if you feed through an 7809 or so rather than straight from the battery.


SCR's won't work for the switching because it's DC powered. Once turned
on, they won't go off until voltage crosses zero.

Yep!


I think we're going to have to call in an expert.

Well I'm not claiming to have Jim's level of expertise.
But that would perhaps be overkill too, for this simple project.

BTW what's it to do with aviation?
Who would want to carry all this flashy extra weight?
Or is it to make sure the truck gets seen on the airfield?
KA


Haven't you heard? FAA is proposing turn signals on aircraft.


Dan, U.S. Air Force, retired