Using the picocompressor GR meter as Knight-Rider lights...

So Amorris and I are looking to "pimp ze auto" here at work. (an electric delivery truck, which the bosses were foolish enough to christen "Kitt"... we're intent on making them regret that flippant course of action!)

Anyhow, what I want to build is one of them red-light ramps that slowly 'swishes' from side-to-side. -I can use LED clusters or 12V lights, but -looking at the 'Knight Rider' clips on youtube, there's a definite "afterglow" that fades down, "smoothing" the switching from bulb-to-bulb.

I was thinking of an up/down CMOS counter, but I don't see a simple way... My second plan is a bargraph driver in "dot" mode, with it's output feeding lamp drivers that have "slugging" capacitors to help with the gradual fadeout of the lights... If I fed a slow triangle wave in, it should do the "Swish" think pretty well, I think...

Anyone know of any easier solutions?

Keith

well not really "easier" but you could always do it digitally.. outputs PWM ramps to Nfets..

it would be many fewer parts but more work in the code domain.

my 67 cougar has sequential taillights... switch fingers actuated by a rotating cam driven by a motor..

Digital counter into deMUX into sluggish lamp driver should work fine. 16 segments means two deMUX (I don't know of any TTL or CMOS MSI parts that are more than 8-bits wide). 32 would require four. 74xx138.

You could also go with a shift register arrangement with some external logic for startup and a couple of toggle F/F for reversing the direction at each end. Of course you'll need a clock, too.

Pretty simple stuff...should be a fun project. We'll need to see video when it's done, of course. :grin:

A P

How many lights?

If 8

Maybe a 3 to 8 decoder chip driving some transistors then light bulbs with a octal count up count down. CMOS or TTL

Or go to dot mode with a liner bargraph and feed it a triangle wave

The Knight 1000 also had that sound that accompanied the lights. You have got to have the sound. I like the old beer signs that had a sheet of plastic rotating in front of a light, looks like a waterfall. something like that might work.

(sigh)

Too much unfamiliarity for me to do the digital thing...

I'm all analog! :wink:

Definately need the sound too!! Otherwise, you're just playin'

Light-sweeper, no afterglow (which may just be film/video artifacting), no sound, but only 24 GB-bucks in kit form:

http://www.quasarelectronics.com/1088.htm
http://www.electronic-kits-and-projects.com/kit-files/1000/1088.pdf

> a definite "afterglow"

6-phase 0.5Hz tri-wave oscillator, 400Hz triwave, six comparators. (On 'scope this gives fore-glow too; I suspect on incandescent the afterglow will dominate.)

Sell that silly 1908-technology delivery truck. For what a truck costs, you can buy a well broken-in 1984 'Bird converted to "T-top" with KITT lights and instrument panel "in progress", halfway down this page:

http://www.markscustomkits.com/For-Sale.html

The '84 Bird has a vast cargo space if only one person need fit. (Yeah, many mini-SUVs have more space in 5 feet less length, but everybody and his daughter has one.)

My Mom had one of this-series Birds when new. Good car. With the teeny V-6, it was entirely adequate for my mom: even merging onto the freeway she never took it past 2,500RPM. One day at grandma's I took it out alone "to get milk", got several blocks away out on the main drag of Columbia Missouri, and booted it. That cut-down motor screams, hauls hinnie up to 5,000RPM. My 302 Cougar was faster, but not by much. With a 350 V-8, these Birds must have been kid-killers.

They seem to hold up OK for pony cars. Rust never sleeps, but 1980s were better than '60s and '70s cars. The Camaro/Bird used the Monza torque beam: the rubber sandwich under the tranny DOES need replacement. The doors are longer than some cars and do sag. Most other parts are robust. The engines are semi-available second-hand, and you can buy a new-in-crate GM 350 engine that is 95% bolt-up and more power with lower smog. Any GM smallblock should pretty-near drop-in, perhaps with a tranny and new mounts. That includes some mighty Corvette mills. The big-block 454/502 might "fit", though you need sturdier gears and you better aim good before you step on the gas.

A LM 3914/15 meter chip driven by a slow triangle from a 555 sounds good.
That's as analog as you can get.

Thats the Bunny!

larrchild said:

A LM 3914/15 meter chip driven by a slow triangle from a 555 sounds good.
That's as analog as you can get.

Click to expand...

yeah, there's actually a bit in the datasheet for the LM391x series that talks about modulating your "DC" input with an oscillator to get the apparently more "smooth" transition from one dot to the next. however, i think the kitt effect only had trailing "afterglow"... maybe you could do that with a ramp osc, but it would have to change directions with the dot travel direction. there has to be a simpler way.

ed

I've seen a kitt-kit somewhere. A pre-programmed PIC and a PCB for a couple of $$. I think digital is the easiest way to do this. But analog would be nicer. Let's make this the next group diy project. Forget about audio.

/Anders

http://www.quasarelectronics.com/1088.htm

http://www.oz.net/~coilgun/kitt_car/home.htm

Awesome stuff.

I think I even have all of those parts at work. -This might even be built and installed by 5PM...

Iactually thought about a 4017 decade counter, but I never thought about couble-connecting the middle pins to make it "reverse"... -Clever.

Keith

Keith,

You could try/buy a 12V PLC with transistor outputs and program it to your liking.

A very quick and easy solution but maybe not the cheapest.

We use Telemecanique here at work a lot, theyre good and reliable.

I have installed and programmed one for controlling a pneumatic gearbox in a 1000hp racing car. Worked like a charm.

what did I post? I guess it was not read to the bottom.

Just make sure you have a radar detector, too; friend of mine stuck some red lights in his grille, and we got pulled over by the fuzz, and he got a ticket, 'cuz red/blue lights are reserved for emergency vehicles only, at least in this neck of the woods. Not that you could mistake his car for an emergency vehicle; it was an 87 red Cougar. The cop must've thought we were trying to be Starsky & Hutch, or something! :grin:

Hang a capacitor on the base of the lamp drivers or do that and use a Darlington if the decay isn't slow enough.

I thought about the cap before the resistor... Looks like the 4017 doesn't mind 'back-voltage' into a low output pin, since that's how they've done the shared lights on the 'ring'... 6&4, 7&3, 8&2, 9&1 etc.... with 0 and 5 at each end alone.

that way the cap decays through a resistor, rather than a sharp turnoff junction... Maybe add a switching tranny to handle the inrush load as the cap charges though... -CMOS isn't known for high-current delivery. :wink:

Keith

Use a steering diode, and make it a darlington to raise Rb.