I found a highly effective deterrent for tailgaters.

A few years back, our local Vietnam War Museum was participating in a parade; but we had to convoy for 20 miles to get to the parade route.

We took our PBR (Patrol Boat, Riverine) with us (the US Navy used PBR's in Vietnam):

I rode in the back of the boat. Enroute, some clown got RIGHT on my tail, so I swung this around and pointed it right at his head:

That's a Browning M2 .50 caliber machine gun. (no, that's not me; it's a mannequin.)

He hit the brakes so hard that he locked up all 4 wheels, and smoke came from his tires. Wouldn't be surprised if he'd soiled his shorts.

 

He hit the brakes so hard that he locked up all 4 wheels, and smoke came from his tires. Wouldn't be surprised if he'd soiled his shorts.

...I would have loved to see that..

 

It was extraordinarily satisfying.

I LMAO'ed.

 

LMAOF....

HAHAHAHHA!!!

I wet my pants I think...
u did not do that???????????????? Did u ?????????

 

Sgt Wookie when he's not driving a boat on public roadways.

 

How did you do that?

 

LMAOF....

HAHAHAHHA!!!

I wet my pants I think...
u did not do that???????????????? Did u ?????????

Yes, I ABSOLUTELY did, and I LOVED doing it!

The Browning M2 machine gun was de-mil'ed (demilitarized) which means that it was incapable of firing even a single round of ammunition, and all of the "ammunition" on board was also de-mil'ed and incapable of being fired, even from a non-de-mil'ed firearm - but my "victim" had no way of knowing that.

From his point of view, he was following a boat too closely, and someone in a military uniform pointed a REALLY BIG GUN at his head.

I really don't care if he shart his pants or not, but from his braking reaction, I'll bet he did. I enjoyed the experience immensely, and hope to repeat it in the future; albeit via more subversive and shocking means.

Beware:
Do NOT tailgate, or you may very well wind up as one of my victims!

 

How did you do that?

Do you mean the video? It's an animated .GIF file.

There are quite a few tools that you can use to create such things. It depends on what you want to use for the source of the video animation.

 

How did you do that?

I used a 555 and some HHO

 

Well, I spent a good amount of time slicing, grinding and splicing the LED ring to make it fit just right. I have mounted it to the jet and can move on now to other things to get it ready for flight. However, I'm really thinking about using the ring with only a speed controller. Going back full circle to where I started.

Here is where I need help. The ring it divided in 4 section of 7 LEDs each for a total of 28 LEDs. I want to test using that ring with a speed controller that will supply between 0 to 12.6v. There are only 2 wires going to the LED so I can only use 1 resistor for the entire ring.

Would I be safe using a single 270 ohm resistor and is a 1/4 watt resistor fine for the ring?

 

I tried and it was dim and didn't flicker. I went down to a 200 ohm resistor and still quite a bit dimmer than when using the circuit that came with the ring. Keep trying lower resistors?

 

What was the circuit that came with the ring?

Can you post a photo of it?

 

What voltage was the ring and its driving electronics made for?

Assuming that each LED has a forward voltage of 2.2V and there are seven in parallel then a 200 ohm resistor from 12.6V results in a steady (not flickering) total current of 52mA and only about 7.4mA in each LED.

Can't the speed controller drive the original LED electronic driver with the original four groups of paralleled LEDs in series?

 

I'm thinking that the original circuit had an inductor with a switch controlling the current through it, possibly operating in a discontinuous mode to keep the LED's reasonably cool and to make variations in the Vf's less significant.

I'll also make a wild guess that the typical Vf's of these orange LEDs will be closer to 2.7v. In that case, our OP would probably have to use something closer to 10-13 Ohms to get 20mA through each LED.

 

What was the circuit that came with the ring?

Can you post a photo of it?

The circuit also drives a set of navigation lights that you can turn on and off with the radio. Two of the navigation lights strobe, alternating between the two. Kind of a funky looking strobe. The strobe is too slow and kind of a flash that dims. I wish I knew more to know what to change on the circuit board to either make the flash faster or make them solid.

For now I don't plan to use anything but the LED ring to keep it simple and keep weight down.

What voltage was the ring and its driving electronics made for?

Assuming that each LED has a forward voltage of 2.2V and there are seven in parallel then a 200 ohm resistor from 12.6V results in a steady (not flickering) total current of 52mA and only about 7.4mA in each LED.

Can't the speed controller drive the original LED electronic driver with the original four groups of paralleled LEDs in series?

Two battery connectors came with the LED afterburner kit. One cable designed for the 4 cell battery (16.8v) has a large 38 ohm resistor in it. The cable for use with 3 cell packs (12.6v) has a large 16 ohm resistor in it.

I have various small speed controllers good for 5 amps and up. So they should have plenty of power to drive the ring. I just want to be careful not to damage the LEDs as it was a bit of a pain to trim the ring down to size. I'm learning as I go along here but I am still an LED newbie.

 

OK, well you have your resistor value; 16 Ohms for use with a 12.6v battery. I wasn't too far off.

So, let's say the LEDs are rated for 20mA. That's a total current flow of 140mA; since you have seven in parallel x 4 series groups. 140mA x 16 Ohms = 2.24V. (12.6v-2.24v)/4 = 2.59 for the typical forward voltage.

Let's check that against the 38 Ohms at 16.8V.
16.8-(4*2.59) = 6.44v; 6.44/38 = 169mA; /7=24.2mA . Seems to be off from what I was thinking earlier.

If the typical Vf was 2.39 and they wanted 27.3mA current through the LEDs, then the two values of resistors would work.
The total drop across the LED array would then be 9.56v. 12.6-9.56 = 3.04v, 3.04/16 Ohms = 190mA; .190/7 = ~27.1mA per LED.

You could verify it by wiring your LEDs in series with a 16 Ohm resistor, applying 12.6v across it, and measuring the voltage drop across the LED strings, or just across the resistor.

The brightness of LEDs is controlled by current, not voltage. If the output from your controller is PWM, then that would work great as long as you have the correct resistor in place to limit maximum continuous LED current. If it's a voltage level instead, you will need to convert that to PWM. It's not too difficult to do using a couple of comparator channels and a power MOSFET.

As far as your existing circuit board that flashes too slowly; we're going to need a lot more details to go with the photo; like part numbers of the transistors that are shown, resistance values, part numbers for the trim pots on the left (are their functions described in the documentation that came with it?) and part numbers on the diodes - along with the functions of the connections on the right side. Basically, we'll need to replicate the circuit in a SPICE simulator.

 

Are the LEDs tiny low current surface mount, bigger 3mm or normal size 5mm?
I would guess that normal-size LEDs operate at 20mA or 25mA for full continuous brightness. Then seven LEDs in parallel use 140mA or 175mA. We can calculate how much is the voltage dropped in the large resistors but we don't know how much voltage loss there is in the "flickering" circuit.

 

Well, the 5mm amber LEDs arrived. I replicated the ring pattern on an "experimenter socket board" to see how they looked. They flickered like the ring in the kit, and were fairly bright, but they are not bright enough to use. I guess the kit must have some very, very, bright LEDs as the few others I have tried don't come close in brightness.

 

Take a look through http://www.mouser.com and drill down through the menus for amber LEDs (or similar color descriptions) and set the typical mCd output filter to include just the really high end devices.

DO NOT give it more info than it needs, sometimes selecting filters like "High Brightness" can eliminate a good candidate as that term wasn't included when they set up the database.

 

I looked through there at the amber / orange LEDs and don't think there is much brighter unless we get into the more exotic high power LEDs. Of the standard 5mm I did find a 25,000 mcd LED but the viewing angle was only 4 degrees so I doubt it would work as you have to look directly at it to see it. The ones I have now are 10,000 mcd but with a very wide 120 degree viewing area.

On the plus side I just tested the motor on the jet and it is producing 23oz of thrust and the plane weighs 22 oz. So with a 1:1 thrust to weight ratio is should fly pretty well.

I built another jet (F-18) from scratch a couple years ago. It didn't fly very fast and was underpowered. It appears I don't have a large enough intake area on it. I may open up some cheater holes on the F-18 now that I have all my gear out working on the F-16. It has survived 2 major crashes a couple smaller crashes so she looks a bit beat up. The crashes were electrical and radio problem related.

I printed up some stickers for the F-16 and I'm getting pretty close to wrapping it up. Needs a little paint and to secure and mount the electronics. Here are my ducted fan foamy jets...

This is what it looks like if you use the stickers they supply with the kit. I didn't like that look at all.