I have two 12 volt lights that came from an old police car. Does anyone have a simple way to wire the two of them up to make them flash again? Right now I have them wired to individual push button switches, but I would like to make them flash on their own.
Also I have a Police strobe light (Whelen 02-0361112-00) with red, black, and white wires where the white white wire leads through a circuit and to the bulb. Does anyone know how to make this work as well? Do I need some sort of control module or can i just use simple switches and power supply?
Hi PG, there are many ways to mack your 12v lights flash on their own. The circuit colin55 posted will make them alternate left/right. If the lights you have draw alot of current, you may have to modify it a bit.
The strobe light will require a high voltage power supply and a way to trigger the tube to control the flash pattern. Many commercial made strobe light power supplys will take care of both.
Please note that putting flashing lights on cars in not legal in most countrys.
What do you mean by: "there are many ways to make your 12v lights flash ON THEIR OWN." How can globes: "flash ON THEIR OWN?"
What do you mean by: 'If the lights you have draw alot of current, you may have to modify it a bit."
The BD679 darlington transistors deliver 4A with a peak of 7A and this is adequate for the application. We have sold thousands of kits for $5.00 inclung parts and PC board, so I don't know what you are talking about.
He said he was using a seperate push buttons to flash them. Your circuit will makes them flash without having to sit there pushing buttons. By "on thier own", I mean with no human interaction.
He didn't say what kind of pattern he wants. Yours will do single flash left/right. If he wants double or quad flashes, or something else, a differnt circuit will be needed. If he wants both to flash at the same time, or dosn't care about a symetrical pattern, a 12v turn signal flasher or two will do the trick.
He dosn't state exactly what kind of lights these are. They might be little dash lights that draw hardly anything or rooftop lights that draw several amps.
I didn't look up the datasheet for the BD679 before I posted. After reviewing it, I would doubt that his lights draw over 4 amps, but I don't know. From his post, neither do you.
You must make the circuit very "tight" otherwise it will not oscillate. This requires the leads to be thick and the wiring to be as short as possible. This is due to the very high "cold current" of the globes - 6 to 10 times the operating current.
Three 700mA blue LEDs in series with a suitably sized series resistor aught to do it. Because they're driven at 50% duty cycle, you can also drive them at a slightly higher current than their rating to increase their brightness.
This is the type of design I would really like to use. The only problem is I'm not too good with schematics. Is there a parts list for this circuit somewhere?
What did Chuck Norris' flashing headlights look like? I don't remember them from the show. '
I am pretty sure U1 in Boncuk's schematic is a 555 timer. Its very common and easy to get. U2 looks like a 4017 Decade Counter. Also very common and easy to find.
The BUZ10's are power MOSFETs. The resistors and capacitors have values next to them.
The 555 is used in astable mode. If you google "555 astable" you will get lots of pages to learn about how this works and how to adjust the speed.
The 4017 just clicks along at the speed the 555 is going, setting one pin at a time high. Pretty much
Pulse 1 from the 555 sets Q0 high and lights lamp A
pulse 2 will make Q1 go high and Q0 go back low. Nothing is hooked to Q1 so lamp A goes out
pulse 3 makes Q2 high and lamp A goes back on
then we have 2 unused pins that give a delay and then we move over to lamp B and repeat.
Q8 is hooked to the reset pin on the 4017 so we can do it all over again. This just loops over and over and over.
Make sense? The diodes block the current from going back to the low pin on the 4017
The speed of 20Hz seems way to fast for a incadesent bulb to me. I don't think it will even flash at that speed, just look steady and a bit dim.
I am sure Boncuk will stop back in and clarify this in time. He's a regular around here.
Both MOSFETs will stay on because the LEDs (which won't light) prevent the gat capacitance from being discharged when the IC's outputs go low.
It looks a bit too complicated. I'd just use a couple of NANDs connected as an astable driving a pair of MOSFETs via another couple of NANDs acting as a buffer. I'd use a cheap CMOS quad NAND such as the CD4011.
The lights I am using do have incandescent bulbs. I just purchased all the parts yesterday but have not soldered them yet, so if I need to return them I still can.
Yes, I chose the "Chuck Norris" circuit lol. I unfortunately don't have any way of putting it together without soldering. I have to wait until the end of the week to put it together anyways, so I'll just wait to see if anyone can find problems with it.
The LEDs he added in series with the MOSFET's gates prevent their capacitances from discharging.
If the frequency is low enough then this might not matter since the diode leakage current might discharge the capacitance there again it might not so the MOSFETs will never turn completely off.
The LEDs will also never light, well the may light for a couple of µs when it's first started but you woudnn't see that.
I think he forgot that MOSFETs have a high impdance capacitive gat and need a push-pull driver. If the MOSFETs were replaced with BJTs then it should work fine.