I'm looking for a relay to work with my strobe project.
It seems there are tons of various types out there.
I'd like to be able to buy it at radio shack, but if not i can order online.
From the help received from you guys, I have finalized my project plans.
Next step will be to built each lighting module
I'm just needing a workable relay solution.
for those of you following my progress on this, i've made a few changes, when my led's arrived, they were MORE than bright enough to reduce the size of the arrays.
now its more simple.
below is a picture of my device in the planning stage.
That is a strange non-standard way to draw a relay. SPST relays have four terminals, two for the coil and two for the normally open contacts. I see no reason you couldn't use SPST contacts, but relay do come in SPDT(three contact pins) and DPDT (six contact pins) contact arrangment. The question I would ask before suggesting a on-line source (RS is overpriced and lower quality IMHO) is know how much current each switched LED module will be drawing, as relays are specified by coil voltage and contact voltage and current ratings.
[edit]PS: I hope your symbol -<=>- represents a resistor as one is required for each led series string. It would be a big help if you would learn to use the standard electronic schematic symbols in the future, thanks.[/edit]Lefty
You need to specify exactly what you're doing. Provide your code and show how you plan on wiring it. I can't see where you know how to wire a relay for use with an arduino or other digital output.
I'm sorry its not the corrent symbols, it was drawn up in notepad.
?each 1 ohm resistor dissipates 0.4 mW
?together, all resistors dissipate 0.8 mW
?together, the diodes dissipate 480 mW
?total power dissipated by the array is 480.8 mW
?the array draws current of 40 mA from the source.
+12 volt power source
3v forward voltage
20 forward current (mA
8 LED series/parallel array
being switched ON and OFF at the same time from the arduino pin.
someone tells me a relay is needed as the LED'S are powered by 12 volt, and that can NOT be supplied by the arduino.
I know everyone has different ways of doing this, i'm just looking for the fastest, most simple option
hell, i'll efven use a car horn relay if that would be quickest.
my project is simply 10 strobing led arrays powered by 12 volts in a car.
the code just tells the pins to go high low, high low, high low flash flash flash flash etc.
each pin will be turned on and off quickly.
so i need the led array containing 8 led's to light when told, but they are powered by 12 volt.
i fail to see how the code will help justify what hardware is used here.
ok, so if we take my little notepad diagram here
and replace the relay with a transistor, they appear to be 3 pin, so is it basicaly, +12 on one transistor pin, arduino digital pin on one transistor pin, and led array on the thirdtransistor pin
What transistor would you suggest the "ratshack" sells.
i'm ready to start building this thing, and have successfuly powered my arrays from a computer power supply, so i know they work when powered.
Thank you, an exact answer AND Solution to my question.
Out of all of the replies i get on these forums, it seems you always provide the most useful information.
the whole "rush" is i have a lot of work to do with molding, and casting plastic parts to house all this crap inside, and i need to know how big each array assembled will be.
You have helped a ton.
Like i've said in previous posts, I could just go out and spend a ton of money on a finished product, but where is the satisfaction of knowing you did it yourself.
Thanks
so the Vehicle +12v also connects to VIN?
and the Vehicle ground also connects to GND on the arduino?
That is correct. Again the total current being drawn for all the led arrays combined needs to be known, so the proper transistor and it's base resistor can be properly specified.
?each 1 ohm resistor dissipates 0.4 mW
?together, all resistors dissipate 0.8 mW
?together, the diodes dissipate 480 mW
?total power dissipated by the array is 480.8 mW
?the array draws current of 40 mA from the source.
+12 volt power source
3v forward voltage
20 forward current (mA
Using that information can YOU calculate the total current demand with all the arrays wired up to the single transistor? That is required to select the proper transistor and base resistor. Will it be two modules wired to each transistor for a total current demand of 80ma for each transistor used?
each array will use its own transistor, as each array will be controlled by a single arduino pin, with 10 pins, 10 arrays total.
here are a couple pictures of the breadboard with and without the reflector I have already molded and cast then painted.
so picture 10 of these units, each next to each other, and each plugged into the arduino pins 20 - 29
this way the arduino can control the flash pattern for each array by what pin it is on.
hope that makes sense.
anyways, here is the pictures.
as you see it, it is simply receiving its +12 volt power and is lit full on.
once the transistor is added to the circuit, I will hook it into the arduino, this i have to go buy, and radio shack is closed until Monday.
I know by the design it looks like this is two modules/arrays, but it is one single unit with 4 led's on each reflector to increase the spread of brightness.
as of 5:30pm est, I have a single successful prototype running +12volts, flashing from arduino using a c945 transistor i pulled from a very old computer power supply.
