Guys, I'm getting a headache here. I have about 10 relays I need to wire up and control with an Arduino, and I can't even get started here. I've been limiting myself to 5v relays, but I'm having a hard time even finding something as simple as a 10a/5v/SPST or DPST relay. Even when I do, I'm getting conflicting info about how to use it. It makes sense I can just wire it to the digital pins on the Arduino, but this schematic says otherwise:
But I can't tell WHAT the hell it's telling me to do! There's this unknown device, K1, in the schematic (next to the diode), that serves a mystery purpose. I can't tell what it's telling me to do. Where is the relay getting its power? From the relay's load?
On the high end, I need to drive 3 12v/10A loads. One that controls the direction (DPDT reversing circuit) and one that selects which motor to activate (DPST). On the low end I only need to send a 12v signal to another 12v relay, and I was going to use SPST relays for those.
But I can't find any of the relays I need to use. It's almost like, using that diagram, I could use 12v relays (it references using an "external power source" to power the relay... HOW??).
Really frustrated here with that diagram. IMO someone should clarify the purpose of K1 in that schematic and re-upload it so frustration like this ceases to exist.
Oh for geez. Now that makes sense. The relay should just be a standard relay schematic symbol then...
A coiled wire, that's what I was looking for. I thought the exit points of the schematic ("Relay power V+" and "GND") were to be connected to the relay coil. I was hurting my head trying to figure out where relay power would come from! ;D
That's a very much more appropriate relay control design than I had planned. The voltage fluctuations on my test bench with just a simple buzzer/speaker was causing the RF receiver to glitch out, even with a capacitor along the +/- supply for the receiver. So by driving a transistor, which in turn drives the incoming +12v supply (that will also be used as the load supply for the relays - it's all going in my car), that'll totally solve the voltage fluctuation problem!
Thanks for the help!
edit: As to what's being powered here? I'm using the Arduino to drive various functions on my car from a keychain transmitter, a sort of "arduino car alarm" of sorts (although I don't have the alarm details worked out quite yet). Here's the main topic:
www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1291421706/0#0
The window switches in the car form a hardware H-bridge, something I need to emulate in relays. I've already got those details worked out here:
www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1291073129/0#8
So yeah, I've been hard at work on this. I might be able to eliminate 2... maybe even 4 of those relays by using a transistor instead, though, now that I understand the concept used here to drive 12v relays...
Trying to add a new part to Fritzing is the SINGLE MOST FRUSTRATING THING I HAVE EVER HAD THE DISPLEASURE OF TRYING TO DO. I've spent the better part of the last FOUR HOURS trying to something as stupidly easy as taking specifications from a datasheet and putting them in the damn program. So I have the part design bootsy-designed in Inkscape (another ridiculously frustrating program) and saved as SVG. But will Fritzing work with it? Ohhh, NO. It shows a pretty picture on the screen. Can I assign connectors to it? Noooo. I try to add a pin and it makes a shiny little box in MIDDLE OF THE PART. In middle of nowhere. Can I move that box? Nope. Can I move the pointer? NO. Can I do anything at ALL with its arbitrarily-placed box? Nope. Just a box. Plopped in middle of nowhere. I can do NOTHING with this part.
I have NEVER shouted this loud at my computer, and it's a DAMN good reason I recently swapped out for a solid state drive. And that I restrained myself from smashing my fist through the screen. Because I would have no more computer tonight if I still had a hard drive in there. Damn near ended up throwing it across the room.
Seriously, open-source contributors really need to think about it for a minute and make sure people can actually UNDERSTAND the interfaces they develop.
No, it's just unnecessarily frustrating when a program's like "It's sooo easy to do this! Just do this, this, and this!"... then each "this" consists of about a hundred thousand undocumented steps with no rhyme or reason, while the program essentially just sits back and laughs as you struggle to figure out what's so "EASY" about doing "this".
For example... just try to actually use Inkscape to make a Fritzing part just like the template packs. :
