iamsuperbleeder
New Member
Hello everyone!
I'm just getting into circuit designing and PCB layout and construction. That said, I've been doing my homework, but still would like a little input on my project![Big Grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I'm working on adding additional LEDs on the side mirrors of my truck, that will act as running lights and turn signals. Originally I was just going to use a very simple circuit with resisters and diodes and make the LED's light dimly with the running lights, and full brightness with the turn signals. However, I've been looking at another option which, if done right, will make them be lit at full brightness with the running lights on, and then when the turn signals flash when the running lights are on, the LEDs will flash in an alternating pattern that the turn signals on the truck do. When the running lights are NOT on, they will simply flash at full brightness along with the turn signals on the truck.
It's kind of hard to explain, so I made a simple animation that does exactly what I want to circuit to do:
**broken link removed**
Using a logic gate simulator, I was able to get this to work perfectly, using XOR gates. So upon research, I've found the 7486 IC is what I can use in my circuit for the XOR gates (only two gates are needed in my current design).
The logic part of the circuit and the 7486 IC isn't what's getting to me; it's the unput voltages that I'm concerned about.
Obviously a vehicle's voltage is suppose to be 12v, but while running, a vehicle can be at 14.5v normally, and the supply is very unstable as far as fluctuations go (just because of the nature of the alternators vehicles use to keep the battery charged).
I know I'm going to have to use some 5v regulators like some 7805's, as well as some caps to take the fluctuations out, before sending ANY power to the IC. What makes this a pain is that I'll have to have 4 separate 5v regulator circuits for just the inputs; 1) constant supply, 2) running lights, 3) left turn signal, 4) right turn signal. Is there an easier way to go about doing this aside from using 4 regulators and 8 caps? All of those components are going to take up quite a bit of space on a PCB, and I'm hoping to keep the package as small as possible so that I can wire it in and just velcro it up under the dash some where.
My second question would be, what would be the best way to, after I drop the voltage down to 5v for the circuit, bring the voltage back up to 12v for the two outputs? Just a couple of transistors to use as a switch, with a 12v feed in, the 5v output from the IC as the trigger, and the output as, well, the output? That's the only logical solution I can think of.
I wish it could only be as simple as being able to run the full 12v through the IC, but life's never that easy![Stick Out Tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I'm home-making this PCB, so it's just going to be a single layer PCB. I just placed an order with Jameco for a bunch of stuff to get me started (breadboard, organization box, grab bag of resistors and LEDs, a few 7486 IC's, a hand-full 7805's, and some other misc things), and I'm just picking up some standard pre-drilled PCB's and a project box from Radio Shack.
I'm using ExpressPCB to try and get a basic layout done right now, and can post a screen shot up of the layout once I think it's done. But I'm open to any suggestions or input as far as schematics or PCB layouts go. It is a pretty simple circuit, I'm just an electronics nuB for the most part
as far as PCBs go anyhow...
Thanks in advance!
I'm just getting into circuit designing and PCB layout and construction. That said, I've been doing my homework, but still would like a little input on my project
I'm working on adding additional LEDs on the side mirrors of my truck, that will act as running lights and turn signals. Originally I was just going to use a very simple circuit with resisters and diodes and make the LED's light dimly with the running lights, and full brightness with the turn signals. However, I've been looking at another option which, if done right, will make them be lit at full brightness with the running lights on, and then when the turn signals flash when the running lights are on, the LEDs will flash in an alternating pattern that the turn signals on the truck do. When the running lights are NOT on, they will simply flash at full brightness along with the turn signals on the truck.
It's kind of hard to explain, so I made a simple animation that does exactly what I want to circuit to do:
**broken link removed**
Using a logic gate simulator, I was able to get this to work perfectly, using XOR gates. So upon research, I've found the 7486 IC is what I can use in my circuit for the XOR gates (only two gates are needed in my current design).
The logic part of the circuit and the 7486 IC isn't what's getting to me; it's the unput voltages that I'm concerned about.
Obviously a vehicle's voltage is suppose to be 12v, but while running, a vehicle can be at 14.5v normally, and the supply is very unstable as far as fluctuations go (just because of the nature of the alternators vehicles use to keep the battery charged).
I know I'm going to have to use some 5v regulators like some 7805's, as well as some caps to take the fluctuations out, before sending ANY power to the IC. What makes this a pain is that I'll have to have 4 separate 5v regulator circuits for just the inputs; 1) constant supply, 2) running lights, 3) left turn signal, 4) right turn signal. Is there an easier way to go about doing this aside from using 4 regulators and 8 caps? All of those components are going to take up quite a bit of space on a PCB, and I'm hoping to keep the package as small as possible so that I can wire it in and just velcro it up under the dash some where.
My second question would be, what would be the best way to, after I drop the voltage down to 5v for the circuit, bring the voltage back up to 12v for the two outputs? Just a couple of transistors to use as a switch, with a 12v feed in, the 5v output from the IC as the trigger, and the output as, well, the output? That's the only logical solution I can think of.
I wish it could only be as simple as being able to run the full 12v through the IC, but life's never that easy
I'm home-making this PCB, so it's just going to be a single layer PCB. I just placed an order with Jameco for a bunch of stuff to get me started (breadboard, organization box, grab bag of resistors and LEDs, a few 7486 IC's, a hand-full 7805's, and some other misc things), and I'm just picking up some standard pre-drilled PCB's and a project box from Radio Shack.
I'm using ExpressPCB to try and get a basic layout done right now, and can post a screen shot up of the layout once I think it's done. But I'm open to any suggestions or input as far as schematics or PCB layouts go. It is a pretty simple circuit, I'm just an electronics nuB for the most part
Thanks in advance!