Remotely Controlled outlets.... Thoughts
I've been toying with the idea of building a 120v power strip that can be controlled with a computer. I've done this before, using the Parallel port to control some solid state relays which power on or off an outlet.
But I want a newer, fresher, better version - Using the Parallel port has given me problems - I don't have one on my laptop, and some of the newer computers that I've used only output 3.2vDC, and my old design seems to need 5v.
Here are some of my ideas -
Use a metal 6 outlet strip to house the project - something like this: http://www.shoplet.com/office/db/g9664.html
Use the same solid state relay design as my old one:
A Triac: http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?jameco_pa...
Optoisolator: http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1...
A few resistors
Here's the schematic: (thanks to http://drew.hickmans.net/switching_110VAC.htm)
Use a LED Driver to control the Optoisolators. Problem is, I don't exactly know how they work... But I'm sure I can found out somewhere..... ;-)
http://www.arduino.cc/en/Tutorial/LEDDriver
Of course, use my Arduino to test drive it - http://www.arduino.cc/
Many, many thanks to Keith Neufeld for giving me one!
But in actual production use, I want to control it with a X-port - http://www.lantronix.com/device-networking/embedded-device-servers/xport...
Create a web-based interface - Accessible anywhere in the world!
It'd be nice to cram a 3.3Vdc transformer inside of the power strip to power the Xport and other circuity.
I've drawn up a few schematics, but still have a lot to learn. I'd also love to make a PCB for the project.
Still got a few questions that need to be answered - Which I'm working on:
1. How many Amps can an appliance pull from my current SSR?
2. How exactly does a Triac work (a bit fuzzy)
3. How does a LED Driver work? (clueless)
4. Serial Communication? I haven't messed much with my Arduino, I have to admit :(
5. PCB creation? I've downloaded gEDA editor - I know EAGLE is popular too - But I don't really know how to work either!
More to come....
| Attachment | Size |
|---|---|
| oldoutletbox.pdf | 1.65 MB |
| SSR2.gif | 2.43 KB |
Comments
I always enjoyed
I always enjoyed transformers before, well...Mr Bay...
Re: Triacs Yeah, I've looked
Re: Triacs Yeah, I've looked into the pre-packaged ones. They are a bit bigger, of course, but I think they pay off it I can plug bigger items into the outlet.
Re: LED Driver
Right, I knew the Arduino could drive it, but the end result would not include the Arudino, so I'm looking for something to interface the XPort and the Relays.
I'll have more questions... I'll just ask in person.
Okay, here we go. Triacs:
Okay, here we go.
Triacs: I'd suggest maybe using prepackaged solid-state relays instead of triacs. I think they typically have a higher current capacity because they're enclosed in a giant heatsink, I think there's a fair chance they'll already be optoisolated, and there's typically more distance between input and output pins so you don't have to be as paranoid about short circuits.
I have a box of solid-state relays. Pending further agreement, I propose to trade me supplying six relays, circuit board materials, and design and manufacturing assistance for you looking up a datasheet to determine whether the relays are optoisolated; and after successfully building your own networked power strip, building me one too using materials I supply.
LED driver: Not needed, if you're looking for fewer than about thirteen relays per unit. The Arduino has about thirteen digital I/O pins that can drive LEDs (including optoisolators) directly, so you don't need to play tricks with port expansion. Even taking out pins for Arduino-XPort communication, you should still have plenty for a six-outlet strip.
Arduino / XPort: My impression is that the XPort doesn't have pins to control LEDs directly, but rather uses (TTL-level) serial communication with a microcontroller to let the microcontroller do the I/O work. The Arduino would make a good development platform, and a custom board could be designed with the Arduino's ATmega processor and an XPort, rather than sticking a whole Arduino and XPort shield into the case.
PCB software: I use EAGLE, it's very common in the hobbyist world, it's free of charge for noncommercial projects, and it'll work up to about 3" x 4" boards. I'm also interested in learning more about gEDA -- I'd be happy to watch / help you work with it.
I expect that doesn't fully answer all your questions, but maybe it's enough to get you going.
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