question about basic stamp homework board
devin0
Posts: 6
Hello, im new to these forums sorry if i posted this in the wrong place. Im doing a project with my basic stamp homework board that involves 120v ac. If i pass 120v ac through the breadboard in the basic stamp homework board will it damage the breadboard? Im not sure what the maximum voltage is for the breadboard is so i wanted to ask so i don't damage the board by mistake.
Comments
You'd be better off describing what you're trying to do. There may be safer solutions.
http://www.x10.com/automation/x10_pl513.htm
and attach the light to an X-10 module (you can find several on the same web site).
The X-10 controller provides all the necessary isolation so you will not be dealing with dangerous voltages at the stamp. It will also allow you to control multiple devices using your house wiring to communicate from the X-10 controller to the X-10 modules.
Since you're using a homework board, that already has series 220-ohm resistor inline with each IO pin. See sketch attached.·That means you'll only need a 100-ohm·series resistor to·switch on a 2N2222 transistor to supply·the 5V to switch your relay. And you will want to use a flyback protection diode across the 5V relay coil to avoid damaging your stamp.
http://www.radioshack.com/product/index.jsp?productId=2062480· is the smallest relay you should consider, since that's only good for 1 amp at 125 volts, or 125 watts.
To be a resposible Forumite, let me repeat: If you don't know what you are doing, you can get zapped. Don't drink & drive. Stay in school. Buy low, sell high.·Always use·Parallax.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·"If you build it, they will come."
Post Edited (erco) : 12/31/2008 6:08:51 PM GMT
Due to the EXTREME DANGERS of working with 110VAC house current, I would only recommend a solution such as the X10 if you are trying to design systems that switch and manipulate 110VAC. The system provides all the necessary isolation for the basic stamp and is nicely supported within PBasic. The Professional Development Board even provides the RJ11 interface for the X-10 module. The system gives you all the control necessary to operate lights and appliances and can be nicely driven by a BS2. I'm currently using X-10 to control the room lights, the flood lights and the model lights on my model railroad and I don't have to worry about the 110VAC power. I fell the $120 I invested in the X-10 controller and modules was the best form of life insurance I could purchase.
Reading through these forums, the XOUT command seams to be one of the most underutilized features of the BS2, yet it provides the safest means of controlling 110VAC that is currently available to experimenters. I hightly recommend reading
http://www.parallax.com/Portals/0/Downloads/docs/prod/stamps/BS2Appnotesv1_9.pdf
Post Edited (MSDTech) : 1/1/2009 4:18:52 AM GMT
just came across this post and it almost exactly what I have been trying to work on.
I have the Firecracker, the Basic Stamp 2 Homework Board, and my "button" to turn everything on. I want to make it so that my firecracker sends a signal to my X10 computer interface, which is plugged into my computer, to then forward the signal to my modules, spacing each signal to each module in 2-3 second intervals. My main concern is how to wire the firecracker, so the board, so that when the button is pressed it send my signal to my computer, which runs a script (created from a program perhaps?), which will send out the signal to my modules. any help?
http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=119
I built that device, following the tutorial instructions carefully, and it works. It was my first foray into controlling 120VAC, though I also have a Futurlec Optoisolation board with 4 relays that can handle house current (I've only used it with 12VDC so far).
I'm skittish enough about wiring that I wouldn't think about leaving either of those devices plugged in while I wasn't actively working with it. They're fine, I think, for experimenting, but I wouldn't think of anything I wired together like that as a replacement for a commercial product for controlling house current fulltime/unattended. Of course for the experienced/knowledgeable among us, no problem, but for those of us just learning, no way.
To Erco's post above, I'd add "test your device for proper continuity/noncontinuity first, then with low voltage from a battery, making sure it does what you expect before connecting it to a wall socket". Of course I don't think that's necessary if you go the X10 route, but with anything homemade, I think it's an important couple of steps.
Post Edited (sylvie369) : 1/16/2009 12:23:11 PM GMT
example: web1.automationdirect.com/adc/Overview/Catalog/Relays_-z-_Timers/Solid-State_Relays
or build your own