Can someone help me with this electronic light switch?!

[ownaginatious]

Recently I decided to make a mechanical electric device to turn the light switch on and off in my room using my computer's parallel port. I'm in a hurry right now, so I don't really have time to explain it. So far, I've been unsuccessful with the circuit diagram I've created below. I kinda don't really know a lot of electronics stuff, and learned what I made there off of wikipedia :p Can someone show me why this circuit I've created doesn't make the solenoid do anything? I'll explain more later today :p The transistor model is MJE13007.

edit:
I made the picture a link instead due to it being really big

http://img124.imageshack.us/img124/5664/img119yr6.jpg

[calumc]

i'm really no expert but wouldn't ypu need to have the transistor connected to ground on the paralell port?
also please resize your pic or just link to it

[dgrmkrp]

Well... I think I know where you are going with this.. If you wanna control the light switch in your room you just need yourself a powerful enough relay... That is what the transistor does (this schematic could have been simpler, as you do have 12V or 5V on your parallel port.. so no battery is needed), but in the case of a light I would steer of the transistor.. can be more complicated to design, but quieter... In the case of a light (?electric bulb or neon light type?), a relay would just have to be connected inline with the power line of the light... BUT! If you want to have dual control (manual and computer) at the same time, it gets more complicated... sticking with light controlled by computer: the relay should be 5V or 12V according to what you use and have a current rating of its coil in the same zone as the output of the port (it needs enough current to make the magnetic field, but not too much to damage the coil). Then you connect the power lines of the relay with the power lines of the light... and when you put the designated pin from the port on HIGH, the light turns on .. (also: needs software control this way, if u don't want your light to be on when the pc is on )

[Eclecticos]

Here is a Link that might help you out.

It's for LEDs, But it has a Little program you may be able to use.

[ownaginatious]

Sorry about the picture size, I didn't realize how massively huge it was lol. Well anyway, my idea was to have two solenoids that are each connected to a transistor. This way, when power goes through one, it would propel forward and hit my push button light switch, which depending on which solenoid was activated, would turn the light on or off. I'll put up the picture of the crappy model I made later if I can find it :p

I don't really want to use a relay because then I would have to disassemble my light switch, which could make things really complicated. Also, I want to wire up the switch so that you can use two electronic buttons on the device when the computer is off to be able to turn the light on and off. It would look kinda funny because it would be one of those machines where it's objective is to find the most complicated way to complete a simple task :p

Also, I decided to not directly wire my parallel port to the solenoid because I'm afraid I could accidently burn out the parallel port altogether within my computer if I do that. That would really suck :p.

... I gotta stop ending my paragraphs with :p.

[ownaginatious]

Here is my concept of what the thing will look like. The two solenoids move forward when a current is passed through them, thus pressing the light switch. 9 volts seems to work well when I tried connected the solenoid directly to the battery.

[Spawn-Inc]

dude, just get a clapper and hook it up to the switch. i will +rep you for the idea fore sure though.

[ownaginatious]

dude, just get a clapper and hook it up to the switch. i will +rep you for the idea fore sure though.

lol that would be a cool idea, but this project is already really complex for me as it is :p

On a side note, can anyone tell me what's wrong with my circuit diagram? I tried making it on a bread board as well, and it's not acting as it should. For some reason the transistor creates a circuit regardless of the state of the parallel data port. This happens when I attach the ground from the parallel port to the rest of the circuit following the emitter of the transistor, as I think was suggested by somebody above.

...I've been trying to figure out this light switch thing on and off for nearly half a year now

[dgrmkrp]

Ok.. Looked at the schematic and the assembly together and now I better understand what you mean, so just try using a resistor between the port wire and the base.. let's say.. 5v of voltage should need a resistor of 470 or less.. try different values.. this is because this type of transistor is current controlled, so you have to fix a certain current in its base so that it will typically allow a current hundreds of times larger to pass on the power side of the circuit. if you don't hurry and I remember, I could try some simulations (I'm not that good with practice in this area, although this will be my job someday) in the week end, after I assemble and make my power horse pc work again..

[ownaginatious]

Ok.. Looked at the schematic and the assembly together and now I better understand what you mean, so just try using a resistor between the port wire and the base.. let's say.. 5v of voltage should need a resistor of 470 or less.. try different values.. this is because this type of transistor is current controlled, so you have to fix a certain current in its base so that it will typically allow a current hundreds of times larger to pass on the power side of the circuit. if you don't hurry and I remember, I could try some simulations (I'm not that good with practice in this area, although this will be my job someday) in the week end, after I assemble and make my power horse pc work again..

I'm not really in much of a hurry, so if you could do a simulation and determine which resistor works, that would be great I tried doing it myself in MultiSIM, but I'm sort of lost when it comes to using that program Thanks for the help