I am going to attempt to build a wireless dimmer for a light in my appartment. I think I know how to handle the user end (the knob) and the wireless communication, but I do not know how to do the following:
Whatever electricity i get out of the wireless receiver, i need it to regulate the voltage (AC) that then goes to the light fixture.
How do I regulate this AC voltage?
neutrino,
You are crossing into a dangerous area of electronics, high voltage. Without a thorough understanding of safety procedures and design requirements for electronics devices connected to the mains wiring, this should not be something you should untertake. X10 products have a variety of wireless light dimmer devices that are available for relatively little money.
I cannot stress enough, that attempting to work on mains wiring in an apartment, puts others at risk from fire and shorts.
If it was a mechanical dimmer, you could move the pickup of the spool in the transformer to shorten the secondary coil, reducing the secondary voltage.
Garr… I was hoping there would be a product like a victor that would touch the AC current and deal with it for me… I would certainly never do anything dangerous, and would never hack something together when it touches my apartment’s wiring.
Google X10 and you will find a variety of different items.
To reiterate, it’s a bad idea for hobbyists to mess with 110V, even if they’ve had some experience in that area. Mixing high and low voltage electronics is tricky at best and dangerous at worst. That being said, I’ll put in a plug (no pun intended) for my former employer and sponsor of two FIRST teams (103 and 834), Lutron Electronics, www.lutron.com. Lighting control is their main business, mostly high-end stuff, good looking, and very reliable. They have remote controls for built-in and table lamps.
This is safely possible via a commercial dimmer that uses a TRIAC. It basically digitally sets a timing on the output at 60 Hz minus a delta, and the delta variable is what controls the dimming. Nothing ever gets hot, there are no pots that will over load and you’re not using more than the load of the light bulb in the electricity.
You can dynamically adjust the delta via a rheostat or the likes. Since this part is separate and isolated from the power supply it is safe, therefore perhaps you can figure out a wireless way to replace the rheostat.
If X10 doesn’t use a TRIAC and you’re sure you want wireless, you can look for an industrial-grade dimmer. TRIACs all basically work the same.
Jesse,
In order to limit the parts count virtually all dimmers have the Triac and associated circuitry connected directly to the mains at some point. There is no isolated power supply. X10 dimmers use Triacs. The decoding chip and associated electronics are designed to run at the mains voltage. There is no low voltage, isolated power supply making parts of it 120 volts above ground/earth. For ecomonmy of scale, large ligthing systems may mave a controller on one isolated power supply while the dimmers themselves are connected through optical couplers to help isolate the low voltage control from the high voltage load.
While the part itself works the same in different dimmers, the signal for controlling it can have many different implementations. Some use a simple variable resistor-capacitor scheme for charging up to the trigger voltage at different rates. Some use a fancier current source and voltage comparator circuit. Some have a digital counter or even a full microprocessor to adjust the trigger delay.
(I built a light dimmer a long time ago using a single-chip microprocessor that had onboard UV-erasable EPROM. It was designed to recognize a hand waving past it upward to turn the light on, and downward to turn it off. Moving from the top and pausing in front of it for a while would dim the light; moving from the bottom and pausing would brighten it. It worked for a while before getting erratic, and I lost access to the programming station I needed to change the code.)
Oh home electricity isn’t a big deal!
Funny I decided to finally make my own account to reply to this paticular thread…
Back when my dad and I were working on gutting and re-doing our rec-room we had a few sockets out, I wasn’t really paying attention when i grabbed the two copper wires around the socket with my finger tips and pop! goes my elbow.
It hurt and it was “shocking” but i lived.
But just so nobody fears for my life I learned my lesson and do my best not to mess with any possibly live wires.
I’ll go with Al and the X10. It is an old slow standard but relatively cheap and a whole lot of hobbyist articles have been written on it. Implementation is pretty much plug and play.
WITH THE FLUX CAPICITOR!