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| Help finding correct relays... |
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| MonMotha:
http://www.mpja.com/products.asp?dept=133 has a bunch of reasonably cheap SSRs ranging from "not small" to "pretty big". You cannot usually PWM an AC SSR as they (almost always) use Triacs. This means that they cannot be turned off until the AC current crosses zero. Lamp dimmers work by chopping up the AC waveform: they turn it on partway into the cycle and let it turn off at the zero cross, then repeat. This is called an AC voltage controller and is why you can't use a light dimmer on e.g. motors. It is possible to make an AC SSR using MOSFETs or IGBTs hich would allow arbitrary turn on and off, but it gets pretty expensive compared to the triac method, so they are limited to special uses. It is also possible to buy a SSR without zero cross turn-on functionality (but still zero cross turn-off) and use an AC phase reference to basically build a light dimmer. This is complicated and NOT SUITABLE FOR MOST HOBBYISTS (note caps) as it involves playing with components directly coupled to the AC line. Also, if you get it wrong, there are sometimes ways (depending on how you build it) to crowbar the AC line...not good. |
| paulscade:
X-10 is still slow. It wouldn't be a good choice to this: |
| cyapps:
--- Quote from: paulscade on September 26, 2008, 11:58:35 am ---X-10 is still slow. It wouldn't be a good choice to this: --- End quote --- I figured X-10 was to slow for the Christmas lights, I am currently looking at computerchristmas.com to see what others have done might be a more appropriate community to ask. But as you say X-10 should be fine for the game room lights. I believe there is a device called "firecracker" that controls X-10 from a pc com port (seen it originally on Hak.5 episode 1x01). |
| MonMotha:
There's the old CP-290 which has been replaced by something else I'm sure. All it did was send X-10 commands as usual, but it could be controlled via PC. There are all sorts of modules you can get to do control like this, but if you want to control a bunch christmas lights like this (especially if you don't need to dim them), then building your own will probably be the cheapest option. Just get a bunch of suitable SSRs and go at it. You can use a PC with any IO device of your choice or rig up (possibly a network of) microcontroller(s) to handle things. For things like the christmas light show, you probably don't need dimming, so things are likely pretty easy. If you want dimming, I'd recommend going with a prebuilt control system unless you feel comfortable dealing with real-time microcontroller programming and directly AC coupled stuff. |
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