Members kevinnem Posted October 9, 2007 Members Share Posted October 9, 2007 Hey all I was just thinking, .. I don't know if any one has tried this, but I am wondering your thoughts. - one thing I hate about conventionial lighting is that it takes a cable per light from the dimmer pack. IF we had a amp - rather then a dimmer, and we had 3 "carrier" waves on it, say a sine wave at 30hz , 100hz and 300hz ... could we build a "analog crossover" to split the wave out at the other end and have 3 control channels? We would be limited on total current we can deliver, but the concept is interesting eh? Kev Link to comment Share on other sites More sharing options...
Members IsildursBane Posted October 9, 2007 Members Share Posted October 9, 2007 You'd still have to run a cable to each light. If you want more channels, buy a dimmer with more channels. -Dan. Link to comment Share on other sites More sharing options...
Members 6Imzadi Posted October 9, 2007 Members Share Posted October 9, 2007 I you are talking about 120volts from the dimmer to the light, you will NOT be able to combine the signals the way you want. Electricity (for light bulbs) doesn't work that way. Link to comment Share on other sites More sharing options...
Members kevinnem Posted October 9, 2007 Author Members Share Posted October 9, 2007 You'd still have to run a cable to each light. If you want more channels, buy a dimmer with more channels.-Dan. yes, .. but you could just string *a* line to the tree and then split, rather then run a full length from the dimmer pack to EACH light. Link to comment Share on other sites More sharing options...
Members kevinnem Posted October 9, 2007 Author Members Share Posted October 9, 2007 I you are talking about 120volts from the dimmer to the light, you will NOT be able to combine the signals the way you want. Electricity (for light bulbs) doesn't work that way. yes, I am talking about plain old 120volt signal. now I understand that amps usally can't put out this voltage, but I am talking about a concept here. Link to comment Share on other sites More sharing options...
Members Gregidon Posted October 9, 2007 Members Share Posted October 9, 2007 I'm interested in how you would plan on "filtering" each frequency....? Not saying it can't be done, just wondering how you picture it being done.... Link to comment Share on other sites More sharing options...
Members agedhorse Posted October 9, 2007 Members Share Posted October 9, 2007 Cute idea but has some mighty challanging issues... 1. The wire would need to be larger because the sum of the three waveforms would still result in a power of 3x being delivered to the total load. 2. The sum of the 3 signals will have an amplitude varying but still having peak currents at various times in a period of at least 3x the single channel current. Have to look at the vector equations which reveal this. 3. Generating a varying level signal is technically challanging at these power levels. 4. You could in theory use 3 phase power which would solve some of the problem, but you still have 3 phase wires (channels) and a single neutral. Code now requires this neutral to be oversized when used in high harmonic conditions (this is). If you want to minimize the number of cable runs, the best solution is multicable made for this purpose. Link to comment Share on other sites More sharing options...
Members bassred Posted October 9, 2007 Members Share Posted October 9, 2007 Seems like if there was a problem with the way lighting cables worked, the industry would have addressed it. there is a lighting forum, you know...... Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted October 9, 2007 CMS Author Share Posted October 9, 2007 This is a concept very similar to what model train guys used many decades ago to control multiple electric trains on a single track. I'm not sure how many could be run at once, because of the problems Andy describes. Link to comment Share on other sites More sharing options...
Members agedhorse Posted October 9, 2007 Members Share Posted October 9, 2007 There was a 2-fer device that operated 1/2-wave with lower voltage bulbs (IIRC), 1/2 of the waveform operated 1 circuit and the other 1/2 operated the second circuit. Again, the limitation on 12 gauge cable was 20 amps full wave total, or 2 x 10 amp circuits in 2-fer mode. (note thatI am using 2-fer in the non-lighting vernacular.) Bill may have some info on this, I don't recall seeing it anywhere. It required special dimmers and lamps. Link to comment Share on other sites More sharing options...
Members IsildursBane Posted October 10, 2007 Members Share Posted October 10, 2007 yes, .. but you could just string *a* line to the tree and then split, rather then run a full length from the dimmer pack to EACH light. I guess I don't understand how you've got things set up. At my last gig, we'd have 4 500w Par 64's on a tree, with the 4 channel dimmer pack mounted in the middle of the tree. Each of the cans plugged into a separate channel output on the dimmer pack. So we had 2 cables going to the dimmer (DMX & AC) and one cable going from the dimmer to each of the cans. Are you feeding multiple trees off of one dimmer pack or is the dimmer pack some distance from the tree (or rackmounted)? If so, as agedhorse said, multicable is the way to go. -Dan. Link to comment Share on other sites More sharing options...
Members Ear Abuser Posted October 10, 2007 Members Share Posted October 10, 2007 While it could work, you basically need a high power bandpass filter for each frequency. The chokes and capaciotrs would get real expensive real fast (not to mention the transformer you'll need to get the voltage up to 120 volts.) Plus 1kw of dimmers a lot less expensive than 1 kw of audio power amp, Link to comment Share on other sites More sharing options...
Members agedhorse Posted October 10, 2007 Members Share Posted October 10, 2007 Subtract the losses of the filters and the amplifier and you are down by at least 50% before considering the other more major problems. Link to comment Share on other sites More sharing options...
Members BillESC Posted October 10, 2007 Members Share Posted October 10, 2007 You need one of these for each tree One of these for each tree and one at your DMX controller You are now wireless from your controller to your lighting positions. Just bring power to the tree, plug your fixtures into the dimmer pack and light away. Link to comment Share on other sites More sharing options...
Members 6Imzadi Posted October 11, 2007 Members Share Posted October 11, 2007 Bill, who makes the wireless thingy? Chauvet? Also, could this be used for audio? Link to comment Share on other sites More sharing options...
Members BillESC Posted October 12, 2007 Members Share Posted October 12, 2007 Yes, that is a Chauvet unit. It is not designed for audio. Phonic has a system for audio transmission that works quite well. We've used it in several demanding situations with little or no problems. Link to comment Share on other sites More sharing options...
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