Sunday, 30 October 2011

I have seen the light

After forty days and forty nights in the wilderness, wandering from website to website, wondering about the complexities of electronic lighting and winding up at least one sales rep on the way, the system worked!

Through the ingenuity of our electrician, making a test bed using two wires tied to a step ladder at one end, and a couple of nails on the wall at the other end, we were able to test the parts: the tension wire fittings, bought from the UK, made in Germany; the light bulbs, bought from the US, made in China; the power supply, bought in Japan, also made in China; the LED driver, bought in Japan, and probably made here. The parts were no doubt from Taiwan though. 

I had three worries about the system not working. One was that it would not work at all. Another was that there would be no dimming, and the elaborate current variation system would ultimately only give us an on-off switch. The third was that we would get dimming, but there would also be flickering as the different frequencies of the power supply, current control circuit and the electronics within the bulbs would cause beats and interference patterns. Another minor worry was that the bulbs would not produce even light, so one bulb would be at full brightness with another dimmer. 

In fact, we got bright, clear and even light from the three bulbs, which dimmed obediently as we turned down the volume. Unfortunately, the current control circuit we used will only dim to 50%. AudioQ have completely dimmable circuits, but only to lower currents: 0-350 mA, 0-550 mA, 0-700 mA and 0-1000 mA. These lower-current circuit boards are open, rather than in a box, which causes my electrician to pull excruciated faces.  Anyway, for three bulbs at full whack, we need 1500 mA, (12 Volts, 6 Watts), so 1000 mA is probably not enough. We chose their 1400 mA supply, which will only dim to 50%. In practice, dimming to 50% is probably good enough, although it's tempting to twist the electricians arm and get a 0-1000 mA dimmer circuit for the other three lights, which will effectively give us dimming from 30% to 100%, or brightness from 0 to 70%, in the other circuit. Now that the wires are in parallel, we could add extra bulbs, and for example have two bulbs on one light circuit and four on the other. The four bulbs wouldn't give any more light overall than than three, but would be able to spread it out more. 

The test took place in daytime, and the three lights certainly seemed bright enough, although it's impossible to give any idea of the brightness through a picture.  It's also difficult to be sure exactly how bright the lights will be when they are in place, and whether 70% of that really would be enough.