Pong de Beer asked:


I want to make a light system in which the operator can turn on either one of the two lights with their own respective switch. Attached to one of the lights is a timer that will tell how long that particular light has been on.

I have little electrical experience but I doesn’t sound all that difficult. All I need is maybe a few suggestions as to what kind of parts to use/ how to assemble them.

Justin asked:


In my house, there is a dining room with two different light switches that control the same light. I always thought that a light switch works by opening and closing the circuit controlling the flow of electricity to the light.

However, if the light can be turned on and off by both switches then how does the circuit really work? For example, if I walk into the room with both switches set on off and the light is off and turn one of the switches on, turning the light on then walk over to the other switch turning it to on as well. Instead of giving the light more power, it turns the light off. This puzzles me because it shouldn’t be opening the circuit that the other switch is physically closed on.

wingles_angel4 asked:


I’m working on a project in which we need further research on light receivers. (InfraRed receivers are included into the search)

The Project consists of laser(or other lighting devices) transmitting signals, to a receiving device. We’d like to find the best possible option for this receiving device.

Along with Photodiodes(Either Current or voltage types), what are other types I should be looking out for?

Meiyu Z asked:


current LED screw-in light bulbs offer either low levels of light at a moderate cost, or moderate levels of light at a high cost. In contrast to other lighting technologies, LED light tends to be directional. some current models of LED are not compatible with standard dimmers. It is not currently practical to produce high levels of room lighting.

jim d asked:


If I have a facility that runs on 3phase 120/208 and I am charged .07cents per KWH and I shut off appx 250amps at night for lighting loads for 8hours how much money do I save a year and whats the formula, and does it matter being 3phase if all 3phases aren’t shut off equally proportioned?

wenleyicious asked:


What practical and safety considerations does a lighting designer need to to consider when designing lighting for a theater performance?

Carl asked:


I am designing this space where we want it to be bright enough to read and dim enough for mood lighting or TV watching. This can easily be accomplished via a dimmer. The question is how do I specify to a builder the level of lighting necessary to read by in terms that I can measure. I know the spec will be in lumens or foot-candles but I don’t know the level. Also where can I find specifications like this for various applications?