Hi,
I am after a little advice about building an LED array project which I would like to have somewhere on the order of 100 LEDs laid out on a grid.
First of all, a question about power consumption. From my reading a single LED consumes around 20mA of power (am I right in thinking all different colours of LED are roughly equivalent, including more exotic kinds like the blue ones?). So If I have 2 AA batteries, which gives me ~5700mAh of power, I should be able to light a single LED for 285 hours. Or 100 LEDs for a little under 3 hours.
Just want to make sure I've done my sums correctly there.
Also, if this is the case, I'm probably not going to want to run this array from a battery. Even a bunch of D batteries won't give me a whole day's worth. And so, question 2; would it be a good idea to power something such as this by the mains? If so, how is this usually done? My only experience so far is with DC and simple battery powered circuits. AC scares me somewhat, especially the idea of plugging things into a 230VAC socket. Any pointers on sorting things like that out would be a great help.
Thirdly and finally, with big arrays of LEDs like this, I have read that the battery is unable to supply a high enough current, and so transistors should be used to step that up. I barely have an idea of what a transistor is, and can't quite appreciate how a transistor has this effect, but if someone could let me know the pertinent issues around current supply to an array of LEDs, I'd be very grateful.
Thanks all for your help and time!
- N
I am after a little advice about building an LED array project which I would like to have somewhere on the order of 100 LEDs laid out on a grid.
First of all, a question about power consumption. From my reading a single LED consumes around 20mA of power (am I right in thinking all different colours of LED are roughly equivalent, including more exotic kinds like the blue ones?). So If I have 2 AA batteries, which gives me ~5700mAh of power, I should be able to light a single LED for 285 hours. Or 100 LEDs for a little under 3 hours.
Just want to make sure I've done my sums correctly there.
Also, if this is the case, I'm probably not going to want to run this array from a battery. Even a bunch of D batteries won't give me a whole day's worth. And so, question 2; would it be a good idea to power something such as this by the mains? If so, how is this usually done? My only experience so far is with DC and simple battery powered circuits. AC scares me somewhat, especially the idea of plugging things into a 230VAC socket. Any pointers on sorting things like that out would be a great help.
Thirdly and finally, with big arrays of LEDs like this, I have read that the battery is unable to supply a high enough current, and so transistors should be used to step that up. I barely have an idea of what a transistor is, and can't quite appreciate how a transistor has this effect, but if someone could let me know the pertinent issues around current supply to an array of LEDs, I'd be very grateful.
Thanks all for your help and time!
- N