xl97's Iron Man motorized face plate tutorial
- Thread starter xl97
- Start date
JAnderson392
Active Member
I am attempting making this for myself and I have a question about the diagram on the first page. It shows the NPN transistors with a resistor on them but I am not sure where I can figure out that resistor value. I looked at the transistor data sheet but I am not sure if I know where to look.
Thank you,
Adam
Thank you,
Adam
JAnderson392
Active Member
I get how the 100 ohms for the leds is calculated, but where can I find the voltage for the transistor to know how to calculate for the 220 ohm resistor?
Thank you,
Adam
xl97
Master Member
you can use the datasheet (of the transistor) and check what is says to use..
Look at/for V[SUB]CE(sat)[/SUB] and see how it varies with different base current
it will vary on how much current you give the leds/how many leds you have...etc
I personally have 7 leds for my eyes. (I made some custom pcbs for this)
example:
in this one.. I have a 1K resistor I believe, which after some discussion on another forum (Arduino) was also suggested was 'ok/fine' to use. (talk of 'full open and full saturation of the transistor..etc).. anyways.......
fun pic of them on...
Look at/for V[SUB]CE(sat)[/SUB] and see how it varies with different base current
it will vary on how much current you give the leds/how many leds you have...etc
I personally have 7 leds for my eyes. (I made some custom pcbs for this)
example:
in this one.. I have a 1K resistor I believe, which after some discussion on another forum (Arduino) was also suggested was 'ok/fine' to use. (talk of 'full open and full saturation of the transistor..etc).. anyways.......
fun pic of them on...
Last edited:
xl97
Master Member
if "I" were doing this....
I would mold something to fit the eye socket of my mask.. (clay...whatever)..
then cast it it from some semi-trans white material/diffuser
I would probably try to mold in areas for my leds/pcb to sit into as well.
I made my own eye pcb's for the leds..etc
I would mold something to fit the eye socket of my mask.. (clay...whatever)..
then cast it it from some semi-trans white material/diffuser
I would probably try to mold in areas for my leds/pcb to sit into as well.
I made my own eye pcb's for the leds..etc
RocFoamArmory
Active Member
Hey guys I got an electronics question. I'm trying to power three 10w leds from an arduino. Each led needs 9-12v to run and my power supply for now is 3 9v batteries in series, so 27v. If I hook up the batteries directly to the leds they light up nice and bright, so I know the wiring is correct. Also, if I test the code on my arduino/breadboard with one 9v battery and a simple 3v led, it works correctly as well. How do I get the 27v needed for the led's while not shorting out the board with too much voltage?
xl97
Master Member
1.) Dont ever use +9v batteries. they just plain suck. (and dont provide a lot of current, which what you need)
2.) I guess I need to ask.. WHY the 10w LED? and why 3 of them? (overkill?)
Your already starting off with the 'odds against you' if you want to go this route.
maybe look at wiring them in series to keep the voltage down.?
hopefully you find a transistor/mosfet that works with your needs too..
what are the specs of the leds?
forward voltage needed? and current needs?
2.) I guess I need to ask.. WHY the 10w LED? and why 3 of them? (overkill?)
Your already starting off with the 'odds against you' if you want to go this route.
maybe look at wiring them in series to keep the voltage down.?
hopefully you find a transistor/mosfet that works with your needs too..
what are the specs of the leds?
forward voltage needed? and current needs?
