Ok after reading the further replies i gathered that the 5v pin provides 200ma and that i can use this pin to power the led, then use a transistor to switch the led. And of course add the resistor to the led.My question i have is you have said that i can run 200ma through the led, but im told it is 50ma.Here is the led i have (should really have added this in my first post)https://www.modmypi.com/electronics/leds/super-bright-5mm-ir-led-940nm/?search=ir%20ledI also looked at the datasheet (download on link) and saw that dc forward current stated 50ma and then saw that peak forward current (1/100 pwm) was 1.2A.So from what i've been told and read on the data sheet is the led max current via pwm is 1.2A (not going to run at that level anyway) and the 5v pin can provide a max of 200ma safely (well rated but half should be better as not to run at max). I have tried to find a definitive answer to this and have read that the 5v pin provides 200ma, 500ma and 900ma but didn't find anything officially stating it. Also i will be powering via usb using a standard usb plug (the sort used for phone chargers, not fast charge ones).Just want to thank everyone for their help, knowledge and patience with me on this. Cheers.
You can get away with just using 2 i/o pins and no transistor.
Hi,You dont seem to be reading all the posts here. You can get away with just using 2 i/o pins and no transistor.
This is used for a remote.I suppose it is (or should be) pulsed 50%, so a peak LED current of <=100mA is acceptable for a 50mA LED.I picked a 22 ohm CL resistor for two LEDs in series on a ~4.6volt supply for a reason.Leo..
I did read that, the only issue with that is the library uses only pin 3 to do the switching, it's not an issue for me to use a transistor though i could still go that route for the powered circuit. I will see what works that is safe and go from there.Yes a remote sort of, more of an ir blaster so it will be static. I have 2 more leds that i can try with too then though wont be able to test for a couple days so will need to get back to you on that idea.
Yes a remote sort of, more of an ir blaster so it will be static.
If you want range without the high current issues, use a second IR LED.