I am with this issue that IR emiter and receiver of FC-51 must fit in a small place, so I am cutting them and solder them on a 10 cm wires and I make 4 holes in the board, where they were attached
The legs of these IR LED result very short to solder and I wanted to use 3mm IR LED.
The thing here is that the LED I find all work with 1,2 to 1,5 V and my multimeter reads 5V feeding the IR LEDS that come with FC-51.
Can I use resistors on new IR LED? Or where can I find IR LED working on 5 V?
Duarte2019:
and my multimeter reads 5V feeding the IR LEDS that come with FC-51.
Are you saying that you read 5volt on the board holes after removing the IR LED.
That is normal.
Without current through the LED, there won't be any volt drop across the LED's current limiting resistor.
Just connect the external LED to the board, and then measure.
Leo..
I just figured that my IR sensors are MH-8 instead of FC-51.
Are there any diferences?
Yes, I know it must have resistences for tension to drop.
Yes, I measured 5V on IR LEDs terminals.
My problem is that after cutting LEDs, their legs get very short and it is dificult to solder them to extension wires. But it is doable.
And I wish I could use 3mm LEds isntead of original 5mm ones. My concern is that I can burn the new LEDs or, by adding new 1,5V ones, the resistors can give incorrect information to the IR board and to Arduino Board.
I may assume the resistors are on the board. So you replace one LED with another. Normally no problem. And if course with the LED gone and no current flowing you're going to see 5V