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Topic: What transistor shall I use? (Read 212 times) previous topic - next topic

spider920

I have a project where I build a Nikon camera IR remote control, similar to Nikon's commercial ML-L3 but with timelapse possibilities. It works well except that the distance between the remote control and the camera is only about 1 meter. This is when I push almost 40 mA through the IR-led.  I have IR-LEDs from Kemo Electronics and according to some page on internet (not Kemo's) it can handle 100 mA. If so, the working distance may be improved.

I've understood it is possible to use transistors to amplify the current, but there is a whole jungle of them. Any ideas on its specification and what to use?
I will run my Arduino Mini with a 9 volt battery.

ted

What arduino role is here ?
Buy extra infrared LEDs, they are cheap and do experiments, for short time they can handle higher voltages, the signal is not continuous 1 pulse, but bunch of short pulses

PieterP

Pretty much any small signaling/general purpose NPN transistor will do. E.g. BC548 or 2N2222 are popular.

Pieter

raschemmel

FYI,
I believe you can pulse them at 5 times the rated continuous current if it does does not exceed 10% duty cycle.
Arduino UNOs, Pro-Minis, ATMega328, ATtiny85, LCDs, MCP4162, keypads,<br />DS18B20s,74c922,nRF24L01, RS232, SD card, RC fixed wing, quadcopter

ted

#4
Mar 18, 2018, 11:58 pm Last Edit: Mar 19, 2018, 01:05 am by ted
Check what IC is there and what maximum Voltage is for it, most of them can work at 5- 6 V, if so use 2 X 3V batteries and se LED is dead or not after that.....

Wawa

#5
Mar 19, 2018, 12:02 am Last Edit: Mar 19, 2018, 12:07 am by Wawa
I have IR-LEDs
Then use them.
You can connect at least four IR LEDs in series on a 9volt battery,
(switched with an external constant current sink transistor).
Are you sure you got the frequency right. Single LED, 30-40mA, should at least do 3-5meters.
Leo..

ted

Then use them.
You can connect at least four IR LEDs in series on a 9volt battery,  = 20m. LOL


3-5meters. = In normal design, maybe camera producer reduced it for some reason or put low quality photodiode, or window for that diode is not clean - dirty.
Leo..


raschemmel

Arduino UNOs, Pro-Minis, ATMega328, ATtiny85, LCDs, MCP4162, keypads,<br />DS18B20s,74c922,nRF24L01, RS232, SD card, RC fixed wing, quadcopter

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