IR transistor

[Zener_Diode]

Hey
I bought IR transistor (VPT30A3 - vincenc company).
How does should it works?
I tried to bring closer my hand and it almost had no changes.
when I took tv remote control, it did me the same.

I want it work as a switch. when it detect IR Vce=0 when it not Vce=5V.

how should I do it?? it looks very simple but it doesn't work, and i don't know why.

thanks a head.

 

[Russlk]

you have to have an IR source. Sunlight will work, try that.

 

[zachtheterrible]

I would imagine you were probably using a voltmeter to test it's output. A TV remote's pulses would be too fast for a regular voltmeter to measure.

Can it measure IR energy in the heat range? I'm assuming that's why you mentioned putting it by your hand.

 

[audioguru]

I don't think your hand radiates much more heat than the surroundings. Under your arm will be warmer.
An IR transistor will probably be too sensitive with a 1M collector resistor. What value did you use?

 

[Zener_Diode]

I put 47K resister...

 

[Nigel Goodwin]

I put 47K resister...

Please post a diagram of exactly what you are doing?.

 

[Zener_Diode]

nothing complicated.....

 

[Nigel Goodwin]

nothing complicated.....

Try replacing the voltmeter with an oscilloscope, a remote control puts out short bursts of 40KHz, you're not going to see much with a meter.

If you don't have a scope?, then don't use a remote control, just use an IR LED fed through a current limiting resistor.

 

[audioguru]

The output of an IR transistor is very small. Most IR transistors have an amplifier following them with a voltage gain of at least 100.

 

[Nigel Goodwin]

The output of an IR transistor is very small. Most IR transistors have an amplifier following them with a voltage gain of at least 100.

Only to detect at long distances, that circuit is commonly used in VCR's for detecting end of tape and reel rotation, and in many newer models to replace the cam switch as well. In that type of short range use, they switch reliably from near 5V to near 0V.

 

[Someone Electro]

You can also conect it to the microphone input on your sound card and then and use get software that displays it.

This way you can see the wave forms.If you point it at lights you will see an 50 or 60Hz sine wave.If you point it at an TV you will also see an sine wne if you mehure the freq. you will know the TVs scaning speed.(This only works on CRT screens)

You can also see the remotes waveforms and on the spekaers you hear an tuut tuut tuut sound.

 

[Zener_Diode]

thanks for help...
I put an IR trasmitter near the transistor. I had almost no changes when the led turned on and off.

 

[aibelectronics]

reply

check your connections, still no result? think about changing the component.