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Photo interrupter as a swicth

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noname06

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Hi, I am using a SFH 9305 photo interrupter for my project. Can anyone tell me the differences between putting a resistor before the anode and putting a resistor at the cathode end. Where should i put my output? At the emitter or collector leg? I have tried many times but when i block it nothing happens. How can I check if my photo interrupter is working. Thanks
 
Hi, I am using a SFH 9305 photo interrupter for my project. Can anyone tell me the differences between putting a resistor before the anode and putting a resistor at the cathode end. Where should i put my output? At the emitter or collector leg? I have tried many times but when i block it nothing happens. How can I check if my photo interrupter is working. Thanks

hi,
Connect pin 4 to 0V and a 4k7 resistor to pin3 , the other end of the resistor to +V, say 5V or 12V

You will need a resistor in the diode circuit to limit the diode current to less than 20mA.
 
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I've tried that but it still cant work..i guess the current at the emitter collector is too low as i measured out 23microA...in my project I've used the same source for the emitter and sensor part..How do i calculate out the current at the emitter collector side?
 
I've tried that but it still cant work..i guess the current at the emitter collector is too low as i measured out 23microA...in my project I've used the same source for the emitter and sensor part..How do i calculate out the current at the emitter collector side?

hi,
What voltage are you using for the emitter diode.??
Also ensure that you have not got the emitter pins reversed else you will get micro amps.

Have you ever applied a voltage to the emitter without a series resistor in circuit.??
 
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