Line Follower IR Sensor

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Thu, 01/14/2010 - 15:09

robofreak

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Joined: 01/02/2010

bOt Points: 98

I have some queries regarding the line follower circuit given in this site-

I just cant understand why the pin 13(-ve) is connected to IR receiver in one and in other pin 9 (-ve is connected) to POT????

Also shouldn't the IR Receiver (i m using photodiode) should be reverse biased???

Thu, 01/14/2010 - 18:49

#1

shweta

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Joined: 04/16/2009

bOt Points: 139

Re:RoboFreak

I bilieve that must be the correction nedded in the circuit as they have explained above(in the tuorial) the connection IR sensor with LM324A. The post must be connected to + terminal....

Note:- This post has been edited by shweta at Thu, 01/14/2010 - 18:51.

Sat, 01/30/2010 - 15:10

#2

pratik20990

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Joined: 01/29/2010

bOt Points: 90

yes u r right....the pot must

yes u r right....the pot must be connected to positive pin....

Tue, 02/16/2010 - 09:53

#3

itshimanshubansal

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bOt Points: 54

query

1.why we use potentiometer in ir receiver?

2.Why pot is always connected to positive terminal?

Wed, 03/10/2010 - 15:23

#4

pratik20990

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bOt Points: 90

@itshimanshubansal An

@itshimanshubansal

An op-amp(lm324 in this case) consists of two types of input pins : +(non-inverting) and -(inverting). If V₊(i.e. voltage across positive input pin) is greater than V_- , then the ouput of op-amp is high.

1. we use the potentiometer to set a voltage which is just lower than the voltage across negative or inverting input of op-amp, so as when voltage across inverting pin decreases the ouput becomes high indicated by glowing led connected across ouput(the indication of IR rays falling on photodiode).

2. u must have understood the reason of connecting pot to positive terminal if you have understood the answer of your first question.