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Will this work? Proximity sensor based circuit

kosmonavt

Oct 21, 2011
7
Joined
Oct 21, 2011
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Hello guys,

I want to make a simple circuit of a car that will stop when it is 10 cm from a wall.

The motor M1 drives the car. The components highlighted in blue dotted rectangle is an optocoupler. The IR1 is the sensor located at the front of the car. When the object is far away, the sensor passes a very low voltage to the comparator. When it comes closer to the wall, this voltage increases. The 10cm equivalent of the sensor is 1.3V.

So when the switch X is briefly pressed, a P.D. is created across the sensor IR1 and the comparator. The sensor passes a voltage which is less than 1.3 and therefore, the comparator gives an output of 5V as well. Now this 5V is being supplied to the NOT1 gate which makes the output 0V and the NOT2 gate again makes it 5V. This 5V is now being passed into the same optocoupler which we bypassed earlier (by the switch) so the supply becomes constant and the switch need not be pressed.

Apart from NOT1 gate, the voltage passed on by the comparator also drives a transistor which amplifies it to 12V which will drive the motor. AS soon as the sensor voltage exceeds 1.3, the comparator will stop its output and the transistor (and hence the motor) will stop also. The power to the sensor and the comparator will be shutoff. Is this a correct circuit?
 

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