Infrared light has a difference with ordinary light in general. We can see clearly when a light or light on an object.As with the infrared light we can not see the manifestation of these rays. Frankly I can not answer when asked why the infrared rays are not visible in the eyes of us. So at night do not hope you can make light by using infrared light. One thing that is often heard from many people that infrared light can utilized for the functions of a camera that can see in dark conditions is often called an infrared camera.
Actually I have explained the working principles of electronic circuit section in this blog is about the basic working principle of a series of infrared sensors are simple. To design this sensor circuit you should not find trouble if you ever make another series of sensors. It's just that the sensor circuit consists of the transmitter and receiver, to learn the basic principles of this series of infrared you can see in the Basic Principles Series Infrared Transmitter and Receiver. In the circuit this time I try to utilize the output of this sensor circuit as a trigger circuit counter or counters.
Picture series of infrared sensors | infrared sensor circuit scheme
1. Resistors: R1 (33K), R2 (1K), VR1 (Potensio 100K)
2. Capacitors: C1 (100nF)
3. Transistors: Q2 (BC547 should)
4. Photo transistor: Q1
5. IC: 40 106 (Schimitt trigger), 4026 (Decade counter)
In the transmitter circuit arrangement so that our task is only an infrared LED lights up and no shortage or excess of power, therefore, use 680 ohm resistors. On The set of photo transistor receiver serves as a useful tool sensor sensed a change in the intensity of infrared light. When infrared light is not on the photo transistor, the photo transistor is like a switch is open so that the transistor is in cutoff position (open). Because the collector and emitter open it in accordance with the laws of the voltage divider, the collector emitter voltage equal to supply voltage (logic high). The output of these collectors would make a series of counter counting irregularly if we did not dampen the bounce output to the input couinter. To reduce the bounce and clarify the logic signal to be our input to counter circuit, we use Schmitt trigger ignition. Schmitt trigger ignition is very useful for those of you who relate to digital circuits, eg, using the damping bounce of mechanical switches on the input digital circuit.
The series of counters that I use here is to use IC 4026 (Decade Counter), one of the family ic CMOS. IC counter counts up if this will get the clock input changes from logic low to high. This IC can directly connect it to the seven segment because the output is designed for seven segment mmang. So you do not need to use as a modifier decoder IC binary value into a score of 7-segment.To menmgatur you can rotate the sensor sensitivity potensio VR1 at a critical point, or if necessary you can replace R2 with a more appropriate value.