Comments on: Modulated IR sensor http://cognoscis.com/2008/10/03/modulated-ir-sensor/ Think. Understand. Apply Thu, 18 Feb 2010 23:02:08 +0000 hourly 1 By: Cognoscis » Blog Archive » Simple line follower http://cognoscis.com/2008/10/03/modulated-ir-sensor/comment-page-1/#comment-91 Cognoscis » Blog Archive » Simple line follower Fri, 06 Nov 2009 12:19:55 +0000 http://cognoscis.wordpress.com/?p=31#comment-91 [...] For this, LDR or IR sensors can be used. For construction of LDR sensor click here and for IR click here. Now, we have two sensors which are like two eyes of our bot. Using these “eyes” we [...] [...] For this, LDR or IR sensors can be used. For construction of LDR sensor click here and for IR click here. Now, we have two sensors which are like two eyes of our bot. Using these “eyes” we [...]

]]> By: Modulated IR sensor « Cognoscis http://cognoscis.com/2008/10/03/modulated-ir-sensor/comment-page-1/#comment-45 Modulated IR sensor « Cognoscis Wed, 05 Aug 2009 15:27:30 +0000 http://cognoscis.wordpress.com/?p=31#comment-45 [...] Modulated IR sensor [...] [...] Modulated IR sensor [...]

]]> By: How to make a PCB at home « Cognoscis http://cognoscis.com/2008/10/03/modulated-ir-sensor/comment-page-1/#comment-22 How to make a PCB at home « Cognoscis Sat, 04 Jul 2009 06:22:22 +0000 http://cognoscis.wordpress.com/?p=31#comment-22 [...] The breadboard has a circuit to generate 38 kHz IR signal for modulated IR sensor explained in my previous post. The second picture is a part of LDR sensors I made for my line follower robot. The picture has a [...] [...] The breadboard has a circuit to generate 38 kHz IR signal for modulated IR sensor explained in my previous post. The second picture is a part of LDR sensors I made for my line follower robot. The picture has a [...]

]]> By: cognoscis http://cognoscis.com/2008/10/03/modulated-ir-sensor/comment-page-1/#comment-26 cognoscis Tue, 31 Mar 2009 06:39:51 +0000 http://cognoscis.wordpress.com/?p=31#comment-26 Yes, You see the resistance 4.7 k will have more voltage drop across it. Meaning, less voltage to send the transistor to saturation. Hence, you need to reduce this resistance and you will be able to achieve proper biasing... Try reducing the resistance. It will definitely work. Reduce slowly. I think about 2.7 k will give you the desired results.. For more range, you can still reduce R4 from 47 ? to 22 ?. This will also give you proper biasing Regards Yes,

You see the resistance 4.7 k will have more voltage drop across it. Meaning, less voltage to send the transistor to saturation. Hence, you need to reduce this resistance and you will be able to achieve proper biasing…

Try reducing the resistance. It will definitely work. Reduce slowly. I think about 2.7 k will give you the desired results.. For more range, you can still reduce R4 from 47 ? to 22 ?. This will also give you proper biasing

Regards

]]> By: MorpHy http://cognoscis.com/2008/10/03/modulated-ir-sensor/comment-page-1/#comment-25 MorpHy Mon, 30 Mar 2009 09:58:41 +0000 http://cognoscis.wordpress.com/?p=31#comment-25 Well, the problem is that the output of the 555 it's about 13mV! I changed the 555 circuit but the problem persists! I changed the resistors: R1=120? and R2=180?, but i used the same capacitors C1 and C2. I rechecked the schematics and the way I soldered the parts, and it's ok... Any idea what should i try next? Well, the problem is that the output of the 555 it’s about 13mV! I changed the 555 circuit but the problem persists! I changed the resistors: R1=120? and R2=180?, but i used the same capacitors C1 and C2. I rechecked the schematics and the way I soldered the parts, and it’s ok… Any idea what should i try next?

]]> By: cognoscis http://cognoscis.com/2008/10/03/modulated-ir-sensor/comment-page-1/#comment-24 cognoscis Fri, 27 Mar 2009 09:59:00 +0000 http://cognoscis.wordpress.com/?p=31#comment-24 MorpHy: The circuit is a simple amplifier. The resistance R3 which is 4.7k? controls the base current. Hence, you can reduce it to get more current across your LED. You can reduce its value to as low as 300 ? without any problem. This will increase the collector current equivalently. Further reduction must be done carefully as there will be chances of the transistor being damaged. Hope this helps Also, to increase the range, do send the signals in bursts as explained by using a second timer at 1 kHz. MorpHy:

The circuit is a simple amplifier. The resistance R3 which is 4.7k? controls the base current. Hence, you can reduce it to get more current across your LED. You can reduce its value to as low as 300 ? without any problem. This will increase the collector current equivalently. Further reduction must be done carefully as there will be chances of the transistor being damaged.

Hope this helps

Also, to increase the range, do send the signals in bursts as explained by using a second timer at 1 kHz.

]]> By: MorpHy http://cognoscis.com/2008/10/03/modulated-ir-sensor/comment-page-1/#comment-23 MorpHy Fri, 27 Mar 2009 09:35:18 +0000 http://cognoscis.wordpress.com/?p=31#comment-23 Hy! I have a problem...i did connect all the wires as shown in the schematics, but the output is very low, it's about 13mV, and it can't switch on the transistor! Any suggestion?! Hy! I have a problem…i did connect all the wires as shown in the schematics, but the output is very low, it’s about 13mV, and it can’t switch on the transistor! Any suggestion?!

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