Nov 13, 2012 #1 S snishanth512 Full Member level 3 Joined Nov 12, 2012 Messages 159 Helped 13 Reputation 26 Reaction score 13 Trophy points 1,308 Location India Activity points 2,135 Please explain with diagrams.... I am searching for IR LED of 940nm for my project.....
Nov 13, 2012 #2 tpetar Advanced Member level 7 Joined Sep 27, 2010 Messages 6,417 Helped 1,713 Reputation 3,456 Reaction score 1,673 Trophy points 1,393 Location Pancevo-Belgrade, Serbia Activity points 37,363 snishanth512 said: Please explain with diagrams.... I am searching for IR LED of 940nm for my project..... Click to expand... Explanation with diagram RX and TX : **broken link removed** **broken link removed** 940nm is wave length for particular IR LED, there is also other wave lengths... Do zou plan to make IR Remote Control, Illuminator for CCTV systems, Alarm sensor, Tachometer, ..... You should give more details what you need.
snishanth512 said: Please explain with diagrams.... I am searching for IR LED of 940nm for my project..... Click to expand... Explanation with diagram RX and TX : **broken link removed** **broken link removed** 940nm is wave length for particular IR LED, there is also other wave lengths... Do zou plan to make IR Remote Control, Illuminator for CCTV systems, Alarm sensor, Tachometer, ..... You should give more details what you need.
Nov 13, 2012 #3 S snishanth512 Full Member level 3 Joined Nov 12, 2012 Messages 159 Helped 13 Reputation 26 Reaction score 13 Trophy points 1,308 Location India Activity points 2,135 Why do we use resistor R2 in the diagram(given in the above reply)?
Nov 13, 2012 #4 J jeffrey samuel Advanced Member level 4 Joined Jul 23, 2012 Messages 1,092 Helped 107 Reputation 214 Reaction score 107 Trophy points 1,363 Location chennai,india Activity points 6,373 snishanth512 said: Why do we use resistor R2 in the diagram(given in the above reply)? Click to expand... Just to control the Collector Current of the above said design and fix our operating point in the required position
snishanth512 said: Why do we use resistor R2 in the diagram(given in the above reply)? Click to expand... Just to control the Collector Current of the above said design and fix our operating point in the required position
Nov 13, 2012 #5 tpetar Advanced Member level 7 Joined Sep 27, 2010 Messages 6,417 Helped 1,713 Reputation 3,456 Reaction score 1,673 Trophy points 1,393 Location Pancevo-Belgrade, Serbia Activity points 37,363 snishanth512 said: Why do we use resistor R2 in the diagram(given in the above reply)? Click to expand... Its Pull-Up resistor, and also he limit current and adjust sensitivity of phototransistor. **broken link removed** If you want to learn more about logic states see this link and use Nvigation field : https://www.electronics-tutorials.ws/logic/logic_1.html
snishanth512 said: Why do we use resistor R2 in the diagram(given in the above reply)? Click to expand... Its Pull-Up resistor, and also he limit current and adjust sensitivity of phototransistor. **broken link removed** If you want to learn more about logic states see this link and use Nvigation field : https://www.electronics-tutorials.ws/logic/logic_1.html
Nov 13, 2012 #6 S snishanth512 Full Member level 3 Joined Nov 12, 2012 Messages 159 Helped 13 Reputation 26 Reaction score 13 Trophy points 1,308 Location India Activity points 2,135 So, when the phototransistor receives the photons the output tries to go down to zero. It acts like an inverter. Right? I have a one more doubt i.e. what is the difference between photodiode and phototransistor? What modification should I do for using photodiode in the circuit?
So, when the phototransistor receives the photons the output tries to go down to zero. It acts like an inverter. Right? I have a one more doubt i.e. what is the difference between photodiode and phototransistor? What modification should I do for using photodiode in the circuit?
Nov 13, 2012 #7 tpetar Advanced Member level 7 Joined Sep 27, 2010 Messages 6,417 Helped 1,713 Reputation 3,456 Reaction score 1,673 Trophy points 1,393 Location Pancevo-Belgrade, Serbia Activity points 37,363 http://hades.mech.northwestern.edu/index.php/Photodiodes_and_Phototransistors **broken link removed**
http://hades.mech.northwestern.edu/index.php/Photodiodes_and_Phototransistors **broken link removed**
Dec 17, 2013 #8 F faryal Banned Joined Dec 15, 2011 Messages 29 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 0 what is the purpose or R1?
Dec 17, 2013 #9 G godfreyl Advanced Member level 5 Joined Apr 18, 2012 Messages 1,974 Helped 632 Reputation 1,266 Reaction score 621 Trophy points 1,393 Activity points 12,772 To limit the current flowing in to the LED to a safe value.