Intelligent IR Detector

[ahayes]

How do you make a IR Detector that's only sensitive to ~40khz pulsed IR and not the Sun or other IR sources? Everywhere I go all I can find are circuits that use a pre-packaged all-in-one IR reciever with the filter circuitry built in and I need something I can build from discrete components. I have a Radioshack 276-145 phototransistor, caps, resistors, 741 op-amps, 3904 and 2906 transistors, n and p channel power mosfets, 555 timers, 7400 TTL NAND gates, and a lm3909 LED driver.

 

[Nigel Goodwin]

Buy a pre-packaged one! - they are cheap, extremely easy to use, and work amazingly well - you're not going to build anything anywhere near as good!.

Building them from discrete components is challenging both on the design side, and also on the construction side as well - hugely high gain amplifiers are difficult to keep stable.

If you really have some perverse urge to do so?, try checking old TV circuits, back before the IC solution was available - although many used specific IC amplifiers, and it's essential to build it in a fully screened casing.

 

[ahayes]

Buy a pre-packaged one! - they are cheap, extremely easy to use, and work amazingly well - you're not going to build anything anywhere near as good!.

Building them from discrete components is challenging both on the design side, and also on the construction side as well - hugely high gain amplifiers are difficult to keep stable.

If you really have some perverse urge to do so?, try checking old TV circuits, back before the IC solution was available - although many used specific IC amplifiers, and it's essential to build it in a fully screened casing.

there isn't a store within miles that sells prepackaged ones, integrated components aren't an option for me because there is no way for me to acquire them and all I have is cash so I can't order anything online

 

[Nigel Goodwin]

Then take one out of an old item, TV's, VCR's, DVD players, stereos etc. all have them in - you're going to have to order other stuff to make one anyway, a 741 is no use to you.

 

[Papabravo]

there isn't a store within miles that sells prepackaged ones, integrated components aren't an option for me because there is no way for me to acquire them and all I have is cash so I can't order anything online

Then I would say that you are well and truly hosed. Your only alternative is to change locations or pursue another avocation. Why would you even suspect that it is possible to do what you want with the resources that you have? Globale economics will just not support that model anymore, and that is that. Tough rockos!

 

[ericgibbs]

How do you make a IR Detector that's only sensitive to ~40khz pulsed IR and not the Sun or other IR sources? Everywhere I go all I can find are circuits that use a pre-packaged all-in-one IR reciever with the filter circuitry built in and I need something I can build from discrete components. I have a Radioshack 276-145 phototransistor, caps, resistors, 741 op-amps, 3904 and 2906 transistors, n and p channel power mosfets, 555 timers, 7400 TTL NAND gates, and a lm3909 LED driver.

hi,
Looking at the components you have already, you should be able to build a 40KHz amplifier and detector.

Look at these links, in the Infra Red sections.

http://www.hobbyprojects.com/I/Infrared_Circuits.html
**broken link removed**
**broken link removed**

 

[3v0]

there isn't a store within miles that sells prepackaged ones, integrated components aren't an option for me because there is no way for me to acquire them and all I have is cash so I can't order anything online

That may not be true.

Start by filling out the location field in your profile so we know where you are. Once we know that we can help you find a place where you could order parts with a money order...