I prefer to hack a VCR for the little black box, add in a 5 volt signal, and all IR goes high on the out put signal. Much simpler than even the transistor circuits.
Of course, although very easy to do, it does limit your detector to the 40KHz modulation theme of an IR remote and won't be able to check the operation of a simple IRLED operating in any other condition.
Dean
Dean Huster, Electronics Curmudgeon
Contributing Editor emeritus, "Q & A", of the former "Poptronics" magazine (formerly "Popular Electronics" and "Electronics Now" magazines).
Chris Smith wrote:I prefer to hack a VCR for the little black box, add in a 5 volt signal, and all IR goes high on the out put signal. Much simpler than even the transistor circuits.
Unscrewing the cover and hacking it, then looking for the black box, adding a 5 volt signal, then having to put back the cover...
This is simpler than my simple circuit loop that uses only a phototransistor, an LED, a resistor and a power supply?
The one I made decades ago will pick up a led signal at over a half mile away. Pulsed or straight.
Try that?
The transistor version I build back in the 80s took me several cascade transistors, photo receptor, black box for light, etc, and wasn’t as easy as you describe to make, but it did have 132 million to one gain.
Even the partial moon had to be filtered out.
Id stick with the black box idea, that and a POT for gain.
Many students here moan about spending 20 bucks on a project. Im sure there are plenty more. A Camera is not for every one. Used parts from the old is the way to start.
I tried it on my cell phone and it worked like a charm. If I didn't have a camera phone, I have at least 5 friends who do for a quick check of a remote (not to mention old phones without service which can be found for free if you ask around). With a camera, there is little to no chance of misinterpreting a signal from an extranious source too. You can almost make out the flicker from the modulation but it wouldn't be very diagnostic IMO other than indicating it is lit. Unlike a circuit I might build, I carry this detector with me everywhere.
You'll never convince you know who that a ubiquitous camera is at least if not more convenient than building a circuit of any complexity. On the other hand, the OP did ask for a circuit and that's what we gave him.
I wouldn’t use a cell phone but I do have dozens of Cameras, Night scopes, Infra red readers, cards, and just about every thing else I built over the years and experimented on.
I had a job that could easily pay for it all.
Not all people, especially students, are that rich.
Build lots of toys and get experience along the way, with your own hands and mind.
I wonder where all those poverty stricken students are. Oh, yeah, they are yacking away on their cell phones, listening to their iPods or fussing with their notebooks. But they have no money for a camera, camphone or webcam. something really must be done. tee hee hee
