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Hey audioguru, Thanks a lot for the help. Sadly, I didn't understand all what you said. Sounds too complicated. Regarding the -12, I meant the negative side of the +12, you can call it ground, or 0. Also, I have the power supply figured out for each circuit. That’s not a problem. I will be using the 78L05 regulator for the IR module, and 555 timers. Can you please explain in a more understandable way and a reason for each comment? Sorry :-[ for some reason I'm having trouble understanding you. Again, sorry. Also, I still don’t understand the capacitor-coupling regarding the IR beam continuously blocked. What is meant by "time-out?" Bye! ;D

What do you mean by "glass sensor and plastic sensor"?

Hi, I would suggest that you get yourself one of those cheap remote control cars and take out the guts. In my country, you can get an all direction car for about $4. I’m serious. I’ve already bought like 5 that I’ve dismantled and used one for a room alarm. Just replace the back (or front - used to steer the car) motor with a relay the same voltage as the batteries (or approx). Then use the Remote control to activate the relay using the respective keys to which motor you use. You'll probably achieve 20m in the open. This will save you big time and big bucks compared to building one yourself. Hope that helps. Bye! ;D

Hi, What you’re looking for is a "Remote Jammer" found at http://www.electronic-circuits-diagrams.com/funimages/funckt4.shtml I’m building a project which requires an IR LED to be oscillated at 56KHz. I thought, let me point the IR LED at the TV and see if the remote works. Walla, the remote was jammed. But I had to hold the IR LED very close to the TV's IR receiver. I guess this was because most TV remotes today operate in the range of 38KHz - 40KHz. I don’t think you'll achieve great distance with this project because remotes send data with the IR Light which can be picked up easier than just IR light. Anyway, let us know how it goes. Bye! ;D

Hi, I don’t know if you need this, but it’s a good idea to add a smoothing capacitor in parallel to the output of the rectifier. Something like 200V 2200uF. TAKE CARE ABOUT POLARITY. Why don’t you use a transformer? It’s safer and more efficient than a resistor. Also, what’s an electronic clutch? Bye! ;D

Hi all, I'v had this fasination of wireless electronics for a long time. And recently i had the though of wireless video. I have a webcam that i dont use and an old digicam. both have working lenses which i can take out. Are there any circuits to show you how to build a wireless camera because i couldn't find. The receiver can connect to the TV via AV or i can just tune the TV to receive the video signal. Thats pretty much what i have to say. Budget: $15. Small amount because i already have camera lenses and all i need is some components. I think! Bye! ;D

WOHO, hold up genius. I found a solution for my problem and I’m building it. It’s much simpler. Take a look. Explanation. The IR LED will be positioned across the door along with the IR Module on the same axis. The output of the receiver will always be high because it is receiving IR light at 56 KHz; this is why I added a transistor as an inverter to operate the relay. Thanks audioguru for the tip. I think I will also substitute the relay with a transistor. When the beam is broken, i.e. someone goes through the door, the receiver will output low, and the relay will be triggered and will trigger the monostable circuit which in turn will sound the alarm. I will actually add a relay instead of the alarm to switch on some lights. I just used the alarm to simplify explanation. Weird, I couldn’t find such a circuit on the web. I might add this to some electronics site. Wicked. What do you guys think? ;D Regarding the DC/AC inverter circuit, I think it should work properly. However, it was quite hard to set the 555 timer to 50Hz; it was not very stable and kept on increasing or decreasing by 1Hz every now and then. I don’t think this will be a problem for appliances that use rectifiers (i.e. Chargers). What about ones that don’t use rectifiers and work fully on AC current? PS: audioguru, can you please explain "You can capacitor-couple the signal to the monostable so it times-out if the beam remains blocked." Bye!

You have a point there MP, the reason I wanted to use the processor is because I couldn't get my hands of a PIC16F84 microcontroller. Guess I’ll just have to keep looking. Thanks all of you anyway. PS: did anyone have a look at the little robot and is thinking of building it?

Sorry, here's the image.

Hi guys, audioguru, I’m afraid the circuit you pointed me to is somewhat complicated and I don’t need 500W. Let me rephrase my question neglecting heating and power needed. If I were to oscillate 50 Hz using a 555 timer, then connect it the BE of a high power transistor to the output of the 555 timer, and the transistor's CE would be connected in series with a battery and a step up transformer (voltage of battery and output of transformer will be the same). Would I be able to power i.e. a 220v 5 watt light? I just want to know if the idea will work. Secondly, I managed to solve my problem. Weird no one though of this. I just got a 56 KHz Ir receiver module, and connected it correctly, to minimal components, (just a battery and a light) and when I switched on the oscillator and pointed the IR LED at the receiver, the light on the receiver lighted up. Wicked. However, can you please take a look at a block diagram I drew? Info is on the picture. I want to add something; the beam will be across the door, so when someone passes by...you'll understand when you see the picture. Thanks.

Hi, If i did manage to get hold of an old motherboard (for the P1 processor), how would that help? L8r.

Hi all, I once found this old computer thrown away, and to any electronics freak, one would take it and be happy ;D. I managed to get the Processor. I’m not sure of its speed, perhaps 166MHz (oh my god), and some 32MB ram sticks. Back then, I was quite dumb to throw the rest away. I also got a display (these where found in old computers to show you the processor speed). When I powered the display, it showed 166. That’s why I assumed that’s the processor speed. I used to have such a display in my old computer. Now, I read on some other posts on this website that the processor is a microcontroller. I was wondering, how can I make use of it? I once found this website for this guy who builds some funky stuff and one of them was a little robot that would... well check it out for your self. http://www.geocities.com/tjacodesign/cerberes/cerberes.html I couldn’t manage to get my hands on the PIC16F84 controller. Can someone please point me where I can build a similar project using the Pentium processor? Thanks

Dear Shahriar, I took a look at the circuit you pointed me to, but that’s not what I'm looking for. The circuit has no optical input (i.e. phototransistor), and has a reset switch that I don’t know why it needs it. I'll simplify things and ask a simpler question. How do you use the LM567 IC to receive a certain frequency via a phototransistor to operate an LED, for instance? Also, this is a side question. Would it work if you use a 555 timer to oscillate 50Hz (same frequency as the mains) then use an amplifier (with the help of a transformer) to operate low wattage 220v appliances? And would you need a centre-tap transformer? Thanks ;D

Hi, I’m no expert, but I think it would be quite difficult to use a POT to change the frequency of such small range. I have used the 555 timer for some time and am quite familiar with it. I have a schematic which I took of the Maplin catalogue which has worked quite nicely with me. I’ve digitized it. Have a look. Regarding the timing capacitor and resistors, I have calculated possible values to oscillate 20Hz Ra = 220K Ohm + 100K Ohm Pot in series (the pot should be set to about 80K Ohm). Rb = 220K Ohm C = 0.1uF RL = Resistor in series with the load. 100 Ohm would be OK for an LED. There is also a decoupling capacitor which can be attached in parallel with the power supply. 47uF 16V would be OK. Along with the schematic came a formula to calculate the frequency f = 1.44/[(Ra +2Rb)xC] Resistance in Ohm and Capacitance in Farad. To simply things so that you can use C (capacitance) in Micro Farad (uF): f = 1440000/[(Ra +2Rb)xC] Remember 1000000uF = 1F Find the schematic attached. All the components are very cheap. Most likely the 555 timer would be the most expensive part. Also remember that the resistors and capacitor have tolerance of about 10%. That’s why it’s a good practice to use a POT in oscillator circuits. You can try and tune the POT for different frequencies. Hope this helps. There are also many other circuits on the web. Bye!

Hi, Thanks Shahriar, but the problem is, I can’t find these IC's. I even looked in Maplin and some other shops but no luck. As you may have read, I have an LM567 Tone Decoder. I’m not sure if this will work, but would it be possible to use an NE555 timer to oscillate i.e. 10KHz and then use an LM567 (with some resistors and capacitors to set the frequency, I think this is how it works) to activate a relay when it receives only 10KHz? I’m just assuming how the LM567 works. Am I right? The 555 timer works using just 2 timing resistors and a timing capacitor, so I presume the 567 decoder would work similarly using resistors and a capacitor to set it to receive a certain frequency. Thanks. ;D

Hi, Thank you sooo much. I prefer building the circuit my self. So, the first link was the best. If you know any more similar links to the first one, it would be greeeeeat if you could share it. Again, thank you soo much. Bye! :)

Hi all, I’m in need of desperate help. I’ve searched ages for a simple circuit but failed to get one. What I have in mind is this. An Infrared transmitter will emit a signal which will be picked up by a receiver and when the path of the infrared beam is broken, the receiver will trigger a relay. The relay will be connected to an external circuit (i.e. lights, alarm etc...). For 5+ weeks, I haven’t succeeded. Can you please tell me where I can find a circuit of this type? A single channel remote control will also do the job. I don’t know if this helps, but these are some components I have (or that I can get): - NPN photo-transistor, - 56 KHz Infrared receiver module (Part number TSOP1756) - 555 Timer - LM308N OP-Amp IC - NE567N Tone decoder - Any resistor, capacitor, transistor (of course) - Infrared LED's - etc... I of course can also get other components. One more thing, I just thought of an idea. If I use a 555 timer to oscillate an Infrared LED at 56 KHz, can I use the infrared receiver module (TSOP1756) to KEEP a relay switched on when the beam hits the receiver? I thank you all very much for your help (that’s if I get any, hehe ;D). Later!