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  1. bogdan2

    connecting an IR port to my mainboard

    what i want is to use a receiver and emitter..... i can't find those transcievers around here.
  2. bogdan2

    connecting an IR port to my mainboard

    my mainboard has a IR/CIR connector on it, so i want to connect an emitter receiver to it. the pinout on the connector is: for IR: VCC5 key IR-RX GND IRTX VCC and for the CIR: VCC5 stand by x CIR-RX GND x x i assume that x means not connected. if anybody can help, i need to make an IR...
  3. bogdan2

    produce electricity using quartz cristals...

    well, keep looking for that schematic.... i really want to try it... also, you know anything about generating power from a pletier moddule by heating it with a candle?
  4. bogdan2

    Flasher?

    Hearse, the first circuit is missing the current limiting resistor for the led. the second has a bit of a problem... for the second, i would increase the 220 ohm resistors...maybe to 560 .... i find the LM3909 unsiutable and expensive for this application. it is good for places where you want...
  5. bogdan2

    produce electricity using quartz cristals...

    Siddhu, this is what i have seen on tv some time ago, yet i didn't catch too much. do you know any website?
  6. bogdan2

    produce electricity using quartz cristals...

    when a quartz cristal is swueezed it produces some electricity. has anyone thought to use this for charging something? or maybe use this electricity to power something? these kind of things are used in lighters and other stuff. has anyone actually built this???
  7. bogdan2

    5 volt regulated power supply HELP!!!!

    the schematic with only the zenner and without the transistor can not suply you too much current. a 1.3W zenner cand suply a few miliamps(sorry, no time to do the numbers). if you want 5V, you might consider using a 5.1V zenner in place of the 4.7V one.
  8. bogdan2

    my first design.. pls help

    since you are using 4 diodes, this forms a full bridge rectifier. so you need to power your circuit from 0 and 12V. you could use 0 as ground and use 2 diodes, one from each 12V connection and you get a full wave rectifier also. here is what i mean... the 2 circuits show the 2 ways you cand do...
  9. bogdan2

    Lasersound

    well, i have seen something like this. you produce an ultrasound and modulate it in such a way that the human ear will hear as the sounds were at the correct frequency. since you can make the ultrasound unidirectional, i think that this is the sollution. still, making the sound perfectly...
  10. bogdan2

    led driver

    well, i meant to say that the circuit should work for 2 to 5V, and produce enough voltage for the led to light up in the same way, no matter the input voltage. so any suggestions?
  11. bogdan2

    led driver

    well, do you know any common driver, because here components are quite hard to find, so i need something common. maybe some other suggestions?
  12. bogdan2

    simple PWM

    i found this simple PWM for motor control. it is something usefull, and i was thinking to build it and wanted to know what others think. maybe some of you know a similar circuit, i mean, simple, but maybe more performant? here is the circuit: http://www.geocities.com/tjacodesign/motor/motor.html
  13. bogdan2

    led driver

    anyone cand suggest a led driver chip? one that requires few external components? it should be able to drive 1-2 white leds from a suply voltage like 2-5V....any ideas?
  14. bogdan2

    Flashlight without batteries

    one thing i have thought of would be to use a super cap and some rechargable batteries, and a led driver. this way you could charge the cap, adn also the batteries. the batteries will last longer than the cap. you oculd also add a solar cell to charge it from light. an interesting idea would be...
  15. bogdan2

    5 volt regulated power supply HELP!!!!

    now, you are now allowed to use a regulator chip.... but what about using a switching chip, with some extra components????? or building a switching with descrete components? if you can use a simple circuit with a zenner and a transistor. mixos, if you look at the second circuit you have posted...
  16. bogdan2

    MEASURING THD& on pc

    i think that the best way is to use the original load to mesure, or a load of the same impedance. if you put the original speaker to the output, then you have the corrrect results. now, second problem. if you power the amp from your car, then the voltage output is likely to be 12-14V. if you...
  17. bogdan2

    Convert 0-30V 3A PSU to 5A or more

    well, a bridge is better than 4 diodes, because it cools easier. this is because the surface of the birdge is highter than the one of the 4 diodes(maybe .....?!) and buying a 10A bridge is cheaper and uses less space than 4 diodes. now a switching mode suply could be done with about the same...
  18. bogdan2

    Electronic Stethoscope

    i'm glad you sortoed this out and your circuit works. can you post a picture of what you have buid? i would really much apreciate if you do so!
  19. bogdan2

    Convert 0-30V 3A PSU to 5A or more

    so................... ??? ??? isn't anyone still inerested in modifying the suply? ???
  20. bogdan2

    Keys finder circuit

    a good thing would be to create a SMD version of the circuit. maybe find a beeping cheychain, take it's guts out and put this in.
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