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  1. Shahriar

    Assisting the troops question

    Hi Sorry to say this in this forum; As I remember within these two years in electronic Lab, All people Teach good thing to each other; But this time I think Electronic Lab community is going to teach How to kill people; So I Do not welcome you PERSONALLY; Shahriar
  2. Shahriar

    need help... urgent

    Dear Ann I think there is no reply because nobody understand what you mean. What does  "about d park aid.." mean? HTH - Shahriar
  3. Shahriar

    Design of PC Speaker

    Dear smartsarath2003 A PC speaker is just a power amplifier. if you want to build a good one, look for a good Power Amplifier IC which you can find it in your area. there are two many kinds of these ICs. then download the datasheet and the rest is easy. your sound card acts as a good...
  4. Shahriar

    How Microwave Oven Work?

    Hi Does anybody know how microwave ovens work? How do they get things so much hot during seconds? ThanX in advance Shahriar
  5. Shahriar

    Telephone Billing machine!!!

    Dear Ante, Than you for your link. I will check it. Dear Audiguru the theory you said looks a little bit strange and if telephone designers Have done such a thing then they have challange a big problem. Imagine that ten years have passed and the goverments have decided to increase or decrease...
  6. Shahriar

    The is a VIZZ in the output Sound!!!

    Yeah, It can be  a possible. I will check it and tell you. Thank you very much Shahriar
  7. Shahriar

    Telephone Billing machine!!!

    ThanX all for your replies. Dear audioguru, I didn't say that long distance call sounds different. the pulses which I have heard about them is on both local call and long distance calls and you are not able to hear them. as I said I am not sure about this theory. I ask the question in another...
  8. Shahriar

    The is a VIZZ in the output Sound!!!

    Dear Alun The circuit is to creat a loud Beep. small buzzers can not creat such a loud sound. when I used a coupling capacitor between the output of opAmp and the transistor Base, the effect of my hand dissapeared, then I remembered that the PreAmplifier I had build, was a DC coupling...
  9. Shahriar

    The is a VIZZ in the output Sound!!!

    Hi I have build an square wave oscillator with LM324(which is a quad opAmp). I have connected the output to a TIP122(power Transistor) and drive a piezo to creat a beep sound. but the interesting problem: There is a VIZZ in the output sound. when I touch the Vcc or GND or some other points of...
  10. Shahriar

    What is the diffrence between24Cxx and 24Xxx EEPROMs?

    Hi When I found a EEPROM IC which do not work in a TV, I write new data (which I have read before from a working TV with same model)and it always work fine! But in some TV, the memory is IC is 24Wxx instead of 24Cxx fasmily. the when I try to read from them I usally receive bulshit and when I...
  11. Shahriar

    Frequency detection

    Tricky!!!  ;)
  12. Shahriar

    Telephone Billing machine!!!

    Hi So I think I guessed true. during a long distance call, I will receive more pulses during a minute! (Am I right?) {Dear Audioguru, if this is right, then it is how I am going to calculate the money!!!) 2- Do anybody know anything about the amplitude of these pulses? ThanX in advance...
  13. Shahriar

    Telephone Billing machine!!!

    Hi to everybody I plan to build a device that many of you may have thought about it before. (or may have heard about it ) The project is to be connected to telephone line. then when somebody hangs up the phone, he is not able to dial a number till he dial a specified number (i.e. 1111 for...
  14. Shahriar

    antennas and propagation

    Dear nylon Can you explain a little more. What is a Long distance meter????? Shahriar
  15. Shahriar

    diac

    Dear kosoniscs A diac Acts like a zener diode. in those usual dimmers, where a diac is places at the gate of triac, the diac breaks when the voltage acroos it, reaches somthing around 30V. the cap discharges. and the diac will turn off when the voltage across it becomes lower than 30 Volt...
  16. Shahriar

    Frequency detection

    Dear jarmund the sound of a human (your circuit input) consists of too many harmonics and difeerent frequencies. Usaully, the input of frequency meters are PURE sin or Square Waves. U can take a look at your graphic equalizer to understand what I mean!!! If you want a circuit to determine the...
  17. Shahriar

    Do we lose power, If we select a longer Antenna?

    ThanX all for your replies Shahriar
  18. Shahriar

    50.000V Powersuply

    Dear jarmund I do not have any plan for building such a high power project. But if you convince with a less power project, why don't you use a TV flyback transformer. it will gives you 25kV and nearly 100 watt (as audioguru said). and the schematics are available. but it really differs with...
  19. Shahriar

    Any document for RF amplifier designing!!!

    Dear 4-1000A Thank you very much for your replies. I took a book from my university. Its name is "Modern communication circuits". In one of its chapters all of the RF Power amplifiers is described. ThanX again Shahriar
  20. Shahriar

    calculator to TV remote conversion

    Dear shri_sam What I got from your writing is: you plan to use a TV remote control  IC and connect many  keys to it. then connect the output of IC to you micro. I said: use the whole remote control as a keyboard just use a Infra-red Receiver to convert the codes sent by remote control. I hope...
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