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  1. walid1

    Programing an IC, how does it work?

    There are many things, ROM, RAM, ALU, buses ....etec there are a huge number of sites that talk in detail about this subject and u can easily find them using google
  2. walid1

    Broken Charger-connection Alert

    The circuit shown below is from: http://www.redcircuits.com/Page86.htm For me, it is easy to analys any circuit containing npn transistors, but i'm confused when come face to face with pnp type i read this in the same page: Circuit operation: The circuit is inserted between the supply...
  3. walid1

    Audioguru FM Tx

    Hi In fact i use An ordinary 7805 regulator with a table power supply adjusted to 9v. when i build it the first time on [a special board for experiment that with holes] i noticed some big short circuit, but after solving this problem and assuming that all was OK smell and touch all parts for...
  4. walid1

    Audioguru FM Tx

    Thank you guru it was a very good answer What question I forgot to ask about? thanks
  5. walid1

    a hi fi amplifier

    Hi I know what is an amplifier, but what the meaning of HiFi thanks
  6. walid1

    Audioguru FM Tx

    Hi all my friends, and special HIIIIIIIIIIIII to audioguru Now and finally i am going to build this FM Tx , yesterday i put all the components on the table and today afternoon i'll put them together my question is if i build my own receiver using TDA7000 or TDA7088 to receive signals from that...
  7. walid1

    pnp vs npn?

    I agree because this exactly what they teach us in schools guru start by this answer to force andrie to use his mind, guru is a good man with NPN Tr we connect collector to point more positive than emetter and make the tr ON by aplying a +tive voltage >= 0.7 V  with PNP Tr we connect...
  8. walid1

    BJT biasing formulas

    e) When Ic is high (look at Fig VD01 below) hfe (beta) is low, Zin is low   and VBE is high (Look at Fig VD02 to see how VBE changed with IC) f) When Ic is high it will drain your batt quickly NOW I want (as u may noticed in the figures) that Ic = 2mA 2mA means Isat 4mA 4mA = 9/[RC+RE] ...
  9. walid1

    BJT biasing formulas

    hi all Hi audioguru... my big teacher I'll show you here what guru taught me in the last 5 pages, then we'll continue to reach a high level... hope so WHAT I WANT (1) design a preamp (voltage divider unbypassed) (2) using the famous PN2222A transistor whose datasheets are attached below (3) I...
  10. walid1

    BJT biasing formulas

    Hi I back again to this very important subject first thank you audioguru you do a good work to make me understand i print this 5-pages subject after editting it in WORD and finally have 19 A4 pages i take it with me every where reading them. it is hard to read directly from the computer screen...
  11. walid1

    CM8870, DTMF Receiver

    OK Mr audioguru I may understand the general aspect of what u said but can u give me an example about this especially on your FM transmitter circuit. where the subcircuit or the parts that  do the pre-emphasis also in the receiver where it be placed in the whole circuit thank u audioguru
  12. walid1

    CM8870, DTMF Receiver

    i understand that it require a separate FM receiver i use this link but i have not any results but in this          http://www.alldatasheet.com/              i faound many i'm not understand this statement thank you
  13. walid1

    CM8870, DTMF Receiver

    (1) I read carefully the CM8870 datasheets but I can't conclude that it can     receive the FM signal directly or it must be connected to a separated FM     receiver please tell me (2) I hardly got the datasheets of CM8870/70C, but i really have CM8870PI     Is there any difference? thanx
  14. walid1

    Help with radio circuits

    This is also my problem, how to relate what you study with the practicle projects if u can't you waste five years in a universty all text books, net and persons talk about every thing but not about what you want i hope someone help u and me
  15. walid1

    simple question about batt chargers

    also my car does it without my attention, but i discuss for theory and then for using this theory as a designer, i told you that i live to learn To indulis thank you very much
  16. walid1

    Bigginers Handbook

    Please send a copy to me at
  17. walid1

    simple question about batt chargers

    yes, its a 3 cells Lead-acid batt
  18. walid1

    simple question about batt chargers

    I'm sorry, lets forget what i said before and start again .... the emergency neon lamp has a rechargable 6v rectangular batt if i want to charge it using 7.5 to 9 volt power supply and want to stop the charging process when the batt is fully charged using a voltage comparator at what voltage...
  19. walid1

    simple question about batt chargers

    ok ok ok i want to tell you that i recharge unrechagable batteries for years and reuse them it is never explode i have not faced any problem with them and after recharge them the last long time specially in remote control and sound toys i want that info to stop the charge process whe it must...
  20. walid1

    simple question about batt chargers

    audioguru i go to where you point me but nothing my question is very simple forget that it is charger assume that u connect a fully charged 3v batt to a 5v ps and measure the voltage across this connection what is your reading? thank you
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