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logan_dslasher

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Posts posted by logan_dslasher

  2. i need help extending the keys finder project. can someone help me out????

    in Electronic Projects Design/Ideas

    Posted


    oh no!! i was just about to say that this is more like a anything-that-moves alarm than a whistle responder...


    This circuit has a very high gain. It should be on a pcb with very short wires to avoid picking-up mains hum. How did you change R1's value in a cafe unless they allow you to solder there?

    I hope you don't have the circuit on a breadboard. Intermittent contacts on a breadbord would cause the mic's voltage to change all over the place. The long connecting wires in the entire circuit would pick-up mains hum.

    YES. i still have them on a breadboard  :( and the tallest component is almost an inch long..

    when i try to check its connection and slightly bump to its components, it beeps!!! should i cut the wires? do i have to solder it in a PCB (which will have to wait  until tomorrow)?

  3. i need help extending the keys finder project. can someone help me out????

    in Electronic Projects Design/Ideas

    Posted


    the mic's volatge went up by 2V, now it's 2.2V..

    but why did it stopped beeping? the noise is still present.. even before i changed r1's value, it stopped.. no matter what sound i try to produce, it remains quiet.. the only way i can make it beep, except measuruing pin5, is by disconnecting-reconnecting it to the supply. the moment i reconnect the alligator clips, it beeps.. then remains quiet..  :'(

  5. Key Finder (pinoy version)

    in Feedback/Comments

    Posted


    i can say that it was certainly a good choice! i have already spent so much time on the whistle responder that i am more familiar with it than with the key finder...

    besides, i don't know what piezo speaker to use for its circuit. how will i know if the speaker can be used as a microphone?

  6. i need help extending the keys finder project. can someone help me out????

    in Electronic Projects Design/Ideas

    Posted


    Much too low. What resistor value do you have to connect it to 3V?


    R1 - 22K

    i think it's very sensitive. is there a way to lessen its sensitivity.. i think i remembered something about changing the value of R4 to change its sensitivity? this is not a whistle responder, it's a noise responder!! ehehe.. but i'm really glad it's working..

    by the way, i have it wired like when u first modified it -- with 4.7K to its pin15 and transistors base...

  9. Key Finder (pinoy version)

    in Feedback/Comments

    Posted


    because this circuit requires a piezo speaker, i decided to go back making the whistle responder circuit. i believe that the whistle responder is better because it has its own microphone unlike with the key finder circuit where the ear and  mouth of the circuit is its piezo speaker..

  11. i need help extending the keys finder project. can someone help me out????

    in Electronic Projects Design/Ideas

    Posted


    i am working again on the whisatle responder circuit to be used in my thesis.  i have finally convinced my adviser that this is a better one compared to the key finder.

    we have tested the circuit this afternoon and he concluded that my IC is damaged. i have replaced it already and guess what? it beeped. only two beeps. it beeped so fat that i think it didn't took a asecond for those two quick beeps. i don;t exactly know what made it beeped.. i tried making all sorts of sounds in hopes of making it beep again but to no avail..

    i tested its test points (reply#28) my test results matched them except for the mic voltage which is 0.2V (nearly 0V).. when i tested pin5.. it made short beeps  until i removed the test lead on it. what does that mean? athat's the first time that happend.. the transistor's base has 0V..

    i have the projct with me.. please tell me what to do with it.. i'll wait.. thanks..

  13. i need help extending the keys finder project. can someone help me out????

    in Electronic Projects Design/Ideas

    Posted


    1) "If the transistor has the 4.7k resistor in series with it like in my 1st modification of the original circuit, then you can test the transistor by shorting its base to ground to turn it off."

    the buzzer continued beeping.


    2) "Your mic is working properly now so maybe it is picking up the sound of the beeper which I think will keep the circuit turned on. Short the mic to ground for a minute to see if the beeper stops."

    even for two minutes, it didn't stop.


    3) "With R10 as 1.5M and C5 as 47nF as in the project's parts list then pin 10 of the IC should oscillate at about 8.5 beeps per second which maybe is too fast for your beeper to turn off beween pulses. Try 330nF or 470nF for C5 to slow it to about 1 beep per second."

    sorry i havent done that..

  14. Key Finder (pinoy version)

    in Feedback/Comments

    Posted



    Your piezo speaker didn't work in the other project that was modified for it so maybe it will have the same problem in this project. Get another piezo speaker that works.


    where could i get a piezo speaker? let's say i can't  buy one on an electronic shop because it is not available... how about the buzzer/speaker from the melody circuit of a Christmas light? or ma ybe the one from those greeting cards that plays a song as son as you open it?  are those speakers or buzzers? how could i test if it is working? will a piezo speaker beep (like a buzzer)  when i test it with an ohmeter?

  18. i need help extending the keys finder project. can someone help me out????

    in Electronic Projects Design/Ideas

    Posted


    i tried working on the circuit again. guess what? the moment i turn on the power, the buzzer kept beeping.. i tried to measure the circuit's voltage.. and found out that the transistor's base has a 0.5V which should be 0V.. i think i have to replace my transistor again. i have asked a friend to buy one for me..

    i am using 1M5 for R10 and 47nF for C5.. there's is also a 4.7K at the transistors base connected to pin15.. the negative terminal pf the buzzer is in the transistor's collector and its positive terminal with +V source..

    i already tried it with 4.5V, it didn't work. dont worry i won't go higher than 6V. the last time i did that, my transistor got damaged..

  19. i need help extending the keys finder project. can someone help me out????

    in Electronic Projects Design/Ideas

    Posted


    i really didn't quite understand your last two posts ;D, audioguru.. but get this. i have already found a piezo buzzer!!!! it's almost the same as what you have shown.. it beeps pretty loud with 3V.. i went back to the old circuit, the original one hoping that with the right buzzer, it would work, but.... as usual, nothing.. i tried making all sorts of sound/noise using different sources.. still, nothing./ now that i have the right buzzer, what could be wrong. maybe i don't need to work on a new circuit since i have the buzzer. i just have to make it beep when it is connected to the circuit...

    remember the DC voltage values i should get from different test points? they matched!! even the mic voltage (1.5-2.5V), were correct! i got a volatge of 2.3V across the mic!!

    what could still be wrong?

  20. Key Finder (pinoy version)

    in Feedback/Comments

    Posted


    i wasn't the one who changed those values. those were the specifications indicated in the copy given to me by my adviser.. I am planning to make the two of them.. if one doesn't work.. i'll try the other.. i have already purchased those parts.. and also the one indicated in the lab. problem is.. i can't complete them..  these are the parts i can't acquire:

    My circuit:
    - r2, r5, r8, --> 10M resistor (is there really a 10M resistor? i can do combinations right?)
    - c6 --> 10uF
    - t1, t2 --> 2SC3622  (2SC3245)  (2SC3248)

    lab's circuit:
    - c4 --> tantalum
    - c5 --> 1n5F

    can you please suggest replacements for them?
    most of the capacitors i've bought were mylar capacitors... was that OK? are they really supposed to be green-caps? is 6V enough for the circuit?

  21. i need help extending the keys finder project. can someone help me out????

    in Electronic Projects Design/Ideas

    Posted


    anyway, i'll still continue working on this circuit... i want to make it beep  ;)  not just now.. maybe after i have the new one working and i have already made my final thesis defence..

    i'm sorry for causing too much trouble...  :-[

    waaaa!! i have already started a new topic... i'll just delete that the next time i log in..  i have to go for now.. i have a class, and i'm late again (what's new?!)

  22. Key Finder (pinoy version)

    in Feedback/Comments

    Posted

    I've been working on the whistle responder (http://www.electronics-lab.com/projects/misc/008/index.html) project for my thesis. i can't get it to work. i'm trying a new circuit with basically the same principle - the Key Finder circuit (http://www.electronics-lab.com/projects/misc/002/index.html). However, I will use different values for most parts (esp capacitors) compared to the Key finder circuit in the lab/site.
    eC:\Documents and Settings\lawrence\My D
    the schematic is just the same except that i'm going to use this parts/specifications..

    R1         10K
    R2, R5, R8     10M
    R3, R4, R6, R7, R9 100K
    R10         4.7K
    C1         0.027/50V
    C2         56p/50V
    C3         15p/50V
    C4, C8       0.047/50V
    C5         0.56/50V
    C6         10uF/25V
    C7         0.1/50V
    C9         0.0015/50V
    D1, D2, D3, D4           1N4148
    T1, T2         2SC3622 (2SC3245) (2SC3248)
    IC1         4069

    i know i'm going to need a lot of help from you guyz.. i'll just post my questions the first time i encountered a problem. for now, please just standby..  ;D if you like, if you have already made this circuit, and have encountered probelms, please tell them now, so that, i can be prepared. 

    any suggestion or advice is very much welcome!! thanks a lot!!  :)

  24. i need help extending the keys finder project. can someone help me out????

    in Electronic Projects Design/Ideas

    Posted


    can we still figure out this circuit?

    if ever we really cant make this thing work, would the keys finder circuit (http://www.electronics-lab.com/projects/misc/002/index.html) be as much of a problem as this whistle responder? what do you think? should we try building the keys finder circuit? but i still say that we ought to continue with the whistle responder... it's just that i cant come up with any more guesses with what ius wrong, and especially how to fix it!!!

    i need your expert advice, audioguru, thankz...

  25. i need help extending the keys finder project. can someone help me out????

    in Electronic Projects Design/Ideas

    Posted

    ???  ???  ???

    sorry but i really didn't quite understand what those  info means...

    anyway, do you think there's still a chance i could pull this out! should i go to plan B? you have already seen the alternative circuit i was telling u about, would that be easier to build? assuming i can get all the parts it needed, would it be better..

    after i grounded pin5, yes, it gave the expected DC voltages.. but still no  beep!  :(

    i'll replace the mic later...

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