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

[logan_dslasher]

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..  :'(

 

[audioguru2]

Alligator clips??? You can use them to short the mic, then completely remove them to see if the circuit works.

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.

 

[logan_dslasher]

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)?

 

[audioguru2]

High gain circuits like this one definately need the parts soldered onto a pcb.

 

[logan_dslasher]

High gain circuits like this one definately need the parts soldered onto a pcb.

alright then, i'll solder them..

about the pin configuration i was talking about.. could you please show it to me.. my adviser was worried that i had wired the parts the other way around... he wants to see its pin configuration.. i argued that you have already approved my PCB layout so, that means, i said, that i have correctly interpreted the chematic.. but for the sake of pleasing my adviser, may i please have a copy?

 

[audioguru2]

Sent while we were chatting on MSN and I saw you and your project on a webcam, while I was replying to your other thread and eating my lunch!

 

[logan_dslasher]

hey4! i didn't made it yo my first class.. i overslept..

i already cut the wires short enough but i havent soldered them onto a PCB yet.. i still dont have the mini drill i borrowed from a friend... maybe this afternoon..

i talked to my panelist for my final defence.. i inquired if it is alright if the prototype doesn't fundtion, they said yes.. it is not actually important if the project works or not.. what matters is that i tried to make it and was able to show them the output.. they said that i just have to explain why it didn't function..

anyway, since i have already made it beep.. i think you can already make the detailed explanation of the circuit   please remember that i wired the circuit like the one you showed me when you first modified it.. the buzzer was connected to the transistor's collector and the source. and there is a 4.7k resistor to the transistor's base and pin15..

please also include the LED i was talking about.. you said you would show me how to wire it.. the purpose of the LED is to accompany the beeping tone.. and also, if possible, it can be used as a mini flashlight..  i think i will have to use a separate source for the light so that the life span of the circuit would be extended..

still, i will try to make this thing to really work.. i'm just looking in the alternatives now so that i dont have to cram (this is cramming by the way..) by next week.. the schedule of the final defnce of the theses are up to next week only.. if i can't make my defence.. i i can't graduate.. and that's a bad thing!

thank you so much.. i am starting to write charpter 4&5 so i hope you could provide me with the circuit's detailed operation.. 

thanks a lot... ;D

 

[audioguru2]

It will work a lot better when its parts are soldered on a pcb instead of with long wires picking up interference on an intermittent breadboard.
I can add another transistor to blink an LED at 8Hz like the beeper, or make the LED light continuously when there is beeping. A bright white LED will need a 9V alkaline battery.
I'll write a detailed circuit description in my morning about 6 hours from now.

 

[logan_dslasher]

i will mount it on the PCB tonight.. after that, il'll read your post.. about the circuit DESIGN and OPERATION.. i hope this thing workz.. thanks a lot!!

 

[audioguru2]

Hi Logan,
In the Whistle Responder project, if the mic can hear the Beeper then the beeper will never stop. I have written a detailed circuit description to help you get it working and a recommendation for a simplification and improvement to its circuit. If these pics look poor, then save and open them.

View attachment 38410

 

[logan_dslasher]

it took my whole sleeping hours to have the final prototype of the whistle responder circuit.. i'm still very sleepy..

anyway, the circuit is still not working.. it's very frustrating.. any more suggestions that might get this thing to work.. when i picked it up to whistle close to the mic, it beeped.. i thought the whistle made it to work.. but i later found out that touching its bottom face, makes it beep...

is it still possible to put a light with the buzzer? i prefer the option that it will flash with the beeping sound... i think i better use a separate  voltage source for the light.. please remember that i plan to make a switch for the light so that it could also function as a mini flashlight..

thnks.. i need to sleep.. but where?! aha!! maybe later at my one o'clock class!! ehehe.. later..

 

[logan_dslasher]

i was browsing the eLab when i encoutered the fridge door alarm project.. when i opened it , i noticed that the latest post was yours.. even more surprising is what your post contains--- a BC337!! i was surprised to see that the first terminal (if you're facing the transistor) is the Collector.. whereas all this time, i thought it was the emitter..

i got so excited that i made a post in the wrong topic.. i am sorry, the adrenaline suddenly kicked in!! ehehe.... please acknowledge my concern.. thanks..

 

[logan_dslasher]

Source: http://www.nutchip.com

oh no!! what an idiot!!!  :-[ i have to go now.. i'll desolder  the transistor and rewire it.. i am so careless!! i hate me! i hate me!! ehehehe.. lolz... this is driving me nuts!! i need a rest!!

 

[audioguru2]

the circuit is still not working

What are its DC voltages without sound?

touching its bottom face, makes it beep...

What is a bottom face?
Circuits with meg-ohms of resistance and high gain can't be touched. It should be in a plastic box.

is it still possible to put a light with the buzzer? i prefer the option that it will flash with the beeping sound... i think i better use a separate

 

[logan_dslasher]

What are its DC voltages without sound?

pin2 - 2.8V
pin4 - 0.8V
pin6 - 0.8V
pin10 - 0V
pin14 - 2.8V
mic - 1.8V

when i reversed the pins of my transistor as what is shown in my last post, i haven't heard it beep even once..

 

[audioguru2]

Hi Logan,
If you ground pin 5 or pin 9, the beeper should beep at 8 Hz.

 

[logan_dslasher]

it didn't beep.. grounding pin 5 or 9 doesn't make it beep.. i kinda noticed that the site is down again..  maybe i'll just have to replce my transistor when i got home tonight.. i can;t solder here in the cafe..

our panelist said that even if our prototype doesn't function, they can pass my  topic as long as i can give an explanation why it didn't work.. what are the possible problems  that might have caused the circuit not to work?

 

[audioguru2]

This site is intermittent again. Let's continue on MSN.

 

[logan_dslasher]

http://www.gsmarena.com/alcatel_ot_club_db-25.php

i have this old cellphone which i found while i was searching through my box of "OLD" things.. it is an Alcatel OT Club db.. it's battery is dead and not charging.. it's almost two years since i switched it open. i think it's totally inoperable and repairing it would cost more than buying a new one. so, i'm wondering if i can use its earpiece or mouthpiece as the electret mic for my circuit..

 

[audioguru2]

Hi Logan,
I have my daughter's old cell phone that was run over by a few hundred cars.
I used its small electret mic in my FM transmitter, and now it is in my Sound Level Indicator project. It has a thin soft rubber sleeve around it.

Guess what? "You" logged onto MSN just now so I started chatting. "You" said, "i don't know you. im honesto of philippines". He has your e-mail address. He has your name Patch.

Anyway, I tested the cell-phone's small 32 ohm earpiece and it needed a small power amp to make a small beep. A little power amp would eat the battery too quickly. In the cell phone they must blast a lot of power to it to make it play ring tunes loudly.