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

[audioguru]

Of course the LED won't work if its battery has the wrong polarity.
If you replaced the tiny LR41 button cells battery with your power supply then the LED might be burnt out because it doesn't have a resistor to limit its current.

[logan_dslasher]

It's party time!! my LED is blinking together with the beep!! my defense is 13 hours from now!! wish me luck!! i'm gonna need lots of it!! thanks for all the help! it's not yet working though.. i'll work on it again after i finish my hard-bound manuscript!

thanks again..

[logan_dslasher]

hi there everybody!

i finished my  defense two  days ago.. it was fine.. i got 91% even if the circuit is not working..

[audioguru]

Congratulations, 91% is wonderful. ;D

Are you going to fix this Whistle Responder project's problems and post a re-design of it that works?

[logan_dslasher]

Congratulations, 91% is wonderful. ;D

during the pre-defense i got  94! eheh.. that's alright..

Are you going to fix this Whistle Responder project's problems and post a re-design of it that works?

i don't want all those components go to waste, of course i'll try to make it work.. but for now, i'm still working on the revision of my manuscript. i have to submit it tomorrow for final editing and printing.. iaudioguru, i  am sorry i left in such a hurry this aftenoon, i have visitors at home that is why i can't stay out for a long time.. there's no windows messenger installed on this PC.

can you please give me some readings about  linear amplifiers or anything that has something to do with my project.. (like about bandpass filters)

tahnks.. a good  website would do..

[audioguru]

Hi Logan,
We have posted two articles about using Cmos inverters as linear amps.
I just looked at Bandpass Filter in Google and found an article with exactly the same bandpass filter ircuit as in the Whistle Responder. I think that the project would have the sharpness of the filter at random since the input and output impedances of the linear inverters aren't known.

[logan_dslasher]

i'm sorry,  ive spent two days trying to come up with a good explanation why the circuit didn't work.. i have researched about so many topics.. i have read my saved MSN conversations with audioguru and so far, i still haven't got anything "acceptable" the panelist required me to present an explanation why the circuit was faulty. i have already said things like:

The IC used in the circuit is an old, simple CD4049 CMOS Inverter. Further research revealed that this IC is designed for a fairly high output current and therefore doesn

[audioguru]

Hi Logan,
The CD4069 linear amplifier has been documented as a high gain amplifier when it has a low supply voltage and was easily tested by me.
I have never seen a test of a CD4049 inverter that is used as a linear amp and I have never seen one. Why don't you set-up, test and document the gain of yours?

[logan_dslasher]

i have printed the final copy 2 days ago and this morning i had it bounded.. it's a nice feeling to have the finished study.. i just don't know if the explanations i made there are correct..

thank you very much for all the help..  ;D

[logan_dslasher]

it took us the whole Academic Year 2005-2006 to make this study.. and with the help of a lot of people especially audioguru, we were able to have the final manuscript printed and hard-bounded.. it took me some three months to have the courage to upload it here at eLab..  Anyway, i just want to share it here because, again, without eLab, i would have never come up with something like this..  ;)

thanks again..  ;D i am so grateful..

BTW, my work is open to criticisms.. you'll do me a great favor if you correct the mistakes i made in explaining some things in there..  8)

EIFv1.0.pdf

EIFv2.0.pdf

[audioguru]

Hi Logan,
You have a very nice manuscript.
It is too bad that you didn't have enough time to fix the faulty circuit by using a CD4069 hex inverter IC.

Correction: A Schmitt trigger uses positive feedback, not negative feedback to allow it to switch very quickly even though it has a slowly changing input.

[logan_dslasher]

thanks audioguru.. 8) thanks for the correction..
ato all those who wants to make a correction, please.. they are very much welcome..  ;D