lapsap

after changing the IC, now it is working. but for some reason i will need to use my hand and touch the circuit then only is working. if i didn't do that, when the circuit is trigger, it will buzzing, stop, buzzing, as i mention it before. some have i mannage to use my whislte to trigger the circuit. thx, audioguru and others help me out.

hello, when i made a whistle the circuit cant be trigger, but then i knock on the table it start buzzing n when i made a loud sound. does that means the piezo i get is not good? becoz when i say piezo tranducer the shop keeper say no idea, so i get the piezo that without oscillator. after that i made a PCB, but now it cant be trigger even when i manually use the function generator to give signal. when i tested on the project board, when i knock the table, short circuit of T1's base n emitter or give signal by funtion gen for least then a second, it is trigger then buzzing for a short period of time then it stop. but after the PCB is done it only trigger when is short circuit of T1's base n emitter after remove the wire, it will instantly stop (what does this mean?) as for the name thing, thx for the suggest, Alun, it ok for me to mention this site and the name "audioguru", audioguru?

buy why when using a 9V battery will work instead of 12V battery? 12V battery low current? oh ya, mayi have your name? i m doing this as a project, can i put your name in my report?

after i change the 12V with a 9V battery, it works fine, it also can receive signal. but it seem like only whistle will not be able to trigger the circuit, i will need sound that louder. when i test wif power supply again, reduce the current, it seem like continuous beeping again, why? i did not change the IC1 to stop the continuous beeping sound.

i m using a 12V battery to test it, but when i using a 12v power supply it works fine. the only thing is that the mic cant pick up signal. can i put a mic parallel with the piezo, so that it can receive the whistle or some other signal. btw way, can i increase the gain of the amplifier? (N1...N3) what is this call? do you have any document for this amplifier so that i can refer?

mp3 is just a audio file, any media player will be able to play it. just in case here is the zip format, because this forum does not allow to attach mp3 files, i ll need to zip it up. now the problem i m facing is that, when i connect the circuit to the battery, the piezo will start buzzing for non stop, even there is no any sound in the environment except the piezo buzzing. when i remove the C1, the circuit will stop buzzing after a short buzzing. does that work as when there is no sound from the mic? but when the C1 remain there, i just disconnect the connection between C1 and R10, it will be same as the previous case, buzzing, stop, buzzing, stop... why do we need a C1 over there? sound.zip

after testing the circuit part by part, the circuit oscillation part finally working (i think so). but when i connect it to the battry, the piezo start buzzing, after few second it stop. and then start buzzing again. when i short the base of T1, the sound will non stop buzzing. R5 C3 N4 is the filter circuit? whats the name of this part? Quote: The integral circuit sound.rar

now i only connect N5, N6 R8, R9, C5. n connect the pie at output of N6 to the ground. there is a buzzing sound coming out. is this suppose to be the output sound? in this circuit T1 n T2 is suppose to be acts as switch? when the T2 turn on, the piezo is going to triggered, why and how? where is the signal come from to trigger the piezo? can i test the mic function by oscilloscope? how? which point should i connect?

sorry to trouble you again, i have just reconnect the circuit few times, but now when i gound the base of T1, it also do not have any sound. do you mind to explain everything? can i test the oscillator it self? with only the N5 N6 R8 R9 C5 how should i connect it to do piezo? connect the terminal of piezo to 12 and C5?

i have tested manually by turning on the T1, n let T2 on, in this case, you say that it will be triggered.but the sound is so soft can i increase the volume. but when i connect acorrding the circuit diagram given, the sound is also be triggered without any wistle. but the only different compare with T1 off, is that, when T1 is off, when is battery is connected the piezo start buzzing. when connect acorrding circuit, the sound is seem like charging up n start buzzing. another question is that normally the piezo will be connect at the collect and not the emitter. why? is the N5 and N6 part is the osillator? the connection is also differen from what i have found. thx you for your help...

haha... my place here is almost reaching sleepying time, maybe thats why that kind of sound is coming out. 8)

it sound like ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZzzzzzzzzzzz almost sound like tat, i dunno how to put it in words

thank you very much, i have really understand the circuit now. as for the fizzle sound, when i connect the circuit with a buzzer, there is some sound coming out from non stop. but it is very soft, i think that should be the fizzling sound.

:o thx for all the information. here it say that N4, C3 and R5 will ensures that the circuit will not trigger from common noise, what does it mean? is this consider as a filter? can i change the value so that i would need a high pitch voice to activated it? how is the calculation? after that it say that the voltage of N4 will increases to hight logcal level what does it means? sry to trouble you all again due to i lack of knowledge about circuit analysis

Posted by: Alun Posted on: May 28, 2005, 02:20:24 PM Insert Quote I forgot to say, the only difference between a piezo transducer and piezo buzzer element it a buzzer element has an extra feedback lead, a transducer just has drive and ground leads. Just connect the feedback and driver together and use the buzzer element as a transducer. back to my old question, whats the different between transducer ans buzzer? so it means that this transducer will act as a mic and then become a speaker to produce sound?