help in a sound sensor it's an emergency

Status
Not open for further replies.
Did you look up "Darlington transistor"? Two transistors with a gain of 60 will give you 60 x 60, so 3600. MORE than enough. And the current is very small. That 2N3904 will do very well, and it is easy to get.
 
so i have to buy 2 transistors 2n3904 and try with one if it doesn't work i connect it whith the second thx ur the best
 
i have another question lol sorry but this is the last:
when i want to put a resistor with "commad " (i don't know how to say it in english ) to control the quantity of the light i will put it insted the 300Ω resistor right?
and from ....Ω to ....Ω can i putt for it?
and the battery should be from 3v to 9v with the modifications right?
 
Last edited:
It will be better to replace R2 with the potentiometer for now. This is a very simple bias, and this is where you will need adjustment.
 
A guy who knows nothing about electronics and hardly speaks English is trying to make an LED flash with sound?
Using a mic, a preamp but no rectifier and no LED driver?
 
Oops. Did not see the second page. Meaning "Never mind".

Edit again: Might as well say that I enjoyed your posts very much in this thread, Duffy!
 
Last edited:
A guy who knows nothing about electronics and hardly speaks English is trying to make an LED flash with sound?
Using a mic, a preamp but no rectifier and no LED driver?

Yes, and I suspect he will learn a little something about biasing transistors in the process... afraid that circuit won't work very well. The light is on, mostly - but it DOES flicker if you blow on the mic hard, so I'll give myself half a point, after all - IT WAS AN EMERGENCY!!!!

**broken link removed**

If he's curious enough to increase that troublesome 100k resistor to a whopping ten megaohms, he will discover the LED gets quite dark when he yells loudly into the mic.

If he's further curious about biasing NPN transistors, he may discover the right way to do it (a 1 meg from the base to Vcc, 500k pot from the base to ground, no collector-base resistor) will, in fact, make the light light when you yell at it.

Does not need a recitifier, it's kept just below the 1.4V needed to drive the darlington.
 
i'm beck again guys thx for ur help :
can u show me the right way to do it duffy but i want it to be with a transistor (what is a meg?)
and for audioguru i'm still learning i'm trying but this is my first circuit i will ever make so it's my starting with the word of electronics so plz be patient with me and i maybe in the future u will ask and i will answer u
 
and forgive for the supid mistakes because i'm half world side from u so it was the 2 p.m for me and i was getting tired of searching
 
i've found a great one looooooooooooooooooooooooooooooooool
thx guys here is the circuit in the attachements
 

Attachments

  • manual_mk103.pdf
    148.1 KB · Views: 144
It is easy to design a simple circuit that blinks an LED when there is a sound.
 

Attachments

  • sound to blink an LED.PNG
    9.6 KB · Views: 123
$crooge's. One fewer transistor, charge pump on the base of the second transistor.

That first circuit will work, if you make it a Darlington transistor, and use a "voltage divider bias" with 1M (megaohm) as the top resistor and a 500k (kilo-ohm) potentiometer (connected as a rheostat) as the bottom resistor.

And if you don't mind yelling. The gain isn't impressive. Really needs three transistors.
 
Status
Not open for further replies.
Cookies are required to use this site. You must accept them to continue using the site. Learn more…