sun up alarm problem

[silvarblade]

hey i used 2n3906 transistor instead of 2n4403 in the sunup alram and 270k resistor instead of 300 k one and my sunup alram is not working properly. any substitutions.

 

[hentai]

can u please post a schematic of the alarm or a detailed description of it and whats wrong with it? Because i dont think those substitutions should cause problems...

 

[Roff]

I found the schematic. 2N3906 and 270k should work. You may have wired the circuit incorrectly.

 

[silvarblade]

I found the schematic. 2N3906 and 270k should work. You may have wired the circuit incorrectly.

i may correct my question. it is that the alarm is not working properly i-e it is ringing but very very faintly any way to increase its voice. i am using 4011 b ic

 

[House0Fwax]

How about posting the circuit diagram or a link to it as Hentai suggested. Then you may get some advice as to what is wrong.

 

[silvarblade]

here is the schematic diagram.

 

[House0Fwax]

The schematic gives no information about the 'speaker', what are you using in your design ?

 

[AllVol]

Doublecheck the pinouts on your 2N3906. You may have them backwards.

 

[kchriste]

That circuit has some flaws. Pin 13 floating is most likely the cause of your problem. For starters you should make the following changes to get rid of any floating inputs on the 4011:
connect pins 5&6 to pin 7 (ground)
connect pin 13 to pin 14 (power)
I haven't checked it for further functionality due to the fact that I really hate diagrams that aren't drawn properly like this one is....

 

[silvarblade]

That circuit has some flaws. Pin 13 floating is most likely the cause of your problem. For starters you should make the following changes to get rid of any floating inputs on the 4011:
connect pins 5&6 to pin 7 (ground)
connect pin 13 to pin 14 (power)
I haven't checked it for further functionality due to the fact that I really hate diagrams that aren't drawn properly like this one is....

this does take out the distortions but no help in operating. is the circuit correct or is it wrong any one ever made it?

 

[audioguru]

It is a stupid circuit.
Of course the output sound is low, the 220 ohm resistor makes an attenuator to the speaker. If the speaker is 8 ohms then its output power is only 12mW.
If the value of the 220 ohm resistor is reduced then the transistor will blow up.

The circuit doesn't have a supply bypass capacitor so the 9V is jumping up and down at the same rate as the speaker.

It buzzes continuously during daylight hours??? Why?

 

[kchriste]

this does take out the distortions but no help in operating. is the circuit correct or is it wrong any one ever made it?

Exactly what problem are you having with it? By but no help in operating do you mean that it buzzes all night or never?

 

[audioguru]

He said its problem is that it rings very faintly.
12mW is very faint, it would sound like a fly. It is a stupid circuit.

 

[kchriste]

He said its problem is that it rings very faintly.

Ok, that's what I thought he meant by, "this does take out the distortions" And by that I thought he meant the floating pin mods I posted above.

12mW is very faint, it would sound like a fly. It is a stupid circuit.

 

[silvarblade]

yeah i meant that your floating pin does take out the noise but it doesn't work.hey audio any tweaks to the circuit so i can make it work? cuz it isn't buzzing or any thing.

 

[audioguru]

The stupid circuit should have been designed properly.
This one should blow your ears off:

 

[Cry_Wolf]

Cool Circuit Audio

Why shud'nt we replace the speaker with a beeper.

simple a phototransistor, a NPN transistor and a beeper (plus few resistors !!!)

 

[audioguru]

A beeper would make it sound like a smoke alarm then eveybody will be running away.

 

[potatobanana]

dadadadadadadadadadadada

 

[audioguru]

Most little speakers do not like DC in them.
Why not use a little audio amplifier IC like an LM386?