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.
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...
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
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....
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....
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?
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.