ryeeson
Newbie level 3
lm3915 a-weighting
I want to design a input circuit for my Sound Level Meter with LM3915.
this is my first project with an audio signal. LM3915 is bassicly a display driver.
the aim of this project is to display the signal received form microphone to sound level meter. example, let say the Mic receive a noise from sorrounding area(people talk), then the Sound level meter will be able to display(LED light up) the noise signal.
the input should be from computer mic or 8 ohm 0.25W mic.
so the circuit connection should be look like below.
Mic=>peramp=>rectifier=>LM3915.
do i need a rectifier here?
what thing i should consider in my preamp stage?
what is the peak detector for? peak detector=rectifier?
This sound level meter will monitor the noise caused by the student at the library table. That is, the corresponding LED will light up when the noise increased.
so the LM3915 must be cascede in order to display within 60dB range.
Help me. i hope i have a details explaination in the preamp and rectifier stage. what Opamp do i need.. how much power and also the frequency ..
thanx
I want to design a input circuit for my Sound Level Meter with LM3915.
this is my first project with an audio signal. LM3915 is bassicly a display driver.
the aim of this project is to display the signal received form microphone to sound level meter. example, let say the Mic receive a noise from sorrounding area(people talk), then the Sound level meter will be able to display(LED light up) the noise signal.
the input should be from computer mic or 8 ohm 0.25W mic.
so the circuit connection should be look like below.
Mic=>peramp=>rectifier=>LM3915.
do i need a rectifier here?
what thing i should consider in my preamp stage?
what is the peak detector for? peak detector=rectifier?
This sound level meter will monitor the noise caused by the student at the library table. That is, the corresponding LED will light up when the noise increased.
so the LM3915 must be cascede in order to display within 60dB range.
Help me. i hope i have a details explaination in the preamp and rectifier stage. what Opamp do i need.. how much power and also the frequency ..
thanx