Opinions on this Light Sound Trigger circuit

[gvi70000]

I think i got the final circuit if i did the simulation correct
i didn't manage to make the sound trigger to work with 3v battery so I'll use two instead. The sensitivity level is set by the potentiometer...
so i need experts opinion on this, do you think will work?

 

[Audioguru]

Re: Light Sound Trigger

Don't use the transistors as emitter-followers. Then they lose 0.7V or more and since your power supply voltage is very low then the LEDs might not light. Instead use common-emitter transistors.

The LEDs and their driver transistors do not have current-limiting resistors so if the battery is new then the LEDs will burn out.

The absolute max supply for the LMV721 opamp is 5.5V and the max recommended supply is 5.0V. You are damaging it or destroying it with 6V.

Your circuit does not make much sense since the outputs of the opamps have a DC voltage all the time.

 

[gvi70000]

Re: Light Sound Trigger

I will try the common-emitter transistor configuration tonight
What can i do to not have DC output all the time?

 

[Audioguru]

Re: Light Sound Trigger

I will try the common-emitter transistor configuration tonight
What can i do to not have DC output all the time?

You can bias the opamp so without a signal its output is at 0V. Then a signal will cause its output voltage to be high on the peaks of the light or sound.

 

[gvi70000]

Re: Light Sound Trigger

Hi
In the sound circuit i use Q1 as a preamp and lmv721 as comparator. To adjust the sensitivity i use R2 (475KOhn is the measured value).
In the light sensor R1 adjust the sensitivity.

So...do you think that these circuits will do the job?

PS: In the common-emitter configuration the led will be lit when the op amp output is 0, right? in this case i have to use PNP 2N2907 instead of 2N2222?

 

[gvi70000]

Re: Light Sound Trigger

Anyone here ???