Evening All,
I've had a search, but can't find an answer to this.
I want to build a sound activated camera trigger - my previous effort leaves a lot to be desired. Straight forward mic > amp stage, but what I'm aiming for here is to drive a series of LED's as a sort of VU meter, and be able to select to level at which triggering occurs.
The circuit I have in mind is attached, the output of which would be then fed to an adjustable delay, and then via an optoisolator to the camera.
The bit I'm most unsure of is if the 3914's outputs going low would draw sufficent current from the transistor's base, or if the current through the LED would prevent this - and if so should I look at making the 3914 sink more current and add a resistor between the LEDs and selector switch?
An advise appreciated!
Regards,
Ian.
I've had a search, but can't find an answer to this.
I want to build a sound activated camera trigger - my previous effort leaves a lot to be desired. Straight forward mic > amp stage, but what I'm aiming for here is to drive a series of LED's as a sort of VU meter, and be able to select to level at which triggering occurs.
The circuit I have in mind is attached, the output of which would be then fed to an adjustable delay, and then via an optoisolator to the camera.
The bit I'm most unsure of is if the 3914's outputs going low would draw sufficent current from the transistor's base, or if the current through the LED would prevent this - and if so should I look at making the 3914 sink more current and add a resistor between the LEDs and selector switch?
An advise appreciated!
Regards,
Ian.
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