Position: Index > Audio Circuit >

Audio VU Meter(LM324)

2016-01-07 08:15  
Declaration:We aim to transmit more information by carrying articles . We will delete it soon, if we are involved in the problems of article content ,copyright or other problems.

This article briefly describes the Audio VU Meter (LM324). This principle is easy to understand, but also very practical. Depth understanding of circuit elements, can be more effective to grasp this principle. Do you know the circuit, for example, can understand and buy these components: LM324 .

This circuit uses two quad op-amps to form an eightLEDaudio level meter. The op-amp used in this particular circuit is the LM324. It is a popular IC and should be available from many parts stores. The 1K resistors in the circuit are essential so that theLED’s turn on at different audio levels. There is no reason why you can’t change these resistors, although anything above 5K may cause some of theLED’s to never switch on. This circuit is easily expandable with more op-amps, and is not limited to use with the LM324.

Circuit diagram:

Figure:1

Figure 1 

Pretty much any op-amp will work as long as you look up the pinouts and make sure everything is properly connected. The 33K resistor on the schematic is to keep the signal input to the circuit at a low level. It is unlikely you will find a 33K resistor, so the closest you can get should do. The value of this resistor may need to be changed, so it is best you breadboard this circuit before actually constructing it onPCB.

The circuit in it’s current form will accept line level inputs from sources such as the aux out on a Hi-Fi, all though could be easily modified to accept speaker inputs. The audio is connected to the main positive rail, while the audio – is used for signal input. The 50k pot can be used to vary the sensitivity of the circuit.

 

 


Reprinted Url Of This Article:
http://www.eeweb.com/blog/extreme_circuits/audio-vu-meter