OK, after having some fun with stereo version of the VU meter I described in my previous blog-post, now it`s time to do a serious stuff. Studio grade VU meter ! 24 steps, equallyspaced every 3 dB, covering Extra wide Dynamic Range from -63 up to +6 dB. Single (mono) channel this time, no messing around, absolute precision at the stake. Plus, it
Click here to download the full size of the above Circuit.
keeps absolutely Top-Flat linear frequency response from 40 Hz up to 20 kHz(*). I`m not going into details of RGB LEDs Display, which has no modification since Tears of Rainbow project, only plates installed in one line, form a single GIGANTIC bar-graph. There are some minor changes in mixing colors data tables, but they intuitively understandable. The most important feature in this project is autoscaling. As you, probably know, Arduino has 10 bits ADC. Only it can`t process negative half-wave, and for this reason it has only 9 bits available for AC measurements. According to DSP theory, maximum dynamic range is: As input audio waveform represents anything but perfect peak-to-peak 5Vsine-wave, real dynamic range would be lower. How much In first, there is a hardware limits. OPA (NE5532), which is: but, unfortunately, isn`t rail-to-rail type. Test results show, that compression becomenoticeable (~1 dB) when not scaled magnitude approaches level about 50 dB. That is in goodagreement with observed on oscilloscope notdistorted deviation peak-to-peak 2. 5 V. Or only half of full range of 5V. And as theory says, half is one bit less, and real DR = 1. 77 + 6. 02 x 8 = 49. 93 (~50 dB). In second, audio data is processed on block structure basis. It means, having average of the block 50 dB, doesn`t mean that there was no spikes in the sampling pull, thatobviouslywould be clipped and introduce error in the measurements results....
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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