Make your own LED Sign VU Meter

ever since I started creating electronics videos there's been one repetitive question how did you make daily design in your intro and the answer is super simple dozens of led sold and parallel and powered by a constant voltage source but since that is too easy and even a bit boring for an electronics project video I will now show you how I created a new LED sign that features a volume units of you meter circuits that lights up the LEDs in correspondence with the loudness of the music let's get started first off we're going to need the LED sign itself for that I use the software off master reversed report templates to create my initial design by placing 73 green LEDs on the board to form the word music then I printed it out gathered my LEDs and started placing them on the boards in order to write the first letter make sure though that the anodes and cathodes all face the same direction in my case the anodes face upwards to solve them in place I simply bent their leads and after soldering snip them off but since this tactic does not fix the LEDs in that designated spot very well i heated up the solder afterwards once again and pushed a bit from the other sides this way the results look pretty decent I then repeated this process for every one of the remaining four that us which took about half an hour afterwards I got myself 0.

8 millimetre silver copper wire straighten it out with the help of two pirates and formed six bridges which jump across two holes of the strobe boards I used those around the other eye to connect all the anodes of each row together in order to create the so called common anodes at the end I sold a wire to each cathode line and one extra wire to the common anodes and the LED sinus completes I tested it out by applying the forward voltage of this LED type to the common a nodes and each cathode line and it all seems to work without a problem so we can move on to the control electronics this is the schematic that I came up with looks confusing at first but let me explain the main input signal will be the AC voltage of a 3.

5 millimeter jack which produces maximum voltage Peaks of around 1.

3 volts that is quite low if we want to distinguish them between seven threshold values for the seven rows of the led sign that is why the signal gets amplified with a non-inverting op-amp configuration after being mixed together to molo signal and amplitude fine adjusted by a potentiometer what we want in the end are peaks of around 8 bolts in the amplified audio signal this way we can build up seven comparator op-amp configurations which will turn on its outputs when the voltage of the + inputs aka the audio signal is higher than the voltage of the – inputs aka the reference voltage and by creating reference voltages from 1 to 7 volts with the air bubble to survive us we successfully differentiated between the volume levels also known as the voltage amplitudes of the music those output voltage boosts can then be connected to the gate of 7 RF d 220 n-channel MOSFETs which finally turn on and of the individual rows of the ad sign I only build up the circuits for the upper 3 rows 7 6 & 5 both on the bread boards but nevertheless it demonstrates the principle pretty well so I gathered all the parts I need for the complete control circuits and started by soldering the audio NTC jack to the left side of the board according to the schematic I then added the mixing resistors the potentiometer – 4 pin IC sockets for each quarter band by C the MOSFETs with pulldown resistors and finally all the resistors to set the amplification factor and creating the reference voltages while creating the circuits I try to use silver copper wire as often as possible to keep the layout neatly arranged but in the end I was forced to use a bit of flexible wire to hook up the op-amp outputs to the gate of the MOSFET and after two hours of soldering it was time for the first test so I connected a 12 volt power supply to measure the voltage at the ICS and two reference voltages induced Mouser scope to verify a successful amplification of my audio signal afterwards I mounted the buck converter to the board hooked it up to 12 volt power line set its output voltage slightly higher than the forward voltage of Melody's connected a positive output to the common anodes anti cathode lines to the drain of the corresponding MOSFETs then I drilled three millimeter holes in each corner of the two boards used 20 millimeter spacers and m3 bolts to join them together and the project was complete with the help of the potentiometer the circuits can be adjusted to pretty much every audio signal and of course it does look awesome especially with the lights out I hope you like this project and if you want to build something similar you can find all the necessary information in the video description don't forget to Like share and subscribe that would be awesome consider supporting me through patreon in order to keep such videos coming stay creative and now we'll see you next time.

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