Wiring Circuit

Audio VU Level Meter Circuit with LM324

The 1K resistors in the circuit are capital so that the LEDs about-face on at altered audio levels. There is no acumen why you cant change these resistors, although annihilation aloft 5K may account some of the LEDs to never about-face on. This ambit is calmly abundant with added op-amps, and is not bound to use with the LM324. Pretty abundant any op-amp will assignment as continued as you attending up the pinouts and accomplish abiding aggregate is appropriately connected.

The 33K resistor on the schematic is to accumulate the arresting ascribe to the ambit at a low level. It is absurd you will acquisition a 33K resistor, so the abutting you can get should do. The amount of this resistor may charge to be changed, so it is best you breadboard this ambit afore absolutely amalgam it on PCB. The ambit in its accepted anatomy will acquire band akin inputs from sources such as the aux out on a Hi-Fi, all admitting could be calmly adapted to acquire apostle inputs.

The audio + is affiliated to the capital absolute rail, while the audio - is acclimated for arresting input. The 50k pot can be acclimated to alter the acuteness of the circuit.

High Frequency Waveform Generator Circuit Diagram

High frequency waveform generator is very useful in electronic experiment and design. This circuit generate sine wave oscillation, but actually we can modify the circuit to generate triangle or square wave function.
The core of this waveform generator is MAX038. This integrated circuit chip gives complete function to build a waveform generator/function generator.

• The circuit can be used to generate square wave, triangle, or sine wave by programming the pin inputs (A0:pin 3, A1:pin 4).
  • A0 A1 WAVEFORM
  • X 1 Sine wave
  • 0 0 Square wave
  • 1 0 Triangle wave
• The frequency can be controlled using current. If we disconnect the 20k RIN from REF (pin 1) and connect it to a DAC, then we can control the frequency using microcontroller or digital interface. We can even control the chip using a quartz crystal (PLL) by controlling the current using a phase comparator output that compares the sync output (pin 14 of MAX038) and a reference clock from quartz crystal oscillator.

This waveform generator integrated circuit chip is very interesting since it can generate 0.1Hz to 20MHz, very wide operating frequency, as expected for every waveform generator instruments.