Build Your 4dB Peak Indicator Circuit Diagram

Description

This straightforward circuit acts as a peak detector for audio signals, signaling the crests of musical waveforms. Whenever the signal's amplitude surpasses a level of +4dB, the red LED (D1) illuminates. This design is applicable across various audio applications, including console channels, final amplification stages, and similar scenarios where peak detection is required. The circuit’s initial signal levels are calibrated to commence at amplitudes exceeding +4 dB (1.25V rms) due to the use of a trimmer capacitor prior to C1 for signal adjustment.

Circuit Diagram:

Parts:

Integrated Circuits Description

The circuit employs two BC550C transistors, commonly utilized NPN bipolar junction transistors. These transistors act as switching elements, responding to the input signal and controlling the LED’s current flow. The BC550C is a general-purpose transistor known for its robustness and reliability, frequently found in various electronic circuits due to its ease of use and relatively high current gain. Its low cost further contributes to its widespread adoption in both amateur and professional electronics projects.

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