This project aims to measure the output power of an audio amplifier based on a 4 Ξ© or 8 Ξ© load. The values are displayed on two 0.96" OLED screens via the I2C protocol. A DS18B20 sensor monitors the temperature, activating a fan if a critical threshold is reached.
The system is based on an Arduino Nano, utilizing a diode bridge, a voltage divider, and an analog reading for voltage measurement.
The load can operate up to >250W.
- Power measurement and display for two separate channels (left/right)
- Display on two OLED screens
- Activation of a cooling fan based on temperature
- Real-time monitoring via serial output
| Quantity | Component | Reference / Value |
|---|---|---|
| 1 | Arduino Nano | ATmega328P |
| 1 | Temperature Sensor | DS18B20 |
| 2 | 0.96" OLED I2C Display | SSD1306 |
| 1 | Diode Bridge | 1N4007 x4 |
| 1 | Filtering Capacitor | 20uF 50V |
| 2 | Voltage Divider Resistors | 82KΞ© + 10KΞ© |
| 1 | 5V Fan | 120mm |
| 1 | Fan Relay | 5V |
| 2 | Security Relay | 5V |
| 2 | Audio Connection Terminals | Jack / Banana |
| 4 | 100W Resistor | 2.7Ξ© |
| 2 | 100W Resistor | 15Ξ© |
| 2 | 100W Resistor | 2.5Ξ© |
| 2 | SPDT Switch | 1321S ON ON |
| 1 | LED + resistor | Red 2.5mm + 10kΞ© |
- Connections:
- DS18B20 to D12
- OLED Displays to I2C (A4, A5)
- Voltage Divider to A0 and A1
- Fan Output to D4
- Security relay R channel to D2
- Security relay L channel to D3
- Temperature indicator LED to D8
- Upload the program and voila !
http://tolisdiy.com/2021/03/30/compact-stereo-dummy-load-for-amplifier-testing/
https://andydoz.blogspot.com/2016/04/arduino-audio-wattmeter.html