10 Minutes Timer for AC Loads

The project described here is a 10-minute timer using an Arduino microcontroller, capable of driving AC loads up to 30A. The timer’s progress is visually represented by 10 LEDs, which light up sequentially, each for 1 minute, totaling 10 minutes. The project is powered by a single 230V AC supply, converted to 12V DC for the relay and further regulated to 5V for the microcontroller by an onboard isolated AC to DC converter and an LDO (U1), respectively. Snubber circuitry consisting of C8, and R18 are used on relay contacts to prevent damage to the relay contact and reduce arcing.

The operation of the timer is initiated by a trigger switch. Once activated, the microcontroller starts the sequence, triggering the relay and illuminating each segment of the bar graph one by one, with a 1-minute delay between each segment. This results in a total timer duration of 10 minutes, as each of the 10 segments represents one minute.

For the software side, the project utilizes Arduino code specifically designed for this 10-minute timer application. The code is downloadable and intended for programming a new ATMEGA328 microcontroller. It’s worth noting that the code can be modified to accommodate different time durations as needed. The project documentation includes references for bootloader and Arduino programming connections, providing a comprehensive guide for setup and customization.

This project demonstrates a practical application of microcontrollers in controlling and automating tasks, with the added benefit of visual feedback through the LED bar graph display. It’s a useful example for those interested in electronics and automation, showcasing how simple yet effective solutions can be developed using Arduino and basic electronic components.

Arduino Programming

More info about Arduino programming and bootloader: https://docs.arduino.cc/built-in-examples/arduino-isp/ArduinoToBreadboard/

Features

• Power Supply 230V AC
• Load up to 30Amps /230V AC
• 10 Segments Bar-Graph for Time (Each LED 1 Minute)
• On Board Trigger Switch
• On Board Reset Switch
• LED for Relay Operations
• 4 X 4MM Mounting Holes
• PCB Dimensions 88.98X53.96MM

Connections

• CN1: Pin 1= TX, Pin 2=RX, Pin 3=Reset, Pin 4=GND, Pin 5= VCC, Pin 6= D11, Pin 7= D12, Pin 8 = D13
• CN2: Optional, Do Note Install
• CN3: Pin 1 = Load AC-N, Pin 2 = Load AC-L
• CN4: Optional, External 12V Input in Case U4 AC-DC Converter Is not Used
• CN5: Pin 1 = 230V AC L Input, Pin 2 = 230V AC N Input
• D1-D10: LED Segments for Time Display
• D12: Power LED
• SW1: RESET SWITCH
• SW2: TRIGGER/TIME START

Applications

• Water Pump
• Fan
• Lights
• Geyser
• Heater

Schematic

Parts List

Connections

Gerber View

Photos

Video

LS05-13B12R3 Datasheet

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