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The RoHS icon on this product indicates that the PCBs, components, solder, and chemicals are all lead-free and RoHS compliant. Additionally, this product is produced using a lead-free process. Unfortunately, we are currently unable to provide documentation confirming that this product is RoHS compliant.
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Package Includes:
This package does not include Din-Rail PCB holders and cables.
Notes:
- This package does not include Din-Rail PCB holders and cables.
- This board uses 4-pin connectors for I2C bus.
Features:
- PCF8574A I2C Bus Controller
- 8 relays (each capable of switching up to 30A)
- 100kHz I2C bus frequency
- Addressing via 3 jumpers, allowing up to 8 boards on one bus
- Supports up to 16 boards on a single bus(when using both PCF8574 and PCF8574A)
- Compatible with most microcontrollers
- Operating voltage: 2.5V - 5.5V
- Relay coil voltage: 12V
- Reverse polarity protection circuits for input voltage
- Relay contact rating: 30A @240Vac/24Vdc
- DIN-Rail mount compatible PCB size
- Board dimensions: 107 x 160 mm
This is an I2C relay board designed for high-current applications and heavy loads. It features eight relays, each capable of switching up to 30A of load current. Additionally, eight LEDs indicate the status of the relays. The board requires a 12V input voltage to operate the relays.
All relays are controlled via the I2C bus, managed by the PCF8574A I2C bus controller integrated into the board.
The PCF8574A communicates with a microcontroller and processes relay control commands. It supports an I2C bus frequency of 100kHz and is compatible with external logic voltages ranging from 2.5V to 5.5V. This allows it to interface with a variety of microcontrollers that operate within the same voltage range.
The board’s address can be configured using three jumpers, allowing up to eight different addresses. As a result, up to 8 boards can be connected on a single I2C bus. Furthermore, when using both PCF8574A and PCF8574 boards, a total of 16 boards can be connected on the same bus, since these controllers have different I2C addresses.
At a 100kHz I2C bus speed, 10K pull-up resistors are required on the SCL and SDA lines. The board includes two jumpers to enable or disable these pull-up resistors as needed.
For safety, all input voltage connections are equipped with reverse polarity protection circuits, preventing damage from incorrect wiring. LEDs indicate the status of the input voltages.
The board’s PCB dimensions are 107x160mm, designed to fit DIN-rail mounting supports for easy industrial installation. The DIN-rail system is widely used in industrial enclosures.
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Important: To prevent damage to the board, do not plug or unplug I2C cables while the power supply is on. Always turn off the power supply before connecting or disconnecting I2C cables.
