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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.
Resources:
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Package Includes:
Notes:
- This board uses 4-pin connectors for I2C bus.
Features:
- PCF8574A I2C bus chips
- 100kHz I2C bus frequency
- Selectable I2C bus pulling-up resistors
- Address by 3 jumpers for use of up to 8 addresses
- Up to 16 boards on a single bus
- Compatible with most microcontrollers
- Supports 2.5 to 5.5V microcontroller ports
- 8 relay outputs
- 12Vdc coil voltages
- Relay contact rating: 0.5A @120Vac, 1A @30Vdc, 0.15A @48Vdc
- I2C operating voltage: 2.5Vdc to 5.5Vdc
- On-board reverse polarity protection circuits
- Small PCB size: 81.6 x 36.1 mm
This is an I2C relay board designed as a remote relay expander for I2C bus systems. It is perfect for applications where space is limited, and the board is based on the PCF8574A I2C chip. Both PCF8574 and PCF8574A boards can be connected on a single bus, supporting up to 8 boards or 64 relays. By combining both chips, a single bus can handle up to 16 boards or 128 relays.
The board operates with a 100kHz bus frequency and includes selectable pull-up resistors for the SDA and SCL lines, ensuring compatibility with various I2C systems. It features eight small relays with selectable coil input voltage, either from the bus voltage or an external voltage supply. The board also integrates inverse polarity protection to safeguard against incorrect power connections.
For improved convenience, the board is equipped with double 4-pin bus connectors, making connections simpler than previous versions. An LED indicator will light up when input voltage is applied. Additionally, the mounting holes are compatible with older versions of this relay board, such as EI2C-9AI and EI2C-9AIA.
Important Note:
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.
