*
The RoHS icon with this product means the PCBs, components, solder, chemicals are all lead-free and RoHS compliant. And this product is produced in lead free process. Unfortunately, now, we cannot provide documentation for this product is RoHS compliant.
Resources:
*
If your browser program can't show a pdf file on a screen completely, please save it into your computer and open it with a pdf reader program.
Package Includes:
This package does not include Din-Rail PCB holders and cables.
Notes:
- This package does not include Din-Rail PCB holder.
- This board uses 4-pin connectors for I2C bus.
Features:
- PCF8574 I2C Bus Controller
- 8 relays
- 100kHz bus frequency
- Address by 3 jumpers for use of up to 8 boards
- Up to 16 boards on one bus
- Compatible with most microcontrollers
- Board input voltage, 2.5V - 5.5V
- Relay input voltage, 12V
- Inverse polarity protection circuits
- 30A 240Vac/24Vdc contact rating
- PCB size fits on DIN-Rail mount supports
- PCB size 107.00x160.00mm
This is an I2C relay board. Also it is a heavy current relay board designed for very big loads. It has 8 relays on
board and each one can turn on/off load current up to 30A. Also there are 8 LEDs to show status of
the relays. The relays require input voltage 12V. All of relays are controlled via I2C bus which
the board has I2C bus controller, PCF8574.
The PCF8574 is the I2C bus controller which talks to microcontroller and
then takes commands to the relays. The PCF8574 supports 100kHz bus frequency.
And it can be connected to 2.5V - 5.5V external logic. This means that, it can be connected
to many microcontrollers that have 2.5V - 5.5V logic voltage of I2C port.
The board is addressed by 3 jumpers to make 8 different addresses. So that 8 boards
can be connected together on one bus. Moreover 16 boards can be connected together on one bus
when they have 16 different addresses. By this way, 8 boards of the PCF8574 and 8 boards of the
PCF8574A can be connected together on one bus. Because the PCF8574 doesn't have same
address as the PCF8574A.
Normally, when the I2C bus works at 100kHz. It need 10K pull-up resistors at SCL and SDA lines. On the board, there are 2 jumpers for enable/disable the pull-up resistors.
All of input voltages have inverse polarity protection circuits to prevent damage from a
mistake of connection. And have LEDs to show status of those input voltages.
Board has a PCB size fits on 107x160mm DIN-Rail PCB mount supports. So that the board can be installed on DIN-Rail easily. Din-Rail is the most use of enclosures for industrial.
To prevent damage to the board. Don't plug and/or unplug I2C cables on the board while a power supply still turns on. Turn off a power supply before plug and/or unplug I2C cables on the board.
