Waveshare 8-ch Relay Expansion Board for Raspberry Pi

Overview
The RPi Relay Board (B) is an expansion board with 8-ch relays for Raspberry Pi. It gives your Pi the ability to control high voltage products such as home appliances.

Features
1. Supports Raspberry Pi A+/B+/2B/3B/3B+
2. High quality relays, loads up to 5A 250V AC or 5A 30V DC
3. Photo coupling isolation, prevent interference from high voltage circuit
4. Standard rail mount bottom case
5. Onboard LEDs for indicating relays status
6. Relay control pin selection jumper, allows to control the relays by custom pins other than the default pins
7. Reserved control Interface, allows to work with controllers like PLC
8. Comes with development resources, including examples in wiringPi, bcm2835, python, python-bottle (webpage control), and crontab (cron job)

Specifications
1. Power supply voltage: 5V
2. Trigger signal: 3.3V/5V
3. Relay channels: 8-ch
4. Contact form: SPDT-NO,NC
5. Closed current: 6mA (per channel)
6. Connector: screw terminal block
7. Dimension: 232 72 (mm)
8. Mounting hole size: 3.0mm