Hello to all
I have found a lot of 8-chanel relay modules on the aliexpress.
Red boards are controlled by positive signal, blue boards by negative.
Relay needs more energy then output of most controllers, so relays has own power (can be 3.3, 5, 12 or 24v). To control relay by controller optocupers are used.
These boards are developed for use with 5v arduino output. I want to use with 3.3v output of w7500 board. But I can not found in docs - what optocuper are used there? Can I use it with 3.3v? What is minimal voltage to open optocuper? I reviewed boards datasheets but there is no any info about used optocupers and minimal signal level.
- relays are powered by automobile battery (12~14v)
- relays should be controlled by 3.3v of w7500 output
- relays load can be any, 220v for example.
It is custom alarm system. Car battery (used) is a big power bank) It shoul open electromagnetic lock or actuator if someone cut main 220v line.
Sorry for my English)