VM110N with VMA436 8 channel relay board


#1

I’m having trouble connecting a VM110N board with a VMA436 relay card. I cannot activate the relays on the VMA card…
Could you explain how to wire the VM110N digital outputs to the relay card inputs ?
Thanks in advance


#2

The VMA436 is not compatible with the VM110N.
The digital outputs of the VM110N are open collector outputs.
The VMA436 requires active voltage outputs connected to its inputs e.g. microcontroller outputs.
There is a workaround to get it working with VM110N:
You have to add external resistors (e.g. 220 ohm) between the IN terminals and VCC (5V) terminal of the VMA436.
Then connect the VM110N digital outputs to the IN terminals and GND to the GND terminal of the VMA436.
For more info please see this thread.


#3

Now I understand, quite clear.
I intend to use 12Vdc in my project. Should the resistors be 220 Ohm or it will be better to use 4k7 ones?


#4

The specified VCC voltage is 5V.
This is because the coil voltage of the relays is 5V.
The control input voltage is specified: 5 - 12 VDC
If you use separate 12V voltage source for the control circuit, then about 1k…2k2 ‘pull-up’ resistors should be OK.


#5

Thank you so much.
You have been very helpful on this topic.


#6

No problem. Glad to be of assistance.