Need Help With Relays

[BubbleManster]

I’m trying to use relays with a raspberry pi 4B to control motors in a robotic arm (I need clockwise and counter clockwise motion in the motors) and just learnt you actually need 2 relays per motor (I need to control 5 motors) but have bought a 8 channel module but actually I need a 10 channel module. Wondering if there is anyway to control a motor in both directions using a single relay? If not, could someone please provide me with an intuitive schematic for the wiring as the ones I’ve found seem very confusing. Any help would be appreciated.

 

[Bluejets]

You could use H bridges.

 

[danadak]

What is the motor current and voltage consumption ?

Is this speed control or simple on / off / direction control ?

A single DPDT Relay will reverse motor drive (single relay, off/on one direction, on/off reverse direction) -




Regards, Dana.

 

[danadak]

You can also use H Bridges to do this -

https://www.st.com/resource/en/datasheet/l298.pdf

This is a dual so would need 2 1/2 of them. Have logic level inputs, can do
2A, 40+V. You have to do thermal analysis to make sure you are not running them
too hot.

Relay H Bridge Driver Circuit, Simulation, and Arduino Programming

Relay H Bridge Driver Circuit, Simulation, and Arduino Programming- In this tutorial, you will learn how to design and make your own Relay H Bridge module.

www.electroniclinic.com

Regards, Dana.

 

[kellys_eye]

to control motors in a robotic arm

What kind of motors?

I doubt they are simple commutated motors - the usual practise is to use either servo motors or stepper motors as some form of feedback is always necessary. Both servo motors and steppers don't use straight DC voltages so relays won't work.