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Controlling DC motor speed and direction with RF remote

Hunt2871

May 26, 2022
2
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May 26, 2022
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I am working on a project with a 12 V DC, 15 RPM gear motor and need to control the speed and direction of the motor with a RF remote. IR would be problematic because the operator may or may not be in sight of the receiver. In one mode I need to be able to rotate the motor at full speed in either direction while limiting the rotation between 0 and 360 degrees and the operator will stop the rotation between 0 and 360. There will be a device at the end of the shaft with wires that would wind up if driven past 0 or 360 degrees.

In a second mode I need to rotate the shaft in one direction at 1/5 speed (about 3 RPM) between 0 and 180 degrees and have the shaft automatically reverse direction at 0 and 180 degrees until the operator stops the motor. Variable speed in this configuration would be nice but a low speed for mode 2 and a high speed for mode 1 will suffice. I have an idea how to to build this circuit with a simple switch, a potentiometer, a DPDT relay and limit switches but it seems like a digital circuit would be more manageable than a analog circuit. I have not connected the motor to a ammeter but I suspect it would pull around an amp with little or no load (it will never have much load on it) and it would be almost useless without the ability to control it remotely. I have 12 volt DC power available and would like to keep everything other than the transmitter at 12 volts.

Eventually I will need to add at least one linear actuator that will extend the device and return it to its normal position. This will also need to be done remotely with the same remote transmitter that operates the motor. I may wind up having 2 linear actuators but I have some ideas on how to eliminate one of them.

Finally I would like to have the ability, although it is not absolutely required, to have hard wired switches at 2 locations that an operator could manipulate with the same configurations as the remote. At least one of these sets of switches would be operated by foot while the other would be console mounted. Any suggestions on the best way to do this? I am an OLD industrial electrician so I have some ideas of ways to do it with analog devices but I would like to keep the system as small as possible and it seems like a digital circuit would be far more manageable.
 

danadak

Feb 19, 2021
182
Joined
Feb 19, 2021
Messages
182
I would say this is straightforward to do with a micro, and position encoders or
stepper motors, and H Bridge to manage current and phase (direction).

The RF side a tad more complicated, both for electrical as well as safety reasons.
An ESP32 or ESP8266 would be a good RF (depending on distance you need) solution but
there is significant programming involved. I would advise hooking up with someone that
does embedded programming and has at least a passing knowledge in motor control and
power electronics. And especially in fault tolerant programming.

Regards, Dana.
 

Bluejets

Oct 5, 2014
5,985
Joined
Oct 5, 2014
Messages
5,985
An off-the-shelf 2.4g rc control perhaps.
Relatively cheap, mostly reliable and usually good range.
Depends on the selected model/type as to the programmable features but most have quite a range of options.

All mostly dependant on what the environment for operation is.
 

crutschow

May 7, 2021
511
Joined
May 7, 2021
Messages
511
I'm not sure this will do everything you want but here's an example of an RF remote controlled receiver that has four independently controlled SPDT relays.
I used the two-channel version with the relays connected in a bridge configuration to control a DC motor on or off in a forward or reverse direction.
It also has inputs for limit switches that can be used to turn off the relays at the end of the motor travel in either direction.

Perhaps two of the channels can control the full-speed motion, and the other two channels can control the slow-speed motion.
 
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