Simple DC motor control? Fuse?

Thread Starter

bulaboo

Joined Aug 20, 2022
10
Hello everybody!

Any idea how to make a simple, robust, device (fuse?) that releases a relay when a 6 Volt DC motor is jammed, and the current exceeds ~40 mA?
Some kind of a shunt resistor and measuring the voltage?

All ideas, hints and advice are very welcome.
Thank you in advance!
 

Thread Starter

bulaboo

Joined Aug 20, 2022
10
How about something like this?
Let's assume that the motor is already running when this take place… Ignore the start current peak.

rotta2022.jpg

(Vout goes to the relay thru which V+ comes.)
 

Danko

Joined Nov 22, 2017
1,444
IMPORTANT >> Where do I connect V? Is it between R2 and C1?
As shown on diagram +V connected to node "A".
That's it. No more any voltages.
ADDED:
Motor connected between "A" and "B".
Motor shown as resistor.
ADDED:
Circuit for 6 V:
1661199245984.png
 
Last edited:

Thread Starter

bulaboo

Joined Aug 20, 2022
10
As shown on diagram +V connected to node "A".
That's it. No more any voltages.
ADDED:
Motor connected between "A" and "B".
Motor shown as resistor.
Thank you for the clarification. I somehow looked totally wrong. Now it makes sense, thanks!
 

Thread Starter

bulaboo

Joined Aug 20, 2022
10
Yes, resistance value of R3 is 3Ω.
Thank you!

Good News (for me): thanks to you guys I re-started my ”electronics hobby” :) It was on kind of a pause since 1980's or something. Now I try to learn use EasyEDA. Great stuff!
 

k1ng 1337

Joined Sep 11, 2020
687
Thank you!

Good News (for me): thanks to you guys I re-started my ”electronics hobby” :) It was on kind of a pause since 1980's or something. Now I try to learn use EasyEDA. Great stuff!
Get yourself an Arduino Uno. If you are only looking for minor precision to see if there is a large change in current, the ATmega328 microcontroller can handle that and plenty more. The onboard ADC can read a shunt resistor with little programming. Good luck on your quest and welcome to the forum.
 

Thread Starter

bulaboo

Joined Aug 20, 2022
10
Get yourself an Arduino Uno. If you are only looking for minor precision to see if there is a large change in current, the ATmega328 microcontroller can handle that and plenty more. The onboard ADC can read a shunt resistor with little programming. Good luck on your quest and welcome to the forum.
Good tip, thanks. I was considering do this with Arduino nano but in this case better do it analog.
In fact, this is a small part of a larger system that is ran by Arduino Uno. This DC Motor controlling is kind of a sensor and there are many of these, each working independently. I try to make it robust, less digital, simple…
But, I might be totally wrong and go back digital, hah haa!
 
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