Measure dc current indirectly

[jfroage]

Good Morning,

I have a 12 volt trolling motor on my boat that uses wireless technology to change speed, The only indicator is a small "beep" when speed is increased or decreased. My hearing is so poor that I cannot hear the "beeps" and don't have a clue if the motor is running fast or slow or even if it is on or off. I need a visual indicator to give me this information. The current draw on the motor is about 7 amps on low speed up to 30 amps at the top speed. Since the current draw is relative to speed, I would like to find a circuit using a Hall effect current sensor to drive a digital microamp meter. The meter would serve as a speed indicator and an "off-on" indicator as well. Can someone point me to a circuit I could adapt to fit this criteria? I have never used a Hall sensor before. Thanks.

 

[Harald Kapp]

Why use a hall circuit if you don't have experience with it?
Get a cheap multimeter with a 10A current range and insert that into the line leading to the motor.

 

[BlinkingLeds]

You could also get a 40-50amps analog or digital panel meter and install it very easily. It would also be allot more accurate than the hall sensor

 

[jfroage]

I am on it. Much easier. Thanks.

 

[BlinkingLeds]

So what will you use?

 

[jfroage]

I found a 0-50 amp meter on Amazon for under $10. (panel mount) I think I can mount the meter in the same plate with the trolling motor plug-in box. This will make for easy access to the trolling motor wires that run to the battery in the back of the boat. The meter I found is analog, but will be okay. I would like to have a digital but the power supply would be a pain to build and to mount. Thanks to all for your thoughts.

 

[BlinkingLeds]

I found a 0-50 amp meter on Amazon for under $10. (panel mount) I think I can mount the meter in the same plate with the trolling motor plug-in box. This will make for easy access to the trolling motor wires that run to the battery in the back of the boat. The meter I found is analog, but will be okay. I would like to have a digital but the power supply would be a pain to build and to mount. Thanks to all for your thoughts.

Ok i also like analog ampmeters but be sure to buy the shunt resitor with it.

 

[BlinkingLeds]

You can still use a digital ampmeter I'm sure you could borrow 12v or 24v (what does your boat has?) from somewhere. But digital meters aren't so reliable that's why i use mostly analog .