inrush current

Other Hardware General Electronics
1

Hi everyone,

I need some help.

I will start by saying I am no technician.

I am building an electrical Go Kart and I am at a fairly good point.

The circuit is easy given my knowledge:

Two 12V batteries - fuse - tension regulator - two relays 4 switch to invert polarity - two switches (forward motion and backward motion).

My problem is the inrush current.

Is there anything to reduce it, so that the fuses don't burn all the time?

2

Hi,

Is there anything to reduce it, so that the fuses don't burn all the time?

Not much if you are using hard-contact relays.

You need/want a "Soft-Start". With Arduino/ Power FETS etc. you can do that and have speed control.

Some older systems used relays and big resistors to do a 2-stage "Soft Start", shorting out the resistors with yet another relay.

You could add some intentional resistance with big resistance wire.. Or just try 20 feet of #20 wire as a test.

3

Voltage regulator? You should not have the motors powered through a regulator.

The inrush current of your Arduino and other control electronics will be insignificant compared to the normal motor current.

Pololu has an interesting blog post about inrush current related to their excellent regulators.

4

Hi,
Welcome to the forum.

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Thanks.. Tom.. :slight_smile:

5

To be honest I am impressed by the speed of response... :slight_smile:
As I said I'm not a technician
I try to make a pattern but in the coming days for this I will try to ask for help ...
The speed controller is "KKmoon 10-50V/40A/2000W DC Regolatore di Velocità del Motore PWM HHO RC Controllore 12V 24V 36V 40V 50V Regolatore di Velocità "
I will try to change relays with others that support a higher current.
I will also try to be more precise

Thanks really to everyone

Andrea

prova go kart1.zip (883 Bytes)

schema.jpg
schema.jpg2560×1536 945 KB

6

Hi,
Thanks for the diagram.
Ops diag.

schema.jpg
schema.jpg2560×1536 945 KB

Do you only get inrush current when you connect to your battery, or when you start/stop the motor?
If you have the wheels off the ground, does the problem still occur?

What are the specs on the motor?
What size fuse are you using?

Tom... :slight_smile:

7

With high power DC motors its a really good idea to use PWM to control them via H-bridge, then
you can ramp up the drive from zero rather than slam full-voltage onto the motor terminals
instantaneously. The stall torque can be scarily large.