Current limiting for inrush current

inrush current limiting

Hi guys, it's been a while since i last posted. How's everyone? I currently have a problem which i hope you guys can comment.

I have an application where i have a simple DC motor running at 24V (turned on for only 1 second). This motor switches a small load from A to B. According to specs i am to set my power supply at a current limit of 300mA. But i suspect due to inrush current (when the motor is turned on with load), my power supply trips (OCP). The motor is suppose to run at an operating current below 300mA.

Is there any device where i can have my current limit initially higher (say 450mA) and after a couple of ms change back to a lower value 300mA?

The reason i can't set with my power supply is because it's remotely controlled through serial port and the command's response time may not be fast enough.

Any ideas?

Added after 41 minutes:

Hi, i've done some reading and i think what i actually need is a inrush current control circuit (surge limiter).

The power rating i need is quite small but the problem is i need something which is of the shelf. Can anyone recommend any suppliers who such things? Thanks.

Hello,

A simple "surge limiter" often used in power electronics (e. g. VFD) is a series resistor shorted by a relay after a short delay. In your case, you could use a MOSFET switch with an RC delay circuit at the gate. As an advantage, this circuit would cause a very low voltage drop in normal operation.

A more simple option may be to ramp the motor voltage, respectively increase it in steps. At best, you should have a supply that has current limiting instead of overcurrent trip.

Regards,
Frank

what is Current limiting for inrush current