Using Termistor as Inrush Current Bolcker

[rhnrgn]

Here is the design problem =)

1_i will drive 5V 90ma 16 dc motors from an 5V 1.5A output DC-DC Converter.
2_Each consume 400ma inrush current first 20ms of motion. after they consume 90ma.
3_i need to remove tat inrush current because i need to start them at the same time and 400ma each can be problem.

Here is problem:
1_if i put 40 Ohm at 25C thermistor in series with dc motor that thermister can only decreases its' resistance to 10ohms. Althought it will remove inrush current, that will cause lots of energy loss and slower the dc motor.

2_if i put 5 Ohm at 25C thermistor in series with dc motor that thermisters' resistance is not enough to remove inrush current.

What can you suggest? Is this thermistor suitible?

https://www.digikey.com/product-detail/en/SL05 30001/570-1086-ND/1873489

 

[kam1787]

As I understand it, inrush current is an inherent property of [most] motors, so trying to stop inrush current is self-defeating; maybe the motors will not start, or could be damaged.

BTW a thermistor is a type of resistor whose resistance varies significantly with temperature

 

[FvM]

NTC current limiting works by keeping the thermistor at a relative high temperature. This will cause additional losses in any case, despite of possible problems to find a suitable device. By nature, relative losses will be particularly high for low power loads.

This suggests an active electronic current limiter or soft starter (e.g. MOSFET + RC circuit) instead of a simple NTC.

For a detailed discussion, the load characteristic (minmal motor spin-up current, spin-up time) should be know. By the way, what's the ultimate reason that the motors can't spin-up staggerred?