DC Power Supply Turn On Current Surge

[psyhunter2001]

Hi,
I have been told that in some cases when you slowly turn on a DC power supply (ex. Instek GPC-3030D) there are certain points where there will be a slight instant surge of current and drop of voltage while you slowly change the voltage to the desired voltage. Is this true? And if it is what causes this?
Thanks.

 

[hkBattousai]

I thought for it for a minute and I say there is no reason for a current surge.
But there may be a high voltage ripple, if you change voltage value very fast; though it depends on the circuit design of the power supply.

 

[eem2am]

it is charging of bus capacitors