Abstract: A hot-plugging circuit associated with a backplane or motherboard for controlling the rate of application of voltage and current to a non-operating printed-circuit card in the process of being inserted into a backplane connector in a system including other already-operating printed-circuit cards. Each backplane connector has connector contacts of two different lengths. An isolation diode at each connector is connected to two of the longer contacts of the connector and is forward biased by a non-operating printed-circuit card being inserted into that connector. The forward-biased isolation diode triggers a card insertion circuit to recognize that a non-operating printed-circuit card is in the process of being inserted. The card insertion circuit triggers a voltage and current control circuit to ramp up the voltage and current furnished to the non-operating printed circuit.