To get rid of the necessity to buy a tap again corresponding to the current value of the power consumption of a new personal computer since the personal computer has the different current value of power consumption according to difference of makers or models, and also there is the tap, which cannot be used if the maker and the model are different.

The tap of a interlocking type has a relay point of contact 6, which is intervened between a main power distribution wall socket 3 and a sub power distribution wall socket 5, a current detection means 7 to detect the power consumption of the personal computer 2, an amplification means 8, a digital signal conversion means 9, a control means 10, a memory means 11 to make the current value memorize, the memory current value change means 12, which changes the memory current value of a memory means, and a relay 13, which is arranged in between the control means and the relay point of contact, and operates when the current value of the digital signal inputted into the control means is larger than the memory current value memorized by the memory means.