Techniques and systems whereby operation of andor access to particular features of an electronic device may be controlled after the device has left the control of the manufacturer are provided. One method includes receiving, by a mediator device of a mediator, a second share SKG2 from an owner device, wherein a first share SKG1 is provided to a member device of a member of a group by the owner device. The expansion card includes an edge connector, a number of first sockets exposed through the first opening, and an expansion socket unit. In this inputoutput channel capacity format, dc offset, distortion, and noise all are temperature independent. Data are transmitted non-electrically between the high voltage unit and the low voltage unit. The laser pulses provide a trigger signal to enable recording the time of flight in the atom probe.