Most electronics devices nowadays have an on/off button that doesn’t really turn on or off, but simply toggles between active mode and standby. If the power goes off and then comes back on, the unit usually comes on in standby mode.

I would really like to be able to change this behaviour and have a device come on in active mode whenever power is present. My question is whether this is controlled by a standard chip or circuit that is the same across different devices, and what would be involved in making such a modification. Would this be a difficult thing to do? I know enough electronics to assemble kits and make certain modifications, but not enough to design my own circuits.