Electrification detection device null for switching power supply

摘要

PURPOSE: To obtain a simple current conduction detector, wherein the switching signals from a switching-signal generating circuit are counted with a counter, and the conducting state of a switching power supply can be detected based on the counted value. ;CONSTITUTION: When the switching signals are f applied on a switching element S from a switching-signal generating circuit 1, the switching power supply in correspondence with the switching time is supplied on a thermal head T. The switching signals are also supplied into a counter C, and counting is performed. The counted value is the number of switchings of the signals. The increase and decrease in number of switchings per unit time correspond to the increase and decrease in an amount of conduction supplied to the head T. Therefore, the amount of conduction to the head T can be grasped based on the number of switching times. Thus, not only the presence or absence of the current conduction to the head T but also the amount of conduction can be detected.;COPYRIGHT: (C)1995,JPO