| 摘要 |
<p>PURPOSE:To give a large amount of currents to load and to reduce the current consumption by providing a switch circuit controlled by a logical circuit and supplying a higher power supply voltage to a drive circuit than to the logical circuit through the switch circuit by means of the logical circuit. CONSTITUTION:When a switch N-channel FET15 is on and a drive N-channel FET10-1 is off, an output channel FET4-1 is turned on. At this time a gate voltage is impressed from an electric power source 7 through the drain source of the switch N-channel FET15 and a resistance 11-1. When the FET15 and the FET10-1 are on, the FET4-1 is off. At this time, a current flows also in the FET10-1 through the resistance 11-1. In order to suppress the current, a control signal from a logic circuit 2, for instance, controls the current through the N-channel FET9. In this case, the FETs15-1-15-n are off to suppress the current consumption during printing or during a period when printing is carried out and the output N-channel FETs4-1-4-n of all bits are off.</p> |
