摘要 |
<p>A drive circuit for controllably driving a heater which is used for maintaining ink in an ink jet printer at a predetermined temperature. A plurality of power sources are installed in the circuit each for supplying a voltage to the heater. The power sources are selectively connected to the heater by a plurality of output transistors and an error amplifier adapted to control switching actions of the output transistors. Diodes are interposed between the respective transistors and the error amplifier to enhance the linearity of the level of the voltage supplied to the heater.</p> |