DRIVING CIRCUIT FOR HEAT-SENSITIVE RECORDER

摘要

PURPOSE:To provide a driving circuit capable of facilitating group energizing voltage setting and maintenance work and adapted to determine the group energizing voltage with a variable resistor by connecting a particular circuit to the control input terminals of group energizing switching elements or group energizing switching circuit. CONSTITUTION:A group energizing switching circuit for applying a heat generation energizing voltage to terminals S6 and S7 are constituted by the combinations of NPN transistors 9-1-9-3 and NPN transistors 10-1-10-3, respectively. A cascade circuit of a current limiting resistor 12 and a variable resistor 13 is connected to the control input terminal of the group energizing switching circuit. A regulated power supply circuit 11 is connected to the resistor 12 in order to maintain the voltage (current) applied to the resistor 12 at a fixed level. When the group selection signal input terminal S1 is grounded, a sum of a voltage Vb at a point (b) and the voltage drop VD of a diode 6-1 is generated at the base of the transistor 9-1, while the remainder of subtraction of a voltage drop VBP between the base and the emitter of the transistor from the voltage Vb is generated at the emitter of the transistor 10-1. The applied voltage can be regulated with the variable resistor 13.