| 摘要 |
PURPOSE:To reduce the number of component parts of the circuit and simplify the structure of the circuit by a method wherein a constant-current control for a plurality of dot-pin driving solenoids is conducted by using a single controlling transistor. CONSTITUTION:The plurality of dot-pin driving solenoids 111, 112...11n, a load solenoid 110 having a load of characteristics equivalent to those of the driving solenoids and a plurality of output transistors 121, 122...12n, 120 for respectively controlling the power supply for the solenoids are provided. By using the single controlling transistor 17, the amount of current passing through the load 110 is detected and each of the output transistors 121-120 is controlled, whereby the currents passing through the load 110 and the solenoids 111...11n are controlled to be constant. |
