| 摘要 |
PURPOSE:To elevate line voltage with the rise of an ambient temperature by connecting the parallel circuit of a thermistor and a resistor and a series circuit with a constant-voltage element between a connecting section with a power supply at the secondary side of a diode and the base of a controlling transistor. CONSTITUTION:When the potential of output rises, the rise is transmitted to the base of the controlling transistor 4 and the transistor is at ON, a feed transistor 3 is at OFF, and oscillation is stopped temporarily, thus stopping the supply of power to output. When the potential of output drops, on the other hand, oscillation is strengthened. The potential hardly has relation to the variation of battery 1, and determined by voltage generated in the series circuit of the Zener diode 11 and the resistor means 15. When the ambient temperature rises, voltage generated at a terminal 16 at the secondary side also drops because the resistance value of the thermistor 12 drops and voltage Vc drops while being also related to a resistor 17. Accordingly, voltage is changed positively by temperature, and characteristics proper to a thermal printer can be given. |
