JPS60260359A - Power source supply system - Google Patents

Abstract

PURPOSE:To eliminate the necessity for considering a peak current with respect to the capacity of a power source board, in supplying a power source in the power source supply system of a thermal printer, by supplying the power source through a large capacity condenser. CONSTITUTION:For example, in supplying the power of DC 24V to a thermal printer 2 from a power source board 1, a large capacity condenser C is preliminarily connected to a power source power input part while an inrush current preventing circuit 3 for preventing an inrush current at the closing time of a power source is connected thereto. Therefore, an impact like large current at the time of printing is caught by the condenser C and the consideration of a peak current becomes unnecessary with respect to the capacity of the power source board 1 and miniaturization can be achieved. The inrush current preventing circuit 3 prevents the inrush current on the basis of such a mechanism that no current is flowed to a transistor Tr because voltages at both terminals of the condenser C are low at the closing time of the power source board 1 and a relay RL is not operated and a contact rl is opened to insert a resistor R into the condenser C in series.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in the power supply system of a thermal printer used in electronic equipment 1 communication equipment and the like.

Thermal printers are easy to handle because they are completely dry recording systems that require development and fixing, and because they do not require mechanical movement during printing, they are low-noise and are often used in electronic equipment and communication equipment. Therefore, it is desired that the power supply panel be made smaller.

[Conventional technology]

Thermal printers require a large amount of current to flow through the thermal recording head during printing.

In order to meet this demand, conventionally a power supply panel that can supply this peak current has been used.

[Problem that the invention seeks to solve]

Conventionally, as explained above (because a power supply board that can also supply peak current is used), a large capacity is required and the power supply board becomes large.

[Means for solving problems]

The above problems are solved by the power supply system of the present invention, which connects a large capacity capacitor to the power input of a thermal printer.

[Effect]

As mentioned above, when a large capacity capacitor is connected to the power supply input, when a peak current is required, this is supplemented by discharging the capacitor, so there is no need to consider the peak current as the capacity of the power supply board, and the size can be reduced.

〔Example〕

FIG. 1 is a block diagram of a power supply system according to an embodiment of the present invention.

In the figure, 1 is a power supply panel that supplies 24V DC power, for example.
2 is a thermal printer, 3 is an inrush current prevention circuit, C is a large capacitor, R', R1, R2 are resistors, RL is a relay, RL is a contact of relay RL, Dl is a Zener diode, D2 is a diode, Tr indicates a transistor.

In Fig. 1, in order to supply power from the power panel 1 to the thermal printer 2, for example, I)C24, a large capacity capacitor C is connected to the power input section of the thermal printer 2, and the power is turned on. In this case, an inrush current prevention circuit 3 is connected to prevent inrush current.

By connecting a large-capacity capacitor C, the impressively large current during printing by the thermal printer 2 is captured by the capacitor C, so the capacity M of the power supply panel 1 can be made smaller as there is no need to consider peak current selection. I can do it.

However, when the power is turned on, a large current flows from the power supply panel 1 to charge the capacitor C, so a rush current prevention circuit 3 is provided to protect the power supply panel 1.

In this inrush current prevention circuit 3, when the power is turned on, the voltage across the condenser C is low, so no current flows through the transistor Tr, the relay RL does not operate, the contact r1 is in a solid line state, and the capacitor・A resistor R is inserted in series with C to prevent inrush current.

When capacitor C is charged, the voltage across both ends increases, current flows through transistor Tr, operates relay RL, and contacts rl
becomes the state shown by the dotted line, shorting the resistor R and returning to the normal state.

〔Effect of the invention〕

As explained in detail above, according to the present invention, the capacity of the power supply panel can be reduced and the size of the power supply panel can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a power supply system according to an embodiment of the present invention. In the figure. ■ is a power supply panel, 2 is a thermal printer, 3 is an inrush current prevention circuit, C is a large capacitor, R, R1, R2 are resistors, DI is a Zener diode, D2 is a diode, Tr is a transistor, RL is a Relay, rl indicates the contact point of relay RL. Agent Patent Attorney Hiroshi Matsuoka Shibusan L-1111111 --J

Claims (1)

[Claims] A power supply method characterized in that when power is supplied to a thermal printer, power is supplied through a large-capacity capacitor.