JPS60129965A - Reading and writing device for magnetic card - Google Patents

Abstract

PURPOSE:To prevent instantaneously the miswriting on a magnetic card and to prevent the destruction of the data on the card, by stopping instantaneously the supply of the writing energy (application of power supply) to a card reading/ writing device. CONSTITUTION:An instant stop arises by some reason while a magnetic card 1 is read by a card reading/writing device 2, and the voltage of a power supply 3 starts to drop. In such a case, a reset circuit 4 is actuated as soon as the power supply voltage drops lower than the action securing level of a muCOM5. Thus a reset signal is produced to reset the muCOM5 to its initial state. At the same time, a signal is sent to a switch circuit 7 to cut off the circuit 7. As a result, the voltage supply is cut off to the device 2 from the supply 3. Therefore no miswriting is performed to the card 1 although a write mode is set mistakenly by a malfunction of the device 2 since no power is supplied to the device 2. In other words, the data written on the card 1 is never destructed, and protected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic card read/write device that can be used in any device capable of writing data to a magnetic cart.

Structure of the conventional example and its problems FIG. 1 shows a conventional magnetic card read/write device. The configuration of this conventional example will be explained below. In the figure, 1 is a magnetic card, 2 is a manual or motorized automatic card reader/writer, and 3 is the card reader/writer.
A power supply 4 that supplies voltage to the writer 2 and one other element is a seven-node circuit that operates when the operation guaranteed voltage of the microcomputer (hereinafter referred to as μCOM) 6 is exceeded.
A signal (referred to as a reset signal) for setting the μGOM6i to its initial state is generated. 6 indicates input/output means of the μcoMs. The input/output means 6 is for inputting and outputting signals to μcoMs, and may be, for example, a key switch, or may refer to a buffer that converts a signal transmitted from a separate communication line. Here, card read/
It is a buffer that inputs a signal to the writer 2 via μ(30M5) to perform a write operation, displays read card data, or transmits it to other equipment.

Next, the operation of the above conventional example will be explained.

When the power supply 3 is turned on, voltage is applied to the card reader/writer 2 and other blocks. At this time, the reset circuit 4 operates until the power supply voltage reaches μ(IOM 5's guaranteed operation value), and provides a reset signal to μC0M5.In other words, the μCOM seven-node circuit 4 is activated. The period between is held at the initial state and is not in operation state.When the power supply voltage reaches the guaranteed operation value of μC0M5,
The reset circuit 4 becomes inactive, ie stops sending the reset signal. As a result, μCOM5 starts operating normally. Next, writing data to the magnetic card 1 will be explained. Data input via the input/output means 6 by keystroke or transmission is checked by μC0M5 and then sent to the cart 1, . . ., writer 2 as serial data. When the magnetic card 1 is passed through the cart write writer 2, a clock is generated as the cart 1 moves, and data is actually sent from the μC0M6 in synchronization with this clock, and the data is written to the magnetic card 1. It turns out.

However, in the above conventional example, the card read/
Since the power supply is directly connected to the drive l-2, it is assumed that an abnormality occurs in the power supply, for example, a momentary power outage occurs during the writing operation. Reset circuit 4 works normally and μCOM6
There is no problem since it is disabled. However, as the power supply voltage decreases, the logic circuit of Cart ! There is a good chance that the wrong data will be written on the card 1. If the data is uncertain during the writing process, you can try writing again after the momentary power outage ends. If the mote switching circuit that distinguishes between reading, writing, and writing malfunctions during reading operations due to the above reasons, incorrect information will be written to cart 1, resulting in the serious result of destroying the data on card 1. It had the disadvantage of reaching

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned conventional drawbacks, and an object thereof is to provide a magnetic card read/write device that does not perform erroneous writing operations even if there is a momentary power outage during reading operations. It is something to do.

Structure of the Invention In order to achieve the object described in section 2, the present invention provides a card reader/
The writing energy (power supply) supplied to the writer is not supplied in the event of a momentary power outage, which completely prevents erroneous 1 writing onto the magnetic card in the event of a momentary power outage, resulting in the effect that the data on the magnetic cart will not be destroyed. It is something.

Explanation of the example FIG. 2 shows the configuration of an embodiment of the present invention.

This will be explained using FIGS. 3 and 4.

In FIG. 2, numerals 1 to 6 indicate the same items as those in FIG. A switch circuit 7 is inserted between the power supply 3 and the cart lead/writer 2, and is controlled to be turned on and off by the output of the reset circuit 4. Next, the cart data reading operation of the above embodiment will be explained. After the device is set for reading operation by the input/output means 6, the magnetic card 1 is passed through the cart reader/writer 2. The data on the card 1 is read by the card reader/writer 2 and sent to μC0M6. The μCOM 6 processes the data and can display it on a display element or transmit it to other equipment via the input/output means 6.

At this time, in a steady state where the power supply voltage is at the guaranteed operation value of μC0M5, the reset circuit 4 is inactive and no reset signal is issued, so the switch circuit 7 is always in a conductive state, and the voltage of the power supply 3 is applied to the card reader/writer 2. Supplied. If an instantaneous power outage occurs for some reason while the card 1 is being read by the cart reader/writer 2 and the voltage of the power supply 3 begins to drop, the reset circuit occurs as soon as the voltage of the power supply 3 begins to drop below the guaranteed operation value of μCo1t6. 4 is activated and generates a reset signal to return the μCOM6i to its initial state, and at the same time sends a signal to the switch circuit 7, cutting it off.As a result, the voltage is supplied from the power supply 3 to the card reader/writer 2. will be cut off.

As a result, even if, for example, the card reader/writer 2 malfunctions and enters the write mode, no power is supplied, so erroneous writing to the card 1 is unlikely to occur. In other words, the data written on card 1 is protected without being destroyed. Correct reading can then be performed after the power is restored again.

Next, the operations of the reset circuit 4 and the switch circuit 7 will be explained by showing a specific example with reference to FIGS. 3 and 4. 3 is a power supply, 4 is a reset circuit, and 7il''j is a switch circuit.

The AC voltage stepped down by lance 8 is rectified by rectifier 9, smoothed by capacitor 1O, and becomes DC.

This DC voltage vNR enters the voltage stabilizer 11, and the output voltage becomes ■. . is stabilized and supplied to each element of the device. On the other hand, a transistor 12KVi base ([1) whose emitter is connected to voo is given a potential divided by vNR (T) resistors 13 and 14, a resistor 15 is used as a load resistance, and a capacitor 16 is connected to the collector and
0 to form a reset circuit 4. , the output of the reset circuit 4 is connected to the RST terminal and the base resistor 18 of the transistor 17 of the switch circuit element.

Further, the collector of the transistor 17 whose emitter is grounded is connected to the base of another transistor 19, and the collector of the transistor 19 is connected to V. The emitter is ■s at 0
It becomes an output, and the ■5 terminal becomes the power supply to the card reader/writer 2 shown in Fig. 2. A resistor 20 is connected between the base and collector of the transistor 19. Note that 21 is a capacitor, 22 is a diode, and 23 is a resistor.

Next, the operation will be explained with reference to the waveforms shown in FIG.

When the power is turned on at 1-0, the circuit operates as explained above, and by adjusting the voltage division of resistor 13 and resistor 14, VCC is within the guaranteed operation range of μGOM5 (Vcc±α).
The transistor 12 can be kept in the ON state until the voltage reaches . At this time, the R8T terminal is at a high level (H"+), and the waveform indicated by the diagonal line in FIG. 4 is output. At this time, the transistor 17 is "ON", and the transistor 19I-j:
Since it is ``OFF'', no voltage is supplied to the vs terminal. When the voltage further increases and the divided potential of resistors 13 and 14 exceeds vcc, the transistor 12 becomes OFF, the R8T terminal becomes low level ("L"), the transistor 17 becomes 1IOFF, and the transistor 19 becomes ON.
'', and the ■8 voltage is supplied to Cart Lead Like 2 in Figure 2.If the power supply drops due to a momentary power outage, etc., the same principle applies - the rR3T signal becomes H'', and the vs voltage is also supplied. It will be terminated.

In the description of the above embodiment of the present invention, the switch circuit is inserted between the power supply and the cart lead/writer, but the switch may be inserted in the cart lead/writer, for example, and the switch circuit may be inserted between the power supply and the cart lead/writer. Any intention to cut off writing energy in an unstable voltage region is included in the present invention.

As described in the detailed description of the invention, the present invention has a reset circuit that operates when the power supply rises and falls, and the reset signal controls the conduction and cutoff of the switch circuit. Even in the event of a power outage, it is possible to prevent accidents such as data being destroyed due to erroneous writing on magnetic cards, and its industrial efficiency is excellent.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional magnetic cart read/write device, Fig. 2 is a block diagram of a magnetic cart read/write device according to the present invention, and Fig. 3 is a power supply circuit, reset circuit, and switch circuit in the same device. FIG. 4 is an explanatory diagram based on the timing chart of FIG. 3. 1... Magnetic card, 2... Card reader/writer, 3... Power supply, 4... Reset circuit, 5...
... Microcoscipiputer, 6... Input/output means,
7...Switch circuit.

Claims (1)

[Claims] A card reader/writer capable of writing and reading data to and from a magnetic card; a microcomputer that controls the card reader/writer to perform data writing and reading operations; and a power supply voltage that controls the operation of the microcomputer. A magnetic cart read/write circuit comprising a reset circuit that operates when the guaranteed value is exceeded, and a switch circuit that is connected between a power supply and the card reader/writer and controls conduction and cutoff of the power supply current by the output of the reset circuit. Light device.