JPS6139741A - Electromagnetic interface system - Google Patents

Abstract

PURPOSE:To transfer data from a slave set to a master set without almost using a power supply of the slave set by intermitting a closed circuit comprising a coil of the slave set with a switch to detect that the coil impedance of the master set side is changed. CONSTITUTION:A drive circuit 44 consists of a buffer amplifier or the like and a power supply voltage VDD excites a coil 42. Further, a clock pulse outputted from an oscillator 46 is inputted to an AND circuit 47. The AND circuit 47 receives output data from the master set 41 itself to the slave set 31, the switch 43 is intermitted by the result of logical operation, the drive circuit 44 is actuated to excite the coil 42. Moreover, a detection circuit 48 detecting a potential change in response to the impedance change of the coil 42 is connected to a resistor 45 at the side of the coil 42, and a detection signal of the detection circuit 48 is transmitted to the master set 41 itself from the slave set 31 as data via an inverter 49.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electromagnetic interface for performing electromagnetic data transmission between two electronic devices.

[Prior art and its problems]

Conventionally, electromagnetic interfaces have been used to perform electromagnetic data transmission using coils installed in each of a small portable electronic device, such as a pocket computer, and a small desktop electronic device, such as a personal computer. It is being Figure 4 shows an outline of such a system as a whole.
interfaces (referred to as 110J in the figure) 211 for data input/output control are provided at corresponding positions.

FIG. 5 shows the electromagnetic interface 11"l'.

This shows the 2110 circuit configuration, from slave unit 1'l to base unit 2.
1, the output data is sent to the interface 111 of the handset 1''1 by a switch 12tfL composed of 0MO8, etc. This switch 12 performs an intermittent operation according to the sent data. It is connected in series with the coil 13 and the drive circuit I4 for this coil.The drive circuit 14 is composed of, for example, a Bazza amplifier, and when the switch 12 is in the closed state, the power supply voltage The coil 137 is energized and the output data of the slave unit 11 is transmitted to the base unit 21.

Further, when data is input from the base unit 21 to the slave unit 11, the input data received by the coil 13 at the interface JJJ of the slave unit 11 is sent to the slave unit 11 main body.

The above has described the interface 111 of the slave unit 11, but the same applies to the interface 211 of the base unit 21, which is composed of a coil 22, a drive circuit 23, a switch 24, etc., and inputs and outputs data to and from the slave unit 11. Do the following.

However, both the slave device IZ and the parent device 21 have drive circuits, and the slave device 11 in particular usually uses a small-capacity battery as its power source. Therefore, there is a drawback that the battery is consumed rapidly, especially when data is output to the base unit 2I, and its lifespan is extremely short.

[Purpose of the invention]

This invention was made in view of the above circumstances,
The purpose is to provide a Monbetsu electromagnetic interface that can transmit data from a slave unit to a base unit without using the power supply of the slave unit.

[Key points of the invention]

This invention detects changes in the impedance of the coil on the parent device side by switching on and off the closed circuit consisting of the coil of the child device, and transmits data from the child device to the parent device. It is.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows its circuit configuration. In the interface 311 of the handset 31, a switch 32 and a coil 33, which perform an intermittent operation according to output data, form a closed circuit. Both ends of 320 are also connected to the ground terminal and data input terminal of the main body of handset 31, respectively. On the other hand, in the interface 411 of the parent f2J4t, a coil 42 corresponding to the coil 33, a switch 43, a drive mill 44 of the coil 42, and a resistor 45 are arranged to form a closed circuit. The driving mill@44 is composed of a buffer 7 amplifier and the like, and excites the coil 42 with the power supply voltage VDD. Further, the clock pulse output from the oscillator 46 is input to an AND circuit 47. This AND circuit 47
The output data from the main body of the master device 41 to the child tHsI is also inputted, and according to the logical operation result, the switch 43 is turned on and off, the drive circuit 44 is operated, and the coil 42 is excited. Furthermore, a detection circuit 48 is connected to the coil 42 side of the resistor 45, which detects a change in potential according to a change in impedance of the coil 42.
The detection signal of this detection circuit 4B is sent to the main unit 41 via the inverter 49 as data of the child m31.

Next, the operation of the above embodiment will be explained with reference to the timing charts of FIG. 82 and FIG.

FIG. 2 shows the timing of the signals of each part of the interface 411 of the main device 41 when sending a booter from the main device 41 to the slave device 3Z. A lock pulse is input as shown in . Also, in this AND circuit 47, as shown in FIG.
When the data "JOllO", which is the time per bit for three clock pulses as shown in FIG. A data signal as shown in q is output.Then, the switch 43 is turned on and off according to this data signal, the coil 42 is excited by the drive circuit 44, and the interface 311 of the child 831 is turned on and off.
A data signal comes to be inputted to the main body of the handset 31 via the coil 33.

Next, the operation timing when transmitting data from the handset 31 to the base unit 41 will be explained with reference to FIG.
1 outputs data to the base unit 41, for example, when data rlolloJ as shown in FIG. 3(1) is input to the switch 32 of the interface section 311 of the slave unit 31, this switch Intermittent operation is performed according to the data. Here, in the interface 411 of the main unit 41, a clock pulse is inputted from the oscillator 46 to the AND circuit wI47, and a signal at the rtJ level is always inputted from the main unit 41 as shown in FIG.
With these two inputs, the AND circuit 41'' is activated as shown in FIG.
A clock pulse is output as shown in q, and the resistor 45'1
The coil 42t is energized through the coil 42t. The detection circuit 48 detects the potential level of this coil 42, and this potential level is determined by the interface 31 of the slave device 31.
It changes depending on whether the first switch 32 is opened or closed. That is, when switch 32 is in the open state, coil 42
Almost no electromotive force transmitted to the coil 3S is consumed. However, when the switch 32 is in the closed state, the load of the coil 42 on the coil 33 becomes large, and the potential level detected by the detection circuit 48 decreases. Therefore, when the switch 32 is opened and closed like the data "1O11O" shown in the third part, the data shown in FIG.
By the output of the AND circuit 47 shown in C), the detection circuit 4
8 detects a voltage signal as shown in FIG. Therefore, by setting a specific threshold value TH in the detection circuit 48, and extracting the signal exceeding this threshold value VTR as a horizontal signal and passing it through the inverter 49t, as shown in FIG. This makes it possible to detect output data r10110J.

Switch 32 of the interface 311 of the handset 31
Since it is configured by the CMO 8, the power consumption required for opening and closing the switch 32 is extremely small. Therefore, the slave device 31 can transmit data to the master device 41 by simply opening and closing the switch 32 without consuming much power.

Note that the handset 31 was simply described as a portable small electronic device such as a Kerato computer, but as in the example above, the power consumption is small, so it can be used for bank cash. It is also conceivable that the present invention could be applied to IC cards used in cards, etc., and compact electronic calculators that use card heat.

〔Effect of the invention〕

As described above, according to the present invention, data can be transferred from the slave unit to the base unit without using much of the power supply of the slave unit, and the battery used as the power source for the slave unit can have a short lifespan. The length of the (2 items)

can be done.

[Brief explanation of the drawing]

Figures 1 to 3 show examples of rice sprouting and sprouting.
Figure 1 is a circuit configuration diagram, Figure 2 is a timing diagram showing each signal waveform when outputting data from the master unit, and Figure 3 shows the signal processing status when outputting data from the slave unit. Timing chart, Figure 4 is a diagram showing the outline of the entire system, Figure 5
The figure is a diagram showing a conventional electromagnetic interface circuit configuration. 11.31...Slave device, 21.41...Main device, 111
゜21V, 31'l, 411...interface,
12.24, 32.43...Switch, I J,
22゜33.42...Coil, 14,23.44...
- Drive circuit, 46... oscillator, 48... detection circuit.

Claims (1)

[Claims] In an electromagnetic interface that performs electromagnetic data transmission between a first electronic device and a second electronic device using coils provided respectively, excitation means for exciting the coil of the second electronic device at a predetermined frequency; a control means for controlling switching between short-circuiting and non-shorting of the coil of the first electronic device according to output data to the second electronic device, and a change in impedance of the coil of the second electronic device in the excited state by this control; An electromagnetic interface system comprising: detection means for detecting the output data from the output data.