JPS6010136Y2 - portable electronics - Google Patents

Description

[Detailed description of the invention] This invention relates to portable electronic equipment, such as radio equipment, that uses dry batteries or storage batteries as a power source, and is capable of indicating a drop in power supply voltage and the usable time of the power supply. be.

Conventionally, in this type of electronic equipment, a drop in power supply voltage has not been indicated, or even if it has been indicated, it has been indicated by a meter, brightness of light, etc.

Therefore, if the radio you are carrying is set in such a way that it cannot be seen or if you cannot attract attention,
The drawback is that it causes wave damage to the storage battery used as a power source.

The present invention eliminates these drawbacks.

One embodiment will be described below with reference to the accompanying drawings.

In Figure 1, 1 is a breath talk switch for switching between reception and transmission, 2 is an antenna, 3 is a reception signal processing circuit, 4 is an audio amplification circuit, 5 is a speaker, 6 is a transmitting unit, and 7 is a dry cell or storage battery. 8 is a power switch; 9 is the breath talk switch 1;
a switch circuit 10 that is turned on when switched to the transmission mode (terminal TX side) and supplies power supply voltage to the transmission unit 6;
．． 11 sets the breath talk switch 1 to receive mode (terminal R
12 is a low voltage detection and alarm signal generation section, which turns on the power supply voltage when switched to the X side) and supplies the power supply voltage to the reception signal processing circuit 3 and the audio amplification circuit 4, respectively; 12 is a low voltage detection and alarm signal generation section; is detected, and when the power supply voltage drops below a predetermined value, low pressure detection signal A and low pressure alarm signal B1 are generated.
Each outputs a low pressure alarm signal C.

Reference numeral 13 denotes a light emitting diode connected to the output terminal of the low pressure alarm signal B of the low pressure detection and alarm signal generation section 12.

14 is an OR gate with one input terminal connected to the terminal RX and the other input terminal connected to the output terminal of the low voltage detection signal A; the output terminal is connected to the switch circuit 11;
Control 1.

Next, to briefly explain its operation, the power switch 8 is closed, and in the normal reception state, the breath talk switch 1 is connected to the terminal RX side, so the switch circuit 10 and the OR
The switch circuit 11 is turned on through the gate 14, and power is supplied to the received signal processing circuit 3 and the audio amplifier 4.

Therefore, the received signal from the antenna 2 passes through the received signal processing circuit 3 and the audio amplification circuit 4 and is output from the speaker 5.

On the other hand, when the breath talk switch 1 is connected to the terminal TX side, the switch circuit 9 and the low pressure detection and alarm signal generation section 1
2 is turned on, the transmitting unit 6 operates, and the light emitting diode 13 lights up to display a transmission.

Then, after a certain period of use, when the voltage of the power supply 7 decreases and reaches the preset minimum voltage, low pressure detection and alarm signal generator 12 outputs low pressure detection signal A, and at the same time low pressure alarm signal B1 low pressure alarm signal is output. C is output, the light emitting diode 13 blinks due to the low pressure alarm signal B, and on the other hand, the switch circuit 11 is turned on due to the low pressure detection signal A, power is supplied to the audio amplification circuit 4, and the low pressure detection and alarm signal generation section 12 A low pressure alarm signal C is outputted from the speaker 5 through the audio amplification circuit 4.

In this way, according to the configuration shown in FIG. 1, the light emitting diode 13 blinks and the speaker 5 issues an alarm to notify that the power source 7 is depleted, so that damage to the storage battery etc. due to overdischarge can be reliably prevented. .

FIG. 2 shows a specific example of the low pressure detection and alarm signal generating section 12 shown in FIG. 1, and its detailed operation will be explained below with reference to FIGS. 3 to 5.

In FIG. 2, when a power supply voltage is supplied in a transmitting state, the voltage is divided by a resistor 21 and a variable resistor 22 and applied to lambda diodes 23 and 24, respectively.

As shown in FIG. 3, the lambda diodes 23 and 24 have a lambda-shaped negative resistance characteristic in which a current IP flows when the applied voltage Vin becomes a certain value 9 or less. By adjusting and setting the voltage appropriately, when the supply voltage is high, one lambda diode 23 is turned off, so that the transistor 2
5 is also turned off, and the transistor 26 is turned on, so that low pressure alarm signals B and C are outputted from its emitter, and the light emitting diode 13 is lit by the low pressure alarm signal B to indicate the transmission state.

At this time, since the lambda diode 24 is off, the transistor 28 is turned off, and since the transistor 29 is turned on, the collector output of the low voltage detection signal A becomes low level, so that the switch circuit 11 It remains closed, and power is not supplied to the audio amplification circuit 4.

When the power supply voltage drops below a predetermined value, the lambda diode 23 becomes conductive, the transistor 25 turns on, and the transistor 26 turns off, and the light emitting diode 1
3 goes out.

From this point on, the capacitor 27 is discharged, the lambda diode 23 is turned off again, the transistor 25 is turned off, and the transistor 26 is turned on, so that the light emitting diode 13 is lit again.

Thereafter, the above operation is repeated and the light emitting diode 13 blinks.

On the other hand, at this time, the other lambda diode 24 is also turned on, which turns on the transistor 28, and turns off the transistor 29, so that the low voltage detection signal A becomes high level, the switch circuit 11 is closed, and power is supplied to the audio amplification circuit 4. The low pressure alarm signal C passes through the audio amplification circuit 4 and generates an intermittent sound from the speaker 5.

At this time, in the low pressure detection/alarm signal generation section 12, as shown in FIG. You can know how long you can talk after the low pressure alarm is displayed.

FIG. 5 shows a timing chart of low pressure alarm/display.

Figure 5a shows the position of the breathtalk switch 1; Figure 5c shows the position of the breathtalk switch 1 in the switch circuit 1.
The reception on signal E1 applied to 0.11 shows the transmission on signal applied to the switch circuit 9, respectively.

In addition, d, e, and f in FIG. 5 indicate the low pressure detection signal A1 and the low pressure alarm signal B from the low pressure detection/alarm signal generation section 12, respectively.
y indicates C.

The configuration of FIG. 2 and the low pressure alarm signal B of FIG.

As is clear from C, as the voltage drop of the power supply 7 increases, the blinking of the light emitting diode 13 and the intermittent sound from the speaker 5 become faster, so this operation can be used to find out the usable time of the radio. can also be applied.

As explained above, according to the present invention, it is possible to check the remaining power level of the power supply by checking the appearance of the display section whose intermittent cycle changes continuously depending on the power supply voltage due to a lambda diode, so that the power supply voltage decrease can be confirmed by checking the display section whose intermittent period changes continuously depending on the power supply voltage. Damage caused by over-discharge can be reliably prevented.

[Brief explanation of drawings]

Figure 1 is a system diagram of a portable electronic device in an example of the present invention, Figure 2 is a specific circuit diagram of the low voltage detection/alarm signal generation section in Figure 1, and Figure 3 is a voltage-current characteristic diagram of a lambda diode. , FIG. 4 is a diagram showing the setting conditions of the low pressure detection/alarm signal generation section, and FIG. 5 is a timing chart for explaining the operation of the present invention. 1... Breath talk switch, 2...
Antenna, 3... Receiving/signal processing circuit, 4...
...Audio amplification circuit, 5...Speaker, 6.
...Transmission unit, 7...DC power supply, 8
...Power switch, 9,10°11...
-Switch circuit, 12...Low pressure detection/alarm signal generation section, 13...Light emitting diode, 14...
...OR gate.

Claims (1)

[Scope of utility model registration request] a lambda diode having lambda-shaped negative resistance characteristics;
Detecting that the power supply voltage has fallen below a predetermined value by turning on and off the lambda diode, and changing the on/off cycle continuously in response to the power supply voltage over a certain range of the reduced power supply voltage. 1. A portable electronic device comprising: a switch circuit that controls the display; and a display section that is controlled by the switch circuit.