JPS6345091Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is designed to improve the transmission output strength and
The present invention relates to a signal display circuit that aims to easily display modulation degree and received signal strength.

[Conventional technology]

It is not at all uncommon to install a transmission output strength meter or a modulation factor meter in a wireless communication device, and a received signal strength meter in a wireless receiver. However, in micro-sized communication devices such as handy transceivers, there is no room for adding such a display device, so the actual situation is that it is not used. Of these, the reception strength does not have much of a problem because the reception status can be confirmed by the reception sound even if the strength is not displayed on the meter, but a drop in transmission output or a state where transmission is impossible cannot be determined without an output meter, so it is difficult to respond. Until then, there is uncertainty as to whether transmission is actually occurring. Furthermore, even if radio waves are emitted, if modulation is not performed due to a malfunction in the microphone or other modulation circuit, communication may become impossible.

[Problem that the invention attempts to solve]

As part of the countermeasures, the present applicant has previously applied for the invention of Utility Model Application Publication No. 18361 of 1982, ``FM transmitter circuit with modulation instruction superimposed on output indicator''. The purpose of this is to detect the modulation status of simple FM transmitters without a modulation indicator by superimposing a modulation signal on the output indicator, thereby preventing communication failures due to failures in the modulation circuit. In an AM transmitter, the change in carrier amplitude due to modulation can be seen as a change in the output meter indication, but in an FM transmitter, the carrier amplitude is constant regardless of the presence or absence of modulation, so the output meter indication indicates a change in the modulation. Since the situation is unknown, this is a countermeasure, as stated in the detailed explanation section of the invention in the specification of the same application: ``In this invention, the intensity of the modulation signal applied to the FM modulator is detected, and this is output as shown in Figure 1. indicator 9
The information is displayed superimposed on the instruction, and this makes it convenient to know the transmission output and modulation state at the same time. This is especially convenient for small portable devices where there is no room to add an extra display to the narrow panel surface. It is clear from the statement, ``. However, as portable communication devices have become more and more miniaturized since then, there is no room to add even an output meter, and many of them are omitted.

[Means to solve the problem]

Two sets of transistors have their emitters grounded via light emitting diodes of different colors, one base is connected to an attenuation circuit from an antenna circuit, and the other is connected to the base via a diode, and the base of the other transistor is connected from a modulation circuit to an attenuation circuit. is input to the base via a diode, and the modulation operation and transmission output are displayed by light emission.For the receiving circuit, a part of the output of the receiving circuit is applied to the base of one of the transistors through the diode, and the receiving status is also monitored. This is a signal display device.

〔Example〕

An embodiment of the present invention will be explained with reference to FIG. A part of the transmitted carrier wave from the antenna circuit is rectified by the first diode _D1 , its DC output is applied to the base B of the first transistor _Q1 , and its collector current causes the first diode connected between the emitter E and the ground to be means for lighting a light-emitting diode LD ₁ of , rectifying a part of the modulation signal with a second diode D ₂ and applying its DC output to the base B of a second transistor Q ₂ ;
A second light emitting diode LD ₂ whose collector current emits light in a different color from that of the first light emitting diode is connected between the emitter E and the ground to turn on the base of the first or second transistor ( In Figure 1, for convenience, the base B on the second transistor _Q2 side)
This is a signal display circuit of a communication device that applies a voltage approximately proportional to the received signal strength to the signal through a resistor R or a backflow prevention diode _D3 . The operation of this circuit is to switch the light emitting diode LD ₁ depending on the size of the transmission output.
blinks, and the light emitting diode LD ₂ blinks in response to the modulated sound. LD ₁ and LD ₂ emit different colors, such as green and red, so you can see with a single glance which output or modulation is operating and which is not. Furthermore, during reception, it is possible to roughly determine the reception strength. As is well known, the light emitting diodes LD ₁ and LD ₂ used here are extremely small and provide high brightness with low power consumption, and are easy to install in ultra-compact communication devices, making them extremely convenient especially for use in dark places. It is. In Fig. 1, the light emitting diode is placed in series with the emitter E of the transistor, but for convenience, it can also be placed in series with the collector C, as the utilization of the collector current is almost _the same, so there is no problem. This is for bias. Furthermore, the above-mentioned light emitting diode
By housing LD ₁ and LD ₂ in the same package as shown in FIG. 2, installation space can be further saved.

[Effect of idea]

In addition to the practical effects of the ultra-compact output/modulation/reception signal display circuit of this invention, by mixing the emitted light colors, the combined emitted light color changes slightly at the same time as the emitted light intensity changes, so it is possible to simply output In addition to knowing the intensity and degree of modulation, it is possible to add fashion properties that involve color changes, resulting in even better effects.

[Brief explanation of the drawing]

FIG. 1 is a signal display circuit diagram showing one embodiment of the present invention, and FIG. 2 is an embodiment in which two light emitting diodes are housed in the same package. D ₁ , D ₂ , D ₃ , D ₄ ...Diode, LD ₁ , LD ₂ ,
...Light-emitting diode, Q ₁ , Q ₂ ...Transistor.

Claims (1)

[Claims for Utility Model Registration] 1. Part of the transmission carrier wave of the transmission output circuit is rectified by a first diode, its DC output is applied to the base of the first transistor, and the collector current causes the first light emitting diode to be rectified. a part of the modulated signal is rectified by a second light emitting diode, the DC output thereof is applied to the base of the second transistor, and the collector current causes the emitted light to emit a color different from that of the first light emitting diode. means for lighting a second light emitting diode;
A signal display circuit for a wireless communication device, characterized in that a voltage approximately proportional to the strength of a received signal is applied to the base of a transistor through a resistor or a backflow prevention diode. 2. In the preceding paragraph, the wireless communication device according to claim 1 of the utility model registration claim is characterized in that the first light emitting diode and the second diode having a different emission color are housed in the same package. Signal display circuit.