JPS5820938Y2 - meter device - Google Patents

Description

[Detailed Description of the Invention] This invention is an attempt to make it possible to accurately check the state of battery consumption in a battery operated device such as a radio receiver.

For example, in a radio receiver, a single meter can display the received signal level (input electric field level) and check the battery consumption state.

FIG. 1 shows a conventional example of such a circuit, where 1 is a display meter, which is of the reverse swing type, that is, the second
As shown in the figure, when the current flowing through the meter 1 is small, the pointer 1N swings to the right, and when the current is large, the pointer 1N swings to the left.

The meter 1 has a scale 1S indicating the received signal level from left to right, and a mark 1M indicating that the battery has sufficient remaining power on the left side.

Further, switch 2 is normally connected to the state shown in the figure, but when pressed, the switch is switched in the opposite direction to that shown in the figure. 5 is a power switch; 6
is a battery that serves as a power source.

Since the AGC voltage changes with respect to the received signal level, for example, as shown in FIG. 3, this AGC voltage is supplied to the base of the transistor 3.

Therefore, since the AGC voltage is normally supplied to the meter 1 through the transistor 3 and further through the switch 2, the pointer 1N of the meter 1 swings in accordance with the received signal level, so that the received signal level can be determined.

On the other hand, when the switch 2 is pressed, the voltage of the battery 6 is supplied to the meter 1 through the resistor 4 and the switch 2.

When the voltage of the battery 6 is high, the current of the meter 1 is large and the pointer 1N is located at the mark 1M, indicating that the remaining capacity of the battery 6 is sufficient.

However, in such a circuit, 1 is used as switch 2.
Since a bush switch with two circuit contacts is required, the cost increases.

In view of these points, this invention aims to make it possible to accurately check the state of battery consumption and to reduce costs.

An example of this will be explained below.

In FIG. 4, the AGC voltage is supplied to the base of the transistor 3, its collector is connected to the power switch 5, its emitter is connected to the hot side 1H of the meter 1,
The cold side 1C of the meter 1 is grounded through a resistor 7.

Further, a normally open bushing switch 2, a resistor 11, and a diode 12 are connected in series between the switch 5 and the ground, and the connection point between the resistor 11 and the diode 12 is connected to the hot side of the meter 1. 1H, and the connection point between the switch 2 and the resistor 11 is connected to the cold side 1C of the meter 1 through the resistor 4.

In this case, the emitter potential VE of the transistor 3 when the switch 2 is off is set to be lower than the threshold level (forward voltage drop) VTH of the diode 12.

Further, as shown in FIG. 5, the mark 1M is placed on the right side.

According to this configuration, the switch 2 is normally off, and since VE<VTH, the diode 12 is off.

Therefore, the AGC voltage is supplied to the meter 1 through the transistor 3, and the received signal level is displayed on the meter 1.

On the other hand, when the switch 2 is turned on, the diode 12 maintains a constant voltage regardless of the voltage of the battery 6.
□ is supplied to the hot side 1H of the meter 1, and the voltage of the battery 6 is divided by the resistors 4 and 7, resulting in the divided voltage ■.

is supplied to the cold side 1C of the meter 1.

Therefore, the meter 1 will swing depending on the difference voltage between the voltages VTR and VD.

In this case, if the values of the resistors 4 and 7 are selected in advance so that VTH>Vo, then when the voltage of the battery 6 is high, the divided voltage VD is high, and the voltage .

Since the difference voltage between H and VD becomes small, pointer 1 of meter 1
N is located at mark 1M, indicating that the battery 6 has sufficient remaining power.

Also, when the voltage of the battery 6 decreases, the voltage VD decreases and the voltage difference between the voltages VT) and VD increases, so the pointer I
N will be able to swing to the left.

Therefore, the consumption state of the battery 6 can be checked. Thus, according to this invention, the received signal level can be displayed using a single meter 1, and the state of consumption of the battery 6 can be checked.

However, in that case, the switch 2 may be a simple on/off switch, so the cost can be reduced compared to the case of a changeover switch with one circuit and two contacts (although the number of elements 11 and 12 increases).

Furthermore, the switch 2 can be made smaller and the space factor can also be improved.

Further, when checking the battery 6, the diode 12 causes the hot side 1H of the meter 1 to have a voltage V.

Since it is clamped to H, A is applied to the base of transistor 3.
A GC voltage may be supplied, that is, it may be in a tuned state, and there is no need to detune it each time.

Further, even when the received signal level is high and the voltage of the battery 6 is sufficient, the pointer 1N of the meter 1 swings in the same direction (leftward), so it is convenient to use.

Furthermore, as shown in FIG. 6, for example, a light 13 that illuminates the dial display surface etc. can be connected, and in this case, it can also be used as a switch for the light 13, resulting in further cost reduction. can.

In the above description, if the AGC voltage is not affected by fluctuations in the voltage of the battery 6 and the battery 6 can be checked in the detuned state, the elements 11 and 12 are unnecessary.

It can also be operated, for example, as a recording level meter in a tape recorder.

[Brief explanation of drawings]

Figure 1 is a conventional connection diagram, Figure 2 is a front view of the meter,
FIG. 3 is a characteristic diagram of AGC voltage, FIG. 4 is a connection diagram of one example of this invention, FIG. 5 is a front view of the meter, and FIG. 6 is a connection diagram of another example of this invention. 1 is a meter.

Claims (1)

[Scope of utility model registration request] The input electrode of the transistor is supplied with the signal to be level-indicated, the output electrode of said transistor is connected to the hot side of a meter, the cold side of this meter is connected to one end of the power supply through a first resistor, this the other end of the power source is connected to the cold side of the meter through a series circuit of a normally open switch and a second resistor, and when the normally open switch is off, the level of the signal is displayed on the meter; A meter device in which the voltage of the power source is indicated to the meter when the normally open switch is turned on.