JPH0233270Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an indicator circuit designed to reduce costs when switching and lighting a plurality of display means such as lamps and light emitting diodes.

When switching and lighting multiple display means such as lamps and light emitting diodes, transistors and the like are used for each display means to drive these display means, resulting in complicated circuit configurations and increased costs. I was getting used to it.

This invention was developed in consideration of the above points, and it is used in conjunction with a power supply circuit that switches in synchronization with the drive transistor of the display means, omitting the transistor, and supplying the drive current of the display means without going through the transistor. Therefore, it is an object of the present invention to provide an indicator circuit that can reduce the cost because the current of the transistor is small and a small heat sink is required.

Embodiments of the indicator circuit of this invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing one embodiment thereof. A and B in the figure indicate a first mechanism and a second mechanism, respectively, each having a predetermined function. These first mechanism A, second mechanism
Mechanism B is selected by turning the power on and off.

The power supply E is directly connected to the collectors of the transistors Q1 and Q3, and the indicators L1 and L
2 to the collectors of transistors Q4 and Q2 as a Swiss circuit. Indicators L1 and L2 are lamps, respectively.
The indicator L1 is for the first mechanism A, and the indicator L is a display means such as a light emitting diode.
2 is for the second mechanism B.

The emitter of transistor Q1 is connected to the first mechanism A, and a resistor R1 is connected between its collector and base. A diode D1 is connected between the base of transistor Q1 and the collector of transistor Q2.
is connected.

Similarly, the emitter of transistor Q3 is
It is connected to the second mechanism B, and a resistor R2 is connected between its base and collector. transistor Q
A diode D2 is connected between the base of the transistor Q4 and the collector of the transistor Q4. Furthermore, the emitters of transistors Q2 and Q4 are grounded.

Also, a resistor R3 is connected to the base of the transistor Q2.
A signal 1 from the changeover switch S is supplied through a resistor R4, and a signal 2 from the changeover switch S is supplied to the base of the transistor Q4 through a resistor R4.

Note that when the diodes D1 and D2 are used as the indicators L1 and L2, respectively, as light emitting diodes,
This is to prevent the light emitting diode from lighting up due to reverse current.

Next, the operation of the indicator circuit of this invention constructed as above will be explained.

First, the case of operating the first mechanism A will be described. In this case, the signal 2 of the changeover switch S is set to "H" level to turn on the transistor Q4. This turns off transistor Q3.

At this time, the signal 1 of the changeover switch S is set to "L" level, the transistor Q2 is turned off and the transistor Q1 is turned on, the voltage of the power supply E is applied to the first mechanism A through the transistor Q1, and the first mechanism A starts operating. conduct.

At the same time, current from power source E flows through indicator L1 and transistor Q4 to ground, causing indicator L1 to light up, indicating that first mechanism A is in operation.

In addition, when operating the second mechanism B, reverse the above and set the signal 1 of the changeover switch S to "H".
At the same time, signal 2 is set to "L" level. As a result, the transistor Q2 is turned on, the transistor Q1 is turned off, and the voltage of the power source E is no longer applied to the first mechanism A.

Similarly, the transistor Q4 is off, the transistor Q3 is on, and the voltage of the power source E is applied to the second mechanism B via the transistor Q3. As a result, the second mechanism B starts operating, current flows through the indicator L2 and the transistor Q2, the indicator L2 lights up, and the second mechanism B starts operating.
is running.

Thus, when the first mechanism A is in operation, the indicator L1 is switched on by the transistor Q4, and a drive transistor for the indicator L1 becomes unnecessary. Furthermore, during the selection operation of the second mechanism B, the indicator L2 is switched on by the transistor Q2, and a drive transistor for the indicator L2 becomes unnecessary.

In the above embodiment, the first mechanism A operates when the indicator L1 lights up, and the second mechanism operates when the indicator L2 lights up, but the transistors Q1 and Q3 are PNP type transistors, and their emits If the collectors of these are connected to the power supply E and each mechanism, when the signal 1 of the changeover switch S is set to the "H" level and the signal 2 is set to the "L" level, the transistor Q2 is turned on, the indicator L2 lights up, and the transistor Q1 becomes conductive, the first mechanism A operates, and one transistor Q3 and the indicator L1 are both turned off. If the signal of the changeover switch is reversed, the indicator L1 lights up in the same way and the second mechanism operates, so that the normally recognized operation of the display means coincides with the operation of each mechanism.

Further, in the above embodiment, the case where there are two each mechanism and each indicator is illustrated, but even if there are three or more each mechanism and each indicator, the transistor Q1, which is a component related to the mechanism A, for example,
Q2, resistors R1, R3, indicators L2, diodes D1, etc. are connected in accordance with the number of mechanisms, and furthermore, by making a predetermined one of the signals of the changeover switch different from the level of the other signals, the effect of the present invention can be obtained. Of course it can be played.

Fig. 2 is a circuit diagram showing another embodiment of this invention, showing the lighting of the indicators for the three mechanisms and the corresponding circuits of the mechanism parts, and turning "H" only on the mechanism part you want to operate from the changeover switch S. , and the others are set to "L", for example, the lighting of L2 and the operation of Q3 and mechanism part B match, and the current of indicator L2 is directly supplied from power supply E without passing through transistor Q3. It happens.

As described above, according to the indicator circuit of this invention, when switching and lighting multiple display means, the transistor for switching the power supply circuit is used in conjunction with the indicator circuit to switch the indicators. There is no need for a drive transistor provided for each indicator, making it possible to reduce costs. Also, since the current of the indicator does not flow through the transistor, you can use one with a small rating.
Moreover, the heat sink may also be small.

Specifically, as shown in FIG. 1, the display means L1 and L2 are placed on the power supply side, and the power supply E is supplied to each mechanism section A and B via (transistors Q1 and Q2). Compared to the case where a current is required to display the indicator at the stage after the power supply transistor, the current burden on the transistor is lighter, and it also has the effect of suppressing conventional heat loss. .

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of one embodiment of the indicator circuit of this invention, and FIG. 2 is a circuit diagram of another embodiment of the indicator circuit of this invention. A...First mechanism, B...Second mechanism, L1, L2
...Indicator, Q1-Q4...Transistor, E...Power supply, S...Selector switch, D1, D
2...Diode, R1-R4...Resistance.

Claims (1)

[Scope of utility model registration request] A plurality of mechanisms exhibiting respective functions, a plurality of display means corresponding to the plurality of mechanisms and displaying operating states of the plurality of mechanisms, and a power supply supplying an amount of electricity to the plurality of mechanisms and the display means. a plurality of transistors interposed between the power supply and the plurality of mechanisms; a plurality of control transistors each having an output connected to a control terminal of the plurality of transistors and controlling the transistors respectively; The indicator circuit includes a changeover switch that outputs a predetermined signal to turn on and off each of the plurality of control transistors. By operating the display means connected between the outputs of the transistors, operating the transistors by the output of the control transistor, and supplying the power to at least one of the mechanisms corresponding to the operated display means. , when the predetermined mechanism is selected by the changeover switch, the display means corresponding to the selected mechanism is energized from the power supply, and the supply of power from the power supply to the unselected mechanisms is stopped. An indicator circuit characterized by: