KR910000528Y1 - Automatic transfer circuit of piloting range for power meter - Google Patents

Abstract

No content.

Description

Power meter display range automatic conversion circuit

The accompanying drawings are detailed circuit diagrams illustrating embodiments of the present invention.

* Explanation of symbols for main parts of the drawings

10: level comparison unit 20: input signal selection unit

30: meter drive unit 40: display range indicating unit

50: level setting holding unit 60: level setting signal generating unit

SW1, SW2: Analog Switching Integrated Circuit

IC1: Meter Drive Integrated Circuit IC2: Comparator

IC3: flip-flop

The present invention relates to a circuit for automatically converting the display range of the power meter.

Conventional analog meter driving circuit has a disadvantage that the display range is narrow and the switch must be operated by installing an attenuation circuit in the meter input circuit in order to enlarge the display range. When applied, the circuit is unreasonable, and there is a problem in that it is difficult to grasp the display range by displaying the switch position, the light emitting diode, or the like in the display range.

The present invention has been made to solve the above-mentioned problems. When the display range of the meter is expanded, a switching integrated circuit is used instead of a switch, and the meter is integrated by detecting a level with a comparator composed of an operational amplifier and driving a flip-flop. In addition, the input level of the circuit is automatically converted, and the improved power meter display range automatic conversion circuit is provided to facilitate the identification of the display range by automatically converting the color of the illumination lamp of the meter. Its purpose is to.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The present invention rectifies the output signal of the amplifier to compare the comparison voltage with the level comparison unit 10, and the level for applying the control signal to the level setting holding unit 50 in accordance with the output signal of the level comparison unit 10 A level setting holding unit 50 for generating a control signal of the input signal selecting unit 20 in accordance with a setting signal output unit 60, an output signal of the level setting signal generating unit 60, and the level setting holding unit An input signal selector 20 for selecting and outputting an input signal according to the output signal of 50, an meter driver 30 for driving the meter by the output signal of the input signal selector 20, and the level setting It is comprised as the display range indicating part 40 which shows a display range by the output signal of the holding part 50. As shown in FIG.

Referring to the operation of the circuit of the present invention having the above configuration is as follows.

In the level comparison unit 10, when the output of the amplifier is input, it is rectified by the diode D1 and input to the comparator IC2. At this time, the resistor R2 and the capacitor C1 are for maintaining the operation time.

On the other hand, the reference voltage is set in the comparator IC2 by the resistor R11 and the zener diode ZD1 so that the high level output signal appears only when the signal input through the diode D1 is larger than the reference voltage.

In the level setting signal generator 60, when the high level signal is output from the comparator IC2, the transistors Q1 and Q2 are turned on and the pulses rectified by the diodes D2 and D3 through the pulse generating capacitor C4 are generated. Is output.

In the level setting holding section 50, the output pulse of the diode 2 is applied to the set terminal S of the flip-flop IC3 to output a high level signal from the output terminal Q, thereby selecting an input signal. In the unit 20, the analog switching integrated circuit SW1 is turned on so that the input signal is input to the m driving integrated circuit IC1 of the m driving unit 30 through the 0 dB level setting resistor R4 to drive the display meter M1. Done. Not described Capacitors C2 and C3 are for bypass, and resistor R10 is a variable resistor for meter level adjustment.

On the other hand, in the display range indicating section 40, the high level signal is output from the output terminal Q of the flip-flop IC3, and the lamp driving transistor Q4 is turned on. Lamp LAMP1 is operated because it flows through transistor Q4, and at the same time, it flows to transistor Q4 through resistor R17 and light emitting diode LED2, so that light emitting diode LED2 also emits light, thereby operating 0dB. It indicates that it is.

Contrary to the above state, when the signal applied to the comparator IC2 by the output signal of the amplifier input to the level communication unit 10 is smaller than the reference voltage set by the resistor R11 and the zener diode ZD1, the comparator ( The low level signal is output from the IC2, and the transistors Q1 and Q2 of the level setting signal generator 60 are turned off, so that the pulse generated at the OR gate OR1 is reset terminal R of the flip-flop IC3. ) Is applied to output the high level signal from the inverting output terminal Q. This causes the analog switching integrated circuit SW2 of the input signal selector 20 to be turned on so that the input signal has a -20 dB level setting resistance (R5-R7). ) Is input to the meter driving integrated circuit IC1 of the meter driving unit 30 to drive the display meter 1.

In addition, since the transistor Q3 is turned on by the high level signal outputted from the inverted output terminal Q of the flip-flop IC3, the power supply B ″ is turned on through the lamp LAMP2 and the diode D6. It is applied to the collector and at the same time is applied to the collector of the transistor Q3 through the resistor (R16) and the light emitting diode (LED1) to indicate that the lamp (LAMP2) and the light emitting diode (LED1) to operate -20dB.

On the other hand, when the mode high level is applied to the set terminal S and the reset terminal R of the flip-flop IC3, it does not occur due to the circuit configuration. In the initial state, the capacitor C5 of the level setting signal generator 60 is generated. And a diode (D4, D5), the pulse is applied to the reset terminal (R) through the OR gate (OR1) to output a high level signal to the inverting output terminal (Q) of the flip-flop (IC3) analog switching integrated circuit It will turn on (SW2).

In addition, (LAMP1, LAMP2) of the display range indicating unit 40 is composed of red and blue light, respectively, so that the user can easily recognize the current display range.

As described above, according to the present invention, the protection of the meter against over-input can be performed by automatically expanding the indication range of the analog meter according to the input signal, and the indication range of the meter is represented by a color lamp. There is an advantage that can be easily recognized.

Claims (1)

The control signal of the level setting holding section 50 according to the output of the level comparing section 10 and the level comparing section 10 which detects the output signal of the amplifier and compares the reference voltage with the comparator IC ₂ is output as a pulse. The level setting holding unit 60 generates the output of the flip-flop IC ₃ according to the output of the level setting signal generating unit 60 and the level setting signal generating unit 60 to be generated and applied to the input signal selecting unit 20. 50) and the input signal selection for selectively outputting the amplifier output signal through 0dB and -20dB level setting resistors by switching the analog switching integrated circuits SW ₁ and SW ₂ by the output signal of the level setting holding section 50; The meter driver 30 driving the display meter M ₁ through the meter driver integrated circuit IC ₁ by the output signal of the input signal selector 20 and the level setting holding part ( by by the output signal 50) drives the transistor (Q _3, Q ₄₎ lamps (lAMP _1, lAMP ₂₎ and the light emitting diode (LED _1, LED ₂₎ that comprises a display range designating section 40, showing an operating condition characterized by a power meter display range automatically converting circuit for a.