JPS6052776A - Voltage monitor circuit - Google Patents

Abstract

PURPOSE:To obtain a voltage monitor circuit which can respond to a change of the number of cells, by providing a sensor which senses the number of cells and setting a reference voltage or a detecting voltage in accordance with the change of the number of cells. CONSTITUTION:A resistance R2 constitutes a variable resistance which receives a signal of the number of cells from a sensor part B to change the resistance value. This sensor part B consists of light emitting elements 5, photodetectors 6, and a signal processing part 7 and detects the length of storage batteries BT. Light emitting elements 5 are connected in series, and photodetectors 6 are connected in series in accordance with individual elements 5. The required number of storage batteries BT are arranged in series between light emitting elements 5 and photodetectors 6. The light from light emitting elements 5 in positions where storage batteries BT exist is intercepted, but the light from light emitting elements 5 in positions where storage batteries BT do not exist reaches photodetectors 6. The photodetectors 6 and storage batteries arranged in series are allowed to correspond to each other to detect the length of storage batteries BT. Since the resistance value of the resistance R2 is larger when larger the number of cells and is smaller when smaller the number of cells, the detecting voltage is changed automatically in accordance with the number of cells.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a voltage monitoring circuit for a storage battery built into a guide light/emergency lighting equipment.

[Background technology]

Guidance lights and emergency lighting equipment are usually powered by commercial power,
In the event of a power outage, it automatically switches to the built-in storage battery and lights up in an emergency using inverter oscillation.

The voltage monitor circuit detects and displays the battery life by detecting that the battery voltage is lower than the specified value. That is, the voltage monitor circuit determines that the battery is at the end of its lifespan and issues a warning if the battery voltage decreases more than the specified value due to the emergency lighting of the appliance for a specified period of time. However, if the emergency lighting is then returned to normal lighting, the battery voltage will be restored by charging even if the battery has reached the end of its life.

For this reason, the voltage monitor circuit is provided with a memory function so that once the battery voltage falls below a specified value, it remembers that the battery life has expired.

FIG. 1 shows a block diagram of the voltage monitor circuit.

The circuit is mainly composed of a Schmitt circuit 4 and is driven by battery voltage. The constant voltage output from constant voltage circuit 1 and the battery voltage are connected to resistors R1 and R as Schmitt circuit 4.
The two voltages divided by 2 are input. When the battery voltage is normal, resistors Ri, R2,
If the constant voltage output value is set, the drive circuit 6 will not operate and the monitor light emitting diode LED will not light up. Now, when the battery voltage decreases and the divided voltage of resistors R1 and R2 drops below the constant voltage output voltage and below the lower trigger voltage of the Schmitt circuit, the circuit reverses and the light emitting diode LED
lights up.

If the upper trigger voltage of the Schmitt circuit is set sufficiently higher than the battery voltage, the light emitting diode LE will light up once.
Since D continues to light up even after the battery voltage is restored, it has a memory function.

Further, in order to turn off the lit light emitting diode LED, a reset circuit that applies a voltage pulse higher than the upper trigger voltage to the Schmitt circuit 4 is required, but this is omitted here for convenience.

Now, in this voltage monitor circuit, when the number of batteries (hereinafter referred to as the number of cells) changes, it is necessary to change one circuit constant and reset the operating point. Particularly when considering the use of ICs for voltage monitor circuits, preparing ICs according to the number of cells poses problems in terms of cost and development planning. In addition, mounting part of the circuit externally to the basic IC may cause mounting problems, and in equipment that requires a wide range of temperature characteristics, such as emergency lights, it is necessary to attach a part of the circuit externally to the basic IC. There is also a problem.

The present invention has been made in view of this point, and an object of the present invention is to create a voltage monitor circuit that can respond to changes in the number of cells.

[Purpose of the invention]

An object of the present invention is to provide a voltage monitor circuit that can respond to changes in the number of cells.

[Disclosure of the invention]

The gist of this invention is the reference voltage and battery! By comparing the pressure with a comparator, it'll! A sensor that detects the number of cells is installed in a voltage monitor circuit that detects and stores voltage abnormalities, and displays and warns about them.The reference voltage or detection voltage is set in response to changes in the number of cells. This is a voltage monitor circuit characterized by the following.

(Example 1) FIG. 2 shows Example 1 of the present invention. As shown in FIG. 2, the circuit consists of a conventional voltage monitor circuit part (1) and a sensor part (2) for detecting the number of cells. The part enclosed in parentheses in the figure is the sensor part (■) added to the voltage monitor circuit part (■). The voltage monitor circuit section (2) is almost the same as the conventional example, except that the input resistance R2 of the Schmitt circuit 4 is variable.

That is, the resistor R2 is a variable resistor whose resistance value changes in response to a signal indicating the number of cells from the sensor section. The sensor part (■) consists of a light emitting element 5 such as a light emitting diode, a light receiving element 6, and a signal processing part 7, and includes a storage battery BT.
Detect the length of. Each light emitting element 5 is connected in series, and a light receiving element 6 is connected in series corresponding to each light emitting element 5.

A required number of storage batteries BT are arranged in series between the light emitting element 5 and the light receiving element 6 arranged in series. Therefore, as the number of connected storage batteries BT is reduced, light from the light emitting element 5 enters the corresponding light receiving element B, and the signal processing section 7 is activated by the current flowing through the light receiving element 6 to change the resistance value of the variable resistor R2. This corresponds to the number of cells detected. That is, when the storage battery BT is present, the light from the light emitting element 5 is blocked, and in the area where the storage battery BT is not present, the light from the light emitting element 5 is blocked by the light receiving element 6.
reach up to. The light receiving elements 6 and the storage battery B arranged in series
Since T is associated, the length of the storage battery BT can be detected. The resistance R2 has a large resistance when the number of cells is large, and a small resistance when the number of cells is small, so that the detection voltage automatically changes depending on the number of cells.

Of course, a similar effect can be obtained with a structure in which the resistance R1 changes, and the reference constant voltage may also be changed. In this way, the present invention can automatically change the detection voltage even if the number of cells is changed. Furthermore, the amount of light leaking from the light emitting element 5 to the light receiving element 6 can be detected and used to check if the battery has been forgotten to be connected.

(Example 2) Example 2 of the present invention is shown in Figure M6. The configuration shown in FIG. 6 also consists of a conventional voltage monitor circuit section (2) and a sensor section for detecting the number of cells.

Portion (2) of the voltage monitor multi-circuit is the same as in the first embodiment, so its explanation will be omitted here.

The sensor part [phase] consists of a pressure sensor 8 arranged corresponding to each cell and a signal processing part 9,
The presence or absence of storage battery BT is detected by pressure and the number of cells is known. The resistance value of variable resistor R2 is increased when there are many cells,
The detection voltage is increased, and when the number of cells is small, the resistance value is decreased and the detection voltage is lowered, so the detection voltage can be automatically changed according to the change in the number of cells.

Note that, as in the case of the above example, a resistor R is used instead of the resistor R2.
A similar effect can be obtained even if the constant voltage output voltage is changed by changing 1.

〔Effect of the invention〕

As described in detail above, the present invention has the advantage that the detected voltage can be automatically changed by adding a sensor without making any changes to the conventional voltage monitor circuit.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional example, FIG. 2 is a block diagram showing a first embodiment, and FIG. 6 is a block diagram showing a second embodiment.

Claims (1)

[Claims] (1) Abnormalities in battery voltage are detected and stored by comparing the reference voltage and battery voltage with a comparator. In the voltage monitor circuit structured to display and warn about this,
A voltage monitor circuit characterized in that a sensor for sensing the number of cells is installed and a reference voltage or detection voltage is set in response to a change in the number of cells.