JPS6253132A - Charge display lamp circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application j) The present invention relates to a charging indicator circuit for indicating battery charging.

[Conventional technology l Commercial 2m! IG! Since f9mt sometimes supplies current to the load using an emergency battery, this battery must be constantly charged, and when charging, the charging indicator light is lit to indicate that charging is in progress. As shown in Figure 2, conventional nailing uses diode bridge rectification on the secondary side of the commercial power transformer! In the system d, which supplies and charges the rectified output of aD1 to the battery Ba through the charging adjustment resistor R1 and the diode D2, the charging? t
Connect a series circuit consisting of a charging indicator PL such as an LED and a resistor R2 in parallel to the f adjustment paper resistor R1, and turn off the charging indicator P during charging.
[was made to light up. Note that S is a load such as an inverter, and a switch.

[Problems to be Solved by the Invention] Does the conventional charging indicator device as described above require lighting that flows through the charging indicator light pt such as an LED? Ii current becomes 1 due to resistance R2
Even if you are using 111, if the battery is empty, the battery voltage is low, so please charge it! There is a problem in that the voltage across the r1 adjusting resistor R1 becomes high and an excessive ffi current flows through the charging indicator PL, causing damage to the charging indicator.

Therefore, the present invention provides a charging indicator circuit that prevents the above-mentioned aWi flow from flowing to the charging indicator even when the battery is empty.

Step 1 for solving 1 problem IjJ In order to solve the above problems, this Komei uses a charge indicator light and a resistor in parallel to the charge adjustment resistor in the charge indicator circuit. A bypass circuit consisting of a transistor having a constant voltage element connected to its base is connected in parallel to the charging indicator lamp.

[Effect]

When the battery is empty, the voltage across the charging adjustment resistor R1 is high, so the constant voltage element enables the transistor to turn on, and a bypass circuit is connected in parallel to the charging indicator.
As a result, excessive current is shunted to the bypass circuit and does not flow to the charging indicator PL.

[Example] Embodiments of the present invention will be described below with reference to FIG.

AC is a commercial RLI source, ■ is a power transformer for battery charging, 3a is an emergency battery, L is a load such as an inverter, and S is a switch.

Dl is a diode bridge rectifier T connected to the secondary side of the power transformer T, and its rectified output supplies a charging current to the battery 13a through a charging adjustment resistor 1 and a diode 1).

pH, 1 Resistor R2 and 6 with charging indicator light such as LED
and connect this series circuit to the charge adjustment resistor R1.
Connect in parallel.

7D is a constant voltage element such as a Zener diode, which is connected between the base resistor R3 of the transistor Q and the resistor R2 with the polarity opposite to the base. The collector of this transistor Q is connected between the resistor R2 and the charging indicator PL, and the emitter is connected to the other end of the charging indicator PL via the resistor R4, so that it can be bypassed in parallel with the charging indicator PT. The charging indicator circuit of the present invention, which forms the circuit, is constructed as described above. The rectified output of the rectifier D1 of the lf source is supplied to the battery Ba through the charging adjustment resistor R1 and the diode D2, and is charged.
The ffl current also flows and lights up to indicate that the battery is being charged.

Also, the bottle stand with an empty battery Ba is used for charging for the first time in poetry.
Since the battery voltage is low and a relatively large charging current flows through +, both resistors 11 of charge adjustment resistor 1 are 8, so resistor
Will you join 2? The tt pressure also increases, current flows through the constant voltage element ZD, and the transistor Q is turned on, thereby forming a bypass circuit in parallel with the charging indicator light PL. Therefore, even if a large charging current flows, it is shunted to the bypass circuit and an excessive current does not flow to the charging indicator light P[.
4. Furthermore, when the charging progresses sufficiently and the battery voltage rises, and there is no possibility that an excessive current will flow to the charging indicator pt, the transistor Q changes to A) and opens the bypass circuit.

In this way, whether the battery Ba is empty or not empty, the charging indicator PL can be lit to indicate when the battery is being charged.

[Effect of the invention J] As mentioned above, the charging indicator circuit of the present Komei has a charging indicator P
Series circuit of L and resistor R2 for charging adjustment 1! Connected in parallel to resistor R1, and based on constant voltage element 7D, 18
A bypass circuit consisting of a transistor Q is connected in parallel to the charging indicator light 1], so that when the battery Ba is empty, the transistor Q is turned on by the constant voltage element ZD, and the charging indicator light pt is turned on when the battery Ba is empty. The parallel bypass circuit is closed,
Therefore, an excessive current does not flow through the charging indicator PL, and damage to the charging indicator PL can be prevented.

Brief Description of the Drawings FIG. 1 is a circuit diagram of one embodiment of the present invention, and FIG. 2 is a circuit diagram of a conventional example.

Ba: Battery. La: Emergency light.

PE: Charging indicator. R1: Mitsuru? WtA for IfrAm.

Q: Transistor.

ZD: Constant voltage element.

Claims (1)

[Claims] A series circuit consisting of a charge adjustment resistor connected between the battery and a charging power supply, a charge indicator light and a resistor connected in parallel to the charge adjustment resistor, and a transistor connected to a constant voltage element as a base. A charging indicator lamp circuit comprising: a bypass circuit formed and connected in parallel to the charging indicator lamp.