JPS58123333A - Charger - 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] The present invention is a counterfeit to the charging completion display circuit of a charger, and its purpose is to provide a charger that can reliably display the charging completion display even if the input voltage changes significantly. The present invention will be described below with reference to embodiment figures. FIG. 1 shows a block diagram of one embodiment.
FIG. 2 shows its specific circuit diagram. 11) in the figure is a rectifier circuit for rectifying AC power supply AC to obtain DC (pulsating current).
(2) is a transistor inverter for high frequency conversion of the direct current from the rectifier circuit (1), and this transistor inverter (2) is a power converter +
4), a switch section (5) consisting of a Japanese cedar transistor t, a switch starting circuit section (g), a switch starting M circuit section (6) consisting of a base feedback winding -Ll, and a secondary winding. It is composed of a secondary output rectifier circuit section (8) consisting of a wire 1, etc. In addition, primary winding Lh secondary winding 11iL
s, base feedback winding, and eighth winding L4 are wound around the same core to form an oscillation transformer T. - is an automatic voltage control circuit that controls the on-time of the switch section (!1) of the transistor inverter (2), and this automatic voltage control circuit - is O
Controlled by the output of the R circuit. (11) is connected to the secondary output rectifier circuit section ts+ of the transistor inverter (2) and is compared with the threshold 1 hold voltage Web corresponding to the predetermined charging completion voltage of the secondary battery 1B such as a 9Ml-Cd battery. This is a charging completion voltage detection circuit for detecting the completion of charging of the secondary battery i11, and its output is input to the OR circuit (to). In order to provide hysteresis operation, there is no difference between the threshold voltage Vthi when rising and the threshold voltage Vthb when falling. θ field is a power supply circuit that supplies power to the above-mentioned charge completion voltage detection circuit, and is composed of a step-down resistor R8 and a smoothing capacitor C1, and is connected to this circuit and the charge completion detection circuit (1).
1) constitutes an overcharge control circuit. (9) is a rectifier circuit composed of a tertiary winding 6, etc., and supplies power to the automatic voltage control circuit. Next, the configuration of the automatic voltage control circuit consisting of KIC04 will be described. (Foundation) is a rectifier circuit (
9) An automatic voltage control circuit receives the output from the automatic voltage control circuit - a stabilized power supply circuit for supplying power to each part. The reference voltage circuit generates a reference voltage, and the sensor circuit generates a current 1 flowing through the primary winding.
11) is ejected and compared in a comparison circuit. Kan is an oscillation circuit that receives the output of an external circuit Q@ consisting of a capacitor Ca and a resistor R^, and generates a sawtooth wave of a reference frequency. This output is converted into a pulse wave by the T-flip-flop (c) and input to the main circuit of the company. The output of the automatic voltage control circuit is input to the above OR circuit (1 (1)) and is logically operated with the output of the charge completion voltage detection circuit (U). This is a low voltage protection circuit to prevent malfunction of the circuit. Also, ■-■ indicates each terminal of ICα.Also, it is a charging completion display circuit which is the main component of the present invention, and resistor R2, charging completion It consists of a light emitting diode D, which is a light emitting element for display, and is supplied with power from the output of a reference voltage circuit of an automatic voltage control circuit.

Next, the operation of the circuit of the present invention will be explained.

Now, when the AC power source AC is connected, the transistor inverter (z)
is the switching transistor Tr of the switch part (6)
A base current flows through the base of the switch activation accelerator circuit section (7) and the base feedback winding 411Ls to start the oscillation operation.

In this case, the 112 rechargeable battery (3) is uncharged, and the voltage across it is ■. is smaller than the threshold voltage vth of the charge completion voltage detection circuit (3g), the output of the charge completion voltage detection circuit (11) to the OR circuit α4 becomes 1H# level Kl
a will be held. Then, during the period when the output from the automatic voltage control circuit to the OR circuit (to) is at the 1H# level, the output from the OR circuit (field) is set to the 1H# level, and as a result, the transistor inverter (2) is turned on, and the OR circuit (to) is at the 1H# level. The output of the seagull is 1H"
Lasts for the duration of the level.

During the ON period of this transistor inverter (2), primary current flows through the primary winding 111L+! 1p is the input voltage vXN
flows in proportion to. The value of the primary current 11p is detected by the sensor circuit section, and its liquid output output V is inputted to the comparison circuit. ``On the other hand, from the output of reference voltage circuit 4 to the comparison circuit -
The company reference voltage Vref is input. And Vra
When f<Vm, the output of the comparator circuit reaches the 1H# level. As a result, the automatic voltage control circuit (A) to the OR circuit (
The output to the oscillation transformer T becomes 1L level, and the switching transistor Tr of the transistor inverter (2) is abruptly turned off to stop the oscillation operation. By stopping the oscillation operation, the magnetic energy stored in the oscillation transformer T is is 2
It is discharged through the secondary winding @L3 of the next output rectifier circuit section (S), the rectifier diode D2, and the closed circuit of the secondary battery (3), and the secondary battery (3) is charged. As a result, the primary current 11p of the transistor inverter (2) is kept constant even if the input voltage Win changes, and as a result, the charging current becomes constant. In this case, the input voltage is stabilized at AClooV -270V. The reference voltage Vref is determined as follows, and the transistor inverter ('1) is controlled by the automatic voltage control circuit. Once you set up /, you will be able to use it not only in Japan but also in other countries without using an adapter.

The secondary battery (3) is charged in this way, and when the voltage v0 across it rises and exceeds the threshold voltage Vtb@ shown in FIG. 8(a) in the charging completion display circuit, the OR
The charge completion detection circuit (1K) sets the output to the circuit - to the voice L level, and the output of the OR circuit - is fixed to the %L level regardless of the output of the automatic voltage control circuit -, and as a result, the switch: /I) Transistor inverter (21Fi
Stops oscillation and stops charging the secondary battery (3). This 2
The voltage V・ across the next battery il+ decreases due to natural discharge, etc., and the threshold voltage vthb shown in FIG.
At a lower level, the inverter (2) operates in oscillation in the same manner as described above, and charges the secondary battery (3). Thereafter, this operation is repeated to suppress the charging current. 4s3-Figure (i) (b) is the charging current
It shows a time chart to explain the operation of suppressing the upper threshold voltage Vth and the lower threshold voltage Vthb
While the voltage of the secondary battery ('X) is rising between During the period until it drops due to natural discharge etc. and reaches the lower threshold voltage VthbK, the charging current is quickly cut off (3), where the voltage vo at both ends becomes the threshold voltage V
Since the value is close to thmevthb, the on time tON of the switching transistor Tr of the transistor inverter (2) is about 1/2-115 of the normal initial current,
The charging current decreases accordingly, and overcharging is prevented.

Here, when the oscillation of the transistor inverter (2) stops, current generation from the 8th winding L4 of the rectifier circuit (9) is eliminated, and the power supply voltage of the automatic voltage control circuit is reduced to a certain constant value. When this occurs, the voltage across the charging completion display circuit (light-emitting diode D) becomes 1L# level to turn off the light, and when the oscillation circuit of the transistor inverter (2) is operating, the voltage across the light-emitting diode D In order to keep the voltage almost constant, the charging completion voltage detection circuit (l
- is getting power, for example, input voltage v of AC power supply AC
When IN changes from 100V to -270V, the output voltage from the 8th winding changes almost proportionally, but the output voltage of the reference voltage circuit always remains constant during the oscillation of the transistor inverter (2). As a result, the brightness of the light-emitting diode D remains constant even if the power supply voltage changes as described above. When the threshold voltage Vth of the charge completion detection circuit (11) is lower than b, the IK will turn on the charge completion display circuit (the light-emitting diode Di connected to I will light up.Then, the charging progresses and the voltage across both terminals V will decrease to V).
・> vth b K & Then, the overcharge control circuit operates, and as shown in FIG.
The voltage generated at the tertiary '141 L4 of ill also decreases in proportion to this, so that the current supplied to the charging completion display circuit becomes small, causing the light emitting diode D to turn off or blink. One aspect of the present invention is a transistor inverter that charges a secondary battery with an oscillation output, a charging completion voltage injection circuit that generates a first stage detection signal when the voltage across the secondary battery reaches a predetermined level or higher, and a transistor inverter. Equipped with an automatic voltage control circuit that generates a signal when the voltage of the supplied power source exceeds a predetermined level, and stops the oscillation operation of the transistor inverter when a detection signal from the charging completion voltage detection circuit or an output signal from the automatic voltage control circuit is generated. Since the charger is designed to control the oscillation period of the transistor inverter in response to the input voltage, it is possible to obtain a stable charging current regardless of the input voltage. This device can be used in the true region without an adapter, and it stabilizes the oscillation output of the transistor inverter and supplies it to the automatic voltage control circuit, and the stabilized power source lights up a light emitting element to indicate charging completion. Since it is equipped with a charging completion display circuit that allows the input voltage to vary, the brightness of the lighting of the light emitting element for displaying charging completion during the oscillation operation of the inverter remains constant.
Even in areas where the input voltage is low or high, the lighting display will remain steady, and the output voltage of the stabilized power supply can be lowered while the transistor inverter oscillates due to the operation of the charging completion voltage detection circuit. As a result, it is possible to reliably turn off the light-emitting element for indicating completion of charging to indicate completion of charging.

[Brief explanation of the drawing]

Figure 1 is a block diagram of an embodiment of the present invention, Figure 2 is a specific circuit diagram of the same as the above, Figure 3-) (b) is a time chart for explaining the operation of the same, and (2) is a transistor inverter. , (3) is a secondary battery, (kl)H charging completion voltage detection circuit, OIF! The charging completion indicating circuit, D, is a light emitting diode. Agent Patent Attorney Ishi 1) Choshichi

Claims (1)

[Claims] (1) A transistor inverter that charges the secondary battery with oscillation output, a charging completion voltage detection circuit that generates a detection signal when the voltage across the secondary battery differs by more than a predetermined level, and a charging completion voltage detection circuit that supplies the voltage to the transistor inverter. Equipped with an automatic voltage/control circuit that generates a signal when the voltage of the power supply reaches a predetermined level or higher, and stops the oscillation operation of the transistor inverter when a detection signal from the charging completion voltage detection circuit or an output signal from the automatic voltage control circuit is generated. The charger is equipped with a charge completion display circuit that stabilizes the oscillation output of the transistor inverter and supplies it to an automatic voltage control circuit VcP, and lights up a charge completion display element using the stabilized power source. A charger featuring: