JPS635401Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is provided with a charging section 2 that charges the battery 1 and a timer section 3 that turns off the charging section 2 after a set time, and when charging the battery 1 with a load 4 connected to it. A set time switching circuit 5 that shortens the set time of the timer section 3 and a charging current switching circuit 6 that increases the charging current are provided, and a reset circuit 7 that resets the timer section 3 at the time of startup and a set time elapsed time of the timer section 3 are provided. This relates to a charging circuit which is provided with a load off circuit 8 that later turns off the load 6, and is provided with an indicator light 9 that lights up during charging of the battery 1.

The purpose of this invention is to automatically turn off the charging part after charging is completed to prevent the battery from overcharging, and also to prevent damage to the charging circuit. In addition to being able to obtain sufficient current to energize the battery, it can be charged in a short time, and after charging is completed, charging and power to the load are automatically cut off to ensure safety, and furthermore, it is possible to notify the user that charging is complete. The purpose is to provide a charging circuit.

Conventionally, some charging circuits for batteries used in electric shavers and the like that require long charging times, such as 8 hours or 15 hours, display a power-on lamp, but some do not display this even when charging is complete. The disadvantage is that the user is unsure whether charging is complete or not, and if the load is connected and the charging circuit is left unattended, the charging circuit will be damaged due to heat generated by the circuit components. It had

The present invention has been made in view of the above points, and will be described in detail below with reference to the following examples.

In FIG. 1, a battery 1 is charged by a charging section 2, and the charging section 2 is turned off after a set time of a timer section 3 has elapsed to stop charging. First, the operation of charging section 2 will be explained.

When the AC input is full-wave rectified by the rectifier 10, and a starting current flows from the power source to the base of the output transistor _T3 via the starting resistor _R5 and the base winding _L3 ,
The output transistor T ₃ is rapidly turned on due to the positive feedback action of the collector winding L ₁ and the base winding L ₃ . When the collector current of the output transistor T ₃ increases to a certain value, the emitter resistance R ₇ (when charging the switch
The voltage across SW ₄ (SW 4 is off) rises, turning on control transistor T ₂ . Therefore, the control transistor T ₂ bypasses the base current of the output transistor T ₃ and the output transistor T ₃ is turned off.
At this moment, a charging current flows as shown in FIG. 2b.
At this time, capacitor C ₄ is connected to output transistor T ₃
is charged so that the output transistor is turned off.
The base-emitter voltage V _BE of T ₃ takes a negative value as shown in Figure 2c. The charge on capacitor C ₄ is transferred to resistor R ₆
When the output transistor T ₃ is forward biased by discharging through and charging through the resistor R ₅ and V _BE takes a positive value, FIG.
The collector current begins to flow again as shown in FIG. Note that FIG. 2a shows the collector-emitter voltage of the output transistor _T3 . Then, by varying the emitter resistor R ₇ , the collector current of the output transistor T ₃ can be varied, and by increasing the resistor R ₇ , the collector current of the output transistor T ₃ becomes smaller.
The charging current can be made smaller, and conversely, if the resistor R ₇ is made smaller, the collector current of the output transistor T ₃ becomes larger, and the charging current becomes larger. Taking advantage of this point, the charging current switching circuit 6 composed of the switch SW ₄ and the resistor R ₈ is connected in parallel to the resistor R ₇ . Switch SW ₄ is a switch for driving load (motor) 4.
In conjunction with SW ₅ , when charging battery 1, switch SW ₄ ,
Switch SW ₅ is off, and a charging current is passed that will not cause overcharging even when charging for a long time. When battery 1 runs out of capacity, switch SW ₄ is turned off from the AC power supply
By turning on SW ₅ , the emitter resistance of the output transistor T ₃ is reduced, the charging current is increased, and the load 4 is energized. This made so-called AC drive possible. While the output transistor _T3 is on, the voltage across the collector winding _L1 is induced in the output winding _L2 , and that voltage causes current to flow through the resistor _R9 to the indicator light (light emitting diode) 9, indicating energization. do. In order to stop this oscillation, it is sufficient to keep the transistor _T1 of the timer section 3 on at all times to bypass the base current of the output transistor _T3 , and at that time the indicator light 9 also goes out.

Next, the timer section 3 will be explained. resistance
A constant voltage block is formed by R ₁ , Zener diode D ₁ , and capacitor C ₁ , and the timer circuit 11
When power is supplied to V _S of , the SET signal is input, and the timer circuit 11 starts counting. The counting period is determined by the resistor Rt, the capacitor _C3 , and the time constant of the set time switching circuit 5. Then, after a certain count, _Vput goes to "H" level, turning on transistor _T1 . Switch SW ₁ ,
SW ₂ , SW ₄ , and SW ₅ all work together, and switch SW ₁
When is on, the other switches _SW2 to _SW5 are off, and switch _SW2 is a reset type switch. L ₄
is a relay having a normally closed contact SW ₆ , which forms a load-off circuit 8.

If you only want to charge battery 1 now, turn on switch _SW1 and turn off switches _SW2 to _SW5 . When AC input is applied at time _t0 in FIGS. 3a to 3d, the timer circuit 11 starts counting as described above. At this time, since the switch SW ₃ is off, the counting period is determined by the time constant determined by the capacitor C ₃ and the resistor R _S. In this state
V _put is "L", and at time t ₁ after a certain count (set time), V _put becomes "H", turning on transistor T ₁ and turning off normally closed contact SW ₆ by relay L ₄ . However, in this case, even if the normally closed contact SW ₆ is turned off, it has no effect on charging. Transistor T ₁
By turning on, the base current of output transistor _T3 is bypassed and oscillation stops. Therefore, the indicator light 9 goes out, informing the user that charging has ended. Then, at time _t2 , the AC input is turned off.
Note that in this case, since the switch _SW4 is off, the charging current is small.

Next, when performing AC drive after the start of charging and before the end of charging, first, the time t ₀ of FIG. 4 a to d is
Start charging by applying AC input at time t1, turn off switch _SW1 at time _t1 , turn on switch _SW2 (but return to off), and switch _SW3 to _SW5 as follows.
and normally closed contact SW ₆ is turned on. switch
By turning SW ₁ off and switch SW ₂ on,
A reset circuit 7 having a differentiating circuit including a capacitor C ₂ and a resistor R ₁₀ operates to reset the timer circuit 11 and start counting from the beginning. At this time, since switch SW ₃ is also on, the setting time switching circuit 5 is connected, and the combined resistance of resistors Rt and R ₄ becomes smaller than Rt, the time constant becomes smaller, and the setting time of the timer circuit 11 becomes shorter. It becomes like this. Also, switch
Since SW ₄ is on, the charging current switching circuit 6 is connected and the charging current increases. Timer circuit 11
V _put of the timer circuit 11 at time t ₂ after the set time of
becomes “H”, turns on transistor _T1 , stops charging, and further prevents battery 1 from being over-discharged.
A normally closed contact SW ₆ is turned off by means of a relay L ₄ forming a load-off circuit 8 that turns off the load 4 . time t ₃
Turn on switch SW ₁ and turn on switch SW ₂ to _{SW 5} .
When you turn it off and start charging again, the time constant
Returning to _C3 Rt, the RESET signal is input again and the timer circuit 11 is reset, and then the charging time is counted. At time _t4 , the transistor _T1 is turned on, and the charging is completed.

Fig. 5 shows an embodiment in which the indicator light 9 blinks after the battery is fully charged.The AC input is step-down rectified through a transformer T and a diode D, and a timer circuit 11 is operated by a resistor _R1 , a capacitor _C1 , and a Zener diode _D1 . Generates the constant voltage necessary to drive '. SW is a limit switch that is automatically turned on when the battery 1 is inserted into the adapter 12 as shown in FIG. This limit switch SW
When turned on, the timer circuit 11 starts operating.
The timer circuit 11' is set to one hour, for example, and the transistor is turned off during charging, that is, within one hour.
Since T ₄ is off, the indicator light (light emitting diode)
9 is lit. When the set time of the timer circuit 11' has elapsed, an output is output from the timer circuit 11' and inputted to the CR oscillation circuit 13, which generates a pulse to turn on and off the transistor _T4 and turn on the indicator light. Flash 9. Therefore, the completion of charging can be clearly notified.

As mentioned above, the present invention is provided with a charging section that charges the battery and a timer section that turns off the charging section after a set time, so that the charging section can be automatically turned off after charging is completed to prevent overcharging of the battery. Further, a setting time switching circuit for shortening the setting time of the timer section and a charging current switching circuit for increasing the charging current when charging the battery by connecting a load to the battery is provided, and the timer section is reset at the time of starting. We have provided a reset circuit and an off circuit that turns off the load after the time set in the timer section has elapsed, so when charging with the load connected, sufficient current can be obtained to pass through the load, and charging can be done in a short period of time. It is possible to cut off charging and power to the load after the battery has been charged, thereby ensuring safety by preventing damage to circuit components due to forgetting to turn off the battery.Furthermore, an indicator light that lights up while the battery is being charged is provided so that the user can easily indicate when charging has finished. This has the effect that the information can be reliably notified.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of an embodiment of the present invention, Figure 2a
~d is the main part voltage and current waveform diagram of the charging part same as above, 3rd
Figures a to d are time charts when only charging the same as above, Figures 4 a to d are time charts when charging with the load connected to the above, and Figure 5 is a time chart of another embodiment of the present invention. The circuit diagram and FIG. 6 are longitudinal sectional views of the same essential parts. DESCRIPTION OF SYMBOLS 1... Battery, 2... Charging part, 3... Timer part, 4... Load, 5... Setting time switching circuit, 6...
...Charging current switching circuit, 7...Reset circuit, 8...
...Load off circuit, 9...Indicator light.

Claims (1)

[Scope of utility model registration request] A charging section that charges the battery and a timer section that turns off the charging section after a set time are provided, and when a load is connected to the battery and the battery is charged, a set time switching circuit that shortens the set time of the timer section and a setting time switching circuit that increases the charging current. A charging current switching circuit for switching the battery is provided, a reset circuit for resetting the timer section at startup, and a load off circuit for turning off the load after a set time of the timer section has elapsed, and an indicator light is provided for the battery that lights up while the battery is being charged. A charging circuit consisting of