JPH0550948U - Charger - Google Patents

Abstract

(57) [Summary] [Purpose] Since the conventional Ni-cd battery cannot determine the residual capacity from the outside, the Ni-cd battery which has not been discharged may be rapidly charged again. Therefore, it is an object of the present invention to prevent a problematic decrease in battery life. [Structure] In order to solve this problem, the present invention determines the battery voltage by applying a constant load current to the Ni-cd battery before charging, and selects quick charge, normal charge, or trickle charge corresponding to the judgment voltage value. It is designed to be charged.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a Ni-cd charger.

[0002]

[Prior Art]

 FIG. 2 is a block diagram of a conventional charger. This operation will be described below. When the Ni-cd battery BT is inserted in the charger and the current switch S is connected, the AC100V input passes through the power transformer T and becomes a direct current by the rectifying diode 1. The switching transistor of 2 becomes conductive when the timer of 3 does not operate, and the Ni-cd battery is charged with a current value determined by the resistance values of R1 and R2. When the timer 3 is activated and the switching transistor 2 is controlled to be non-conductive after a lapse of a certain time after the power is turned on, the Ni-cd battery BT is charged with a current value determined by the resistance value R1.

The resistance values R1 and R2 are set to R1 >> R2, R1 is set to a constant trickle charging current value, and the parallel resistance value of R1 and R2 is set to a constant charging current value. As for the charge display, D3 is lit during the rapid charge and D4 is lit during the trickle charge.

[0004]

[Problems to be solved by the device]

 The battery which has not been discharged by the above-mentioned conventional charging may be rapidly charged again. The present invention solves this drawback by supplying a constant current to the Ni-cd battery at the start of charging and measuring the battery voltage to obtain the measured voltage value. Correspondingly, the charging current value is determined.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention connects a load resistance to a Ni-cd battery at the start of charging and applies a constant current, and the battery voltage at this time is judged by a comparator and the rapid charging and normal charging are performed according to the measured voltage value. , It is designed to select a charging flow that supports trickle charging.

[0006]

[Action]

 To explain the operation of the present invention, the charging method is selectively controlled so that when the measured voltage is low, fast charging, when it is high, trickle charging, and when it is intermediate, normal charging is performed.

[0007]

【Example】

 FIG. 1 is a block diagram of the present invention. This operation will be described below. When the power switch S is connected, 100 V AC is input to the T power transformer, and when the DC voltage is output from the rectifier 1, the timer circuit 4 operates for a certain period of time to operate 16 relays. When the relay 16 operates, the Ni-cd battery is connected to the load resistor R11 and the voltage value at this time is judged by the comparators 13, 14, and 15.

When the voltage value is low, only the output of the comparator 13 operates, and when the voltage value is high, the outputs of the comparators 13, 14, 15 all operate. In the case of the intermediate value, the comparators 14 and 15 operate. The output of the comparator is stored in the RS flip-flops (FF) of 10, 11, and 12, and when only the comparator 13 operates, R-S and FF10 are memory, and when the comparators 14 and 15 operate, R -When S, FF11 is a memory and all comparators 13, 14, 15 are operated, R, S, FF12 are memorized.

When the RS and FF 10 operate, the switch transistor circuit 5 becomes conductive. When RS and FF11 operate, the switching transistor 6 becomes conductive. R5, R6 and R7 are resistors for setting the charging current, and R7 is set so as to have the current value during trickle charging. Set the current value for normal charging to a value such that the sum of the currents flowing through R7 and R6 is the current value for normal charging.

At the time of rapid charging, the sum of the currents flowing through R7 and R5 is set to be the rapid charging current value. The charge mode display lights up when D8 is fast charging. D9 lights up during normal charging. D 10 lights up during trickle charging. Reference numeral 8 denotes a timer circuit, which is set to the charging time at the time of rapid charging, and makes the switching transistor 5 non-conducting when the time elapses. Reference numeral 9 is also a timer circuit, and the timer time is set to the charging time of normal charging, and after a lapse of time, the switch transistor of 6 is turned off.

[0011]

[Effect of the device]

 According to the present invention, since it is possible to charge the Ni-cd battery according to the residual capacity value, overcharging is prevented and the battery life can be extended.

[Brief description of drawings]

FIG. 1 is a block diagram of a charger according to the present invention.

FIG. 2 is a block diagram of a conventional charger. T is a power transformer S is a power switch 1 is a rectifier. 2 is a switch transistor. 3 is a timer circuit. R1 and R2 are constant current setting resistors. D1 and D2 are backflow prevention diodes. BT is a Ni-cd battery

[Explanation of symbols]

 T power transformer S power switch 1 rectifier 4,8,9 timer circuit 5,6 switch transistor circuit 10,11,12 RS type FF (flip-flop) 13,14,15 comparator circuit 16 relay R5, R6, R7 constant current Setting resistors D1, D2, D3 Backflow prevention diodes D8, D9, D10 Display light emitting diodes R8, R9, R10 Light emitting diode current setting resistors

Claims (1)

[Scope of utility model registration request] 1. A charger for charging a Ni-cd battery, for resistors (R5, R6, R7) for determining current values of trickle charge, normal charge and quick charge, and a switch for selecting one of the above three charging methods. A transistor circuit (5, 6), a timer circuit (4) that operates for a certain time before charging, a relay (16) that operates by the output of the timer circuit, and a resistor (R11 that becomes a load of a Ni-cd battery when the relay operates). ),
Three comparators (13, 14, 15) for judging the voltage of the Ni-cd battery when the load resistance is connected and a flip-flop (1 for storing the output of each comparator)
0, 11, 12) and a display circuit for displaying three types of charging as constituent elements, and at the start of charging, a timer circuit (4)
Actuates the relay (16), and at the relay contact Ni-cd
Flip-flops (10, 11 ,,) for storing the output of each comparator by connecting a load resistor (R11) to the battery or connecting a comparator (13, 14, 15) to this load resistor
A charger characterized by controlling a transistor circuit for a switch that selects a charging method in 12).