Ni-mh nickel-cadmium cell group charger control circuit
Technical field
The utility model relates to a kind of charger control circuit, especially a kind of ni-mh nickel-cadmium cell group charger control circuit.
Background technology
Ni-MH battery has that volume is little, capacity is big, memory effect is little, security performance is good and need not advantage such as baffle during the environmental protection combination, just is being widely used in fields such as electronic dictionary, digital camera, remote-control car, telecontrolled aircraft, electrokinetic cell.Nickel-cadmium cell has, and but macrocell discharges and recharges, security performance is good, combination the time need not advantages such as baffle, and shortcoming is that memory effect is arranged, not environmental protection.But some needs heavy-current discharge instrument still need use nickel-cadmium cell, needs the occasion of heavy-current discharge as instrument such as portable phone, portable electric saw and some other.Therefore, designing the charger that is suitable for ni-mh, nickel-cadmium cell group is trend of the times.
Present NI-G, Ni-Cd battery charger control circuit have the following disadvantages: (1) needs the artificial control charging interval, causes that the battery heating tape comes disaster hidden-trouble otherwise overcharge easily, uses very inconvenience; (2) charging voltage and electric current are fixed, and can not select as required; (3) temperature rise of battery is difficult to control in the charging process; (4) charger produces electrical network and disturbs.
The utility model content
At the deficiencies in the prior art, problem to be solved in the utility model provide a kind of applicable to ni-mh, nickel-cadmium cell group, the controlled quick charger control circuit of the selectable pulsed of charging current.
For addressing the above problem the following technical scheme that the utility model adopts:
The utility model comprises civil power input converted to be decided voltage and decide power circuit and the charge management circuit that current DC is exported, and the charger control circuit power circuit is made of AC input, electromagnetic compatibility element, input rectifying filter circuit, pulse-width modulation circuit, regulating circuit, output rectifier and filter, constant-current constant-voltage circuit and feedback circuit.After being electrically connected successively, AC input, electromagnetic compatibility element and input rectifying filter circuit output to pulse-width modulation circuit and regulating circuit respectively, the output of regulating circuit successively with output arrangement filter circuit, decide voltage constant-current circuit, feedback circuit and pulse-width modulation circuit and be electrically connected, after pulse-width modulation circuit is handled input, export to regulating circuit, behind output rectifier and filter, provide input again for charge management circuit.
Wherein: charger control circuit electromagnetic compatibility element mainly comprises successively fuse F1, thermistor THR01, differential mode inductance LF1, surge absorber ZNR1 and the common mode inductance LF2 of the capacitor C Y1, the capacitor C Y2 that are electrically connected, capacitor C X1, overcurrent open-circuit-protection.
Wherein: charger control circuit input rectifying filter circuit mainly is electrically connected by bridge heap BD1 and big capacitor C 1 to be formed.
Wherein: the charger control circuit pulse-width modulation circuit comprises the resistance R 14 and the capacitor C 8 of chip IC 1, current sense resistor R18, voltage stabilizing didoe ZD1, overcurrent protection.
Wherein: the charger control circuit regulating circuit comprises pulse transformer T1, switching tube Q01, diode D1, filter capacitor C4, filter capacitor C3 and resistance R 3, wherein the output winding of charger control circuit pulse transformer T1 is two groups, links to each other with single-chip microcomputer IC103 with chip IC 102 through output rectifier and filter respectively; The power supply winding is electrically connected with capacitor C 4, chip IC 1 successively through diode D1; Elementary winding is electrically connected successively with capacitor C 3 and resistance R 3; Switching tube Q01 is connected with current monitoring resistance R 18 with chip IC 1, pulse transformer T1 power supply winding respectively.
Wherein: the charger control circuit output rectifier and filter comprises rectifying tube D101, rectifying tube D102, filter capacitor C104, filter capacitor C105, filter capacitor C101, voltage stabilizing chip IC 101 and filter inductance L101, wherein: rectifying tube D101, filter capacitor C104, filter capacitor C105 and filter inductance L101 are electrically connected successively with one group of output winding of pulse transformer T1, and rectifying tube D102, filter capacitor C101 and voltage stabilizing chip IC 101 are electrically connected successively with another group output winding of pulse transformer T1.
Wherein: charger control circuit is decided the switch SW 1 that the voltage constant-current circuit mainly comprises chip IC 102, output current detection resistance R 104 and can be adjusted into the required electric current of arbitrary two retainings, and wherein chip IC 102 links to each other with voltage-stabiliser tube IC104 and pulse transformer T1 output winding through the AK of optocoupler U1 level respectively; Output current detects resistance R 104 and links to each other with the charging earth terminal with pulse transformer T1 output winding respectively, and switch SW 1 links to each other with voltage-stabiliser tube IC104 with chip IC 102 respectively.
Wherein: the charger control circuit feedback circuit mainly is made of optocoupler U1, and optocoupler U1 links to each other with chip IC 1 with chip IC 102 respectively.
Wherein: the charger control circuit charge management circuit comprises single-chip microcomputer IC103, transistor switch Q101, resistance R 115, resistance R 116 and LED A, LED B, and wherein transistor switch Q101 links to each other with single-chip microcomputer IC103 with pulse transformer T1 output winding respectively.
Wherein: charger control circuit Charge Management device also comprises external and place the thermistor NTC of rechargeable battery with charger control circuit single-chip microcomputer IC103.
AC input is through the EMC element filters, obtains the direct voltage of low chain ripple and noise again through over commutation and big capacitor filtering.Direct voltage starts pulse-width modulation circuit, starts the pulse transformer T1 of regulating circuit simultaneously.T1 level output of transformer is respectively through obtaining direct current output after rectifying tube D101, rectifying tube D102 rectification, output filter capacitor C101, filter capacitor C104, the filter capacitor C105 filtering.One tunnel output feeds back to elementary pulse-width modulation circuit through deciding voltage, constant-current circuit by optocoupler U1, and pulse-width modulation circuit is regulated the duty ratio of transformer T1, reaches to decide the purpose that voltage is decided electric current output.The stable output voltage in another road is given single-chip microcomputer IC103 power supply simultaneously, and when this charger is connected to correct battery pack, single-chip microcomputer IC103 detects correct voltage, can voltage be set automatically according to battery pack.Conducting and the shutoff of single-chip microcomputer IC103 control switch transistor Q101: when filling soon, charge the battery in the pulse current charge mode, reduced the temperature rise of battery in charging process greatly, single-chip microcomputer IC103 lights red light emitting diodes LEDA simultaneously.When single-chip microcomputer IC103 detect-Δ V after, think that battery pack filled fullly, single-chip microcomputer IC103 transfers charge mode to trickle charge by filling soon, red light emitting diodes LEDA extinguishes, green LED LEDB lights, the expression battery has filled full.At this moment, can take off battery pack at any time.Single-chip microcomputer IC103 establishes the overheat protector pin in addition; but the temperature rise of external thermistor NTC monitoring battery group is when the temperature rise of battery pack surpasses 55 ℃, single-chip microcomputer IC103 control switch transistor Q101; make charger enter the trickle charge state, reach the purpose of protection battery pack.Charger also has current selected switch SW1, can be according to the selected charger current of battery capacity.
Owing to adopt above scheme, the utlity model has following advantage:
1. the Ni-MH/Ni-Cd battery pack scope that can fill is wide;
2. powerful electromagnetic compatibility element greatly reduces the interference of charger to electrical network;
3. the fast mold filling formula of pulsed has reduced the temperature rise of battery pack in charging process;
4. counter filling and the reverse connecting protection function;
5.-filling full and do not have satiety, Δ V and 0 Δ V detecting, assurance battery 100% produce
6. can output voltage be set automatically according to the voltage of battery pack;
7. electric current can be selected;
8. overheat protector function.
Description of drawings:
Fig. 1 is the utility model schematic block circuit diagram;
Fig. 2 is the utility model circuit diagram.
Embodiment
Below in conjunction with accompanying drawing the utility model is described further:
As shown in Figure 1, the utility model is made of power circuit and charge management circuit.Power circuit comprises AC input, electromagnetic compatibility element (EMC), input rectifying filter circuit, regulating circuit, pulse-width modulation circuit, output rectifier and filter again, decides electric current, fixed voltage circuit.Charge management circuit mainly is made of switch Q101 and single-chip microcomputer IC103 control, and switch Q101 is a transistor, single-chip microcomputer IC103 Samsung S9444.
Power circuit is mainly used to civil power input converted to be decided voltage, decide current DC and exports, and promptly provides stable, safe power supply to charge management circuit, thereby guarantees the work that charge management circuit is more stable, safe.As shown in Figure 2, the electromagnetic compatibility element is mainly by X capacitor C XI, Y capacitor C Y1, Y capacitor C Y2, and differential mode inductance LF1, common mode inductance LF2 form; The input rectifying filter circuit mainly is made up of bridge heap BD1 and big capacitor C 1; Pulse-width modulation circuit is mainly controlled the duty ratio of regulating circuit by chip IC 1 (UC3843); Regulating circuit mainly is made of pulse transformer T1; Output rectifier and filter is made of rectifying tube D101, rectifying tube D102, output filter capacitor C101, filter capacitor C104, filter capacitor C105 and filter inductance L101; Deciding voltage decides electric current and is controlled by chip IC 102 (LM358); Feedback circuit is mainly finished under the fellowship of chip IC 102 (LM358) and chip IC 1 (UC3843) by optocoupler UI.
The AC input is through Y capacitor C Y1, Y capacitor C Y2 filtering, through fuse F1, thermistor THR01, differential mode inductance LF1, surge absorber ZNR1, common mode inductance LF2 and X capacitor C X1.Fuse F1 mainly plays the effect of overcurrent open circuit, and when charger caused input current to increase owing to fault, fuse F1 open circuit played a protective role.Input impulse current when thermistor THR01 reduces cold start-up.Differential mode inductance LF1, capacitor C X1, common mode inductance LF2 can prevent the interference effect electrical network that charger produces.High voltage seals in the destruction charger thereby surge absorber ZNR1 prevents the AC input.The AC input is through flowing into bridge heap BD1 rectification behind the said elements, big capacitor C 1 filtering obtains direct voltage, and direct voltage provides starting resistor and electric current for the chip IC 1 (UC3843) of pulse-width modulation circuit through resistance R 1, resistance R 5, resistance R 6.Start moment, the 6 pin output high level of chip IC 1, switching tube Q01 conducting, pulse transformer T1 excitation.Give the 7 pin power supply of chip IC 1 after transformer T1 power supply winding process rectifying tube D1 rectification, the filter capacitor C4 filtering, pulse-width modulation circuit enters normal work stage.Pulse transformer T1 secondary winding output matrix square wave, output winding 1 is given chip IC 102 (LM358) power supply through rectifying tube D101 rectification, capacitor C 104, filter capacitor C105 and inductance L 101 filtering, starts fixed voltage circuit.Output voltage enters voltage-stabiliser tube IC104 (TL431) through resistance R 105, and to obtain precision be 1% 2.5V voltage, and 2.5V voltage is as the reference voltage of chip IC 102 (LM358) 3 pin voltages.Another road of output voltage enters chip IC 102 (LM358) 2 pin through resistance R 106, resistance R 109 dividing potential drops.When output voltage is too high, when promptly 2 pin voltages are higher than 2.5V, chip IC 102 (LM358) output low level, the AK level of optocoupler U1 flows through electric current, and this electric current feeds back to pulse modulated circuit chip IC 1 (UC3843) 2 pin through optocoupler U1.2 pin voltage step-downs, chip IC 1 (UC384 3) output duty cycle reduces, and output voltage reduces.Otherwise, cross when low as input voltage, 2 pin voltages are lower than 2.5V, chip IC 102 (LM358) 1 pin output high level, and the AK level no current of optocoupler U1 flows through, no feedback signal, 2 pin voltages uprise, and chip IC 1 (UC3843) output duty cycle increases, and output voltage increases, pulse modulated circuit, feedback circuit and fixed voltage circuit are exactly by above mode, reach the effect of regulated output voltage.
In the primary wire, diode D1, capacitor C 3, resistance R 3 absorbs pulse transformer T1 leakage inductances and the peak voltage that produces, protection switch pipe Q01.R18 is a current sense resistor, and when the peak voltage that flows through resistance R 18 surpassed 1V, chip IC 1 (UC3843) was turn-offed, thereby plays the effect of restriction input current.Resistance R 14 is formed the overcurrent protection screen packs with capacitor C 8, avoids reason such as noise to cause chip IC 1 (UC3843) misoperation.Voltage-stabiliser tube ZD1 plays output overvoltage, and when feedback goes wrong and when causing output voltage to raise, voltage-stabiliser tube ZD1 conducting makes chip IC 1 (UC3843) 3 pin voltages be higher than 1V, pulse modulated circuit turn-offs, thereby reaches the purpose of overvoltage protection.Voltage stabilizing chip IC 101 (7805) is passed through in the 2 process rectifying tube D102 rectifications of pulse transformer T1 output winding, capacitor C 101 filtering again, give single-chip microcomputer IC103 (S9444, the core of Charge Management) provides stable 5V power supply, single-chip microcomputer IC103 (S9444) is in case energising, its 3 pin and 5 pin are each 2 times output high level alternately, output low level then, red light emitting diodes LEDA and green LED LEDB alternately glimmer and put out after 2 times.At this moment, expression power circuit and charge management circuit have performed charging and have prepared, and only need to connect battery at output.When the detected cell voltage of single-chip microcomputer IC103 (S9444) 7 pin correct, its 2 pin output matrix square wave, the high level of 3 pin output simultaneously, red light emitting diodes LEDA lights, charger with the pulsed fast charge mode to battery charge.After connecting battery, constant-current circuit will start, and guarantee that charger charges the battery with stable electric current.
The operation principle of deciding electric current is as follows: precision is that 1% 2.5V reference voltage provides electric current, reference voltage for chip IC 102 (LM358) 5 pin through resistance R 111, resistance R 110 and resistance R 113.R104 is that output current detects resistance, when resistance R 104 detected voltages are higher than chip IC 102 (LM358) 5 pin voltages, 7 pin output low levels, this signal feeds back to elementary pulse modulated circuit through optocoupler U1, recently reaches the purpose that stabling current is exported by regulating duty.In the constant-current circuit course of action, fixed voltage circuit is in off position fully.Because constant-current circuit has increased switch SW 1, can be adjusted into the required electric current of any second gear so decide electric current.
When single-chip microcomputer IC103 (S9444) 7 pin detect-Δ V battery has filled fullly, its 2 pin output low level transfers to battery pack is carried out the trickle charge state.The high level of single-chip microcomputer IC103 (S9444) 5 pin output simultaneously, green LED LEDB lights, and it is full to show that battery has filled, can take off battery at any time and use.
When the battery reversal connection, because single-chip microcomputer IC103 (S9444) 7 pin detect negative voltage, its 2 pin output low level, not conducting of switching tube Q101, charger is not given batteries charging, has played anti-effect of filling protection effectively.When not connecing AC power supplies during the reversal connection battery and since single-chip microcomputer IC103 (S9444) not electric, its 2 pin output low level, not conducting of switching tube Q101, the effect of reverse connecting protection has been played in battery discharge off loop effectively.
The utility model also has the overheat protector function except that above function.Single-chip microcomputer IC103 (S9444) 6 pin are that overheat protector detects pin; NTC is external thermistor; during charging; thermistor NTC is inserted in the battery pack, be higher than 55 ℃ when thermistor NTC detects battery pack temperature, the resistance of thermistor NTC will be lower than 3.3K; the 6 pin voltages of single-chip microcomputer IC103 (S9444) will be lower than 1.25V; its 2 pin output low level makes charger enter the trickle charge state, thereby plays the overheat protector effect.