CN104882915B - Lithium battery charging circuit and lamps and lanterns - Google Patents

Lithium battery charging circuit and lamps and lanterns comprising: the first regulated power supply；First comparator, out-phase end connect the first regulated power supply；Controlled switch comprising the control terminal at control terminal, first switch end and second switch end, the controlled switch connects the output end of the first comparator；Detection resistance, string are located between the in-phase end of the first comparator and the second switch end of controlled switch；Switch module, the control terminal of the switch module connect the first switch end of the controlled switch, and the input terminal of the switch module connects charge power supply, and the output end of the switch module connects lithium battery；Wherein, which is converted to sampled voltage charging current, which compares the sampled voltage and reference voltage controls the controlled switch, which controls the switch module and open under the conditions of the electric quantity of lithium battery is insufficient.The present invention can be detached from the dependence to dedicated charger, can be charged to battery using common power, and safe and reliable.

Lithium battery charging circuit and lamps and lanterns

Technical field

The present invention relates to charging circuit more particularly to lithium battery charging circuits and lamps and lanterns.

Background technique

Existing rechargeable battery charges usually using integrated chip and controls, using three stage charging system.Flashlight, searchlighting The in-built electricals pool such as lamp lamps and lanterns are usually using the charger with automatic charge control function, as long as in battery-end series diode Prevent polarity reversed, lamps and lanterns itself do not have charging and detect and control function, to the entire charging process of battery all by External matching charger is completed.Cause lamps and lanterns excessively to rely on dedicated charger in this way, if mating battery charger failure, uses Common power cannot charge to lamps and lanterns, make troubles to using.

Summary of the invention

The technical problem to be solved in the present invention is that overcoming above-mentioned the shortcomings of the prior art, and propose a kind of lithium battery Charging circuit and lamps and lanterns are able to solve lamps and lanterns charging in the prior art and excessively rely on external charger and bring charging inconvenient The problem of.

In order to solve the above technical problems, the present invention proposes a kind of lithium battery charging circuit comprising: the first regulated power supply, It is used to provide an adjustable voltage；First comparator, out-phase end connect the first regulated power supply；Controlled switch, packet Control terminal, first switch end and second switch end are included, the control terminal of the controlled switch connects the output end of the first comparator； Detection resistance, string are located between the in-phase end of the first comparator and the second switch end of controlled switch；Switch module, Including control terminal, input terminal and output end, the control terminal of the switch module connects the first switch end of the controlled switch, this is opened The input terminal for closing module connects charge power supply, and the output end of the switch module connects lithium battery；Wherein, the detection resistance is charging Electric current is converted to sampled voltage, which compares the sampled voltage and reference voltage controls the controlled switch, The controlled switch controls the switch module and opens under the conditions of the electric quantity of lithium battery is insufficient.

Preferably, which further includes a current-limiting resistance, which is located at the first comparator Output end and controlled switch control terminal between.

Preferably, which includes divider resistance and the first adjustable resistance, the divider resistance and first Adjustable resistance is connected between a stabilized power source and ground, and the tap terminals of first adjustable resistance connect the reverse phase of the first comparator End.

Preferably, the resistance value of the detection resistance is 1 Ω.

Preferably, which includes first switch tube, second switch and first resistor, the first switch tube with And second switch includes control terminal, input terminal and output end；The control terminal of the second switch connects the switch module Control terminal, the input terminal of the second switch connects the control terminal of the first switch tube, the output end of the second switch with And the output end of the first switch tube is connected, which is located at the input terminal and second switch of the first switch tube Control terminal between, the input terminal of the first switch tube connects the input terminal of the switch module, the output end of the first switch tube Connect the output end of the switch module.

Preferably, which is PNP triode, and the base stage of the PNP triode is the control of the first switch tube End, the input terminal of the transmitting extremely first switch tube of the PNP triode, the current collection of the PNP triode extremely first switch The output end of pipe, the second switch are NPN triode, and the base stage of the NPN triode is the control terminal of the second switch, should The input terminal of the current collection of the NPN triode extremely second switch, the transmitting extremely second switch of the NPN triode it is defeated Outlet.

Preferably, which further includes cue module, which includes the second regulated power supply, second Comparator, the first sampling resistor, the second sampling resistor, red LED lamp and green LED lamp；First sampling resistor and Two sampling resistor strings are located between the positive and negative anodes of the lithium battery, the positive terminal of second comparator connect first sampling resistor with And second sampling resistor junction, which compares voltage and second adjustable electric on second sampling resistor The red LED lamp is controlled after the reference voltage in source to shine in the electric quantity of lithium battery deficiency, controls the green LED lamp when being full of It shines.

Preferably, which further includes power module, which includes decompression chip, the decompression core The input terminal of piece connects the charge power supply, which exports the stabilized power source.

The present invention also proposes a kind of lamps and lanterns comprising lithium battery charging circuit as described above.

Compared with prior art, the invention has the following beneficial effects: lithium battery charging circuit of the invention and lamps and lanterns, By using comparator and switch module, it can be realized the automatic detection control to lamps and lanterns charging and adjust, avoid lithium electricity Dedicated charger is excessively relied on when pond is charged and in lamps and lanterns use process, can be charged the battery using common voltage source, And it is safe and reliable, in the occasion that the Portable lighting device or reserve battery of built-in rechargeable lithium battery charge, have practical Application value.

Detailed description of the invention

Fig. 1 is the circuit diagram of lithium battery charging circuit of the invention.

Description of symbols: divider resistance R2 the first adjustable resistance RT1 first comparator U1A current-limiting resistance R1 is controlled 1 first switch tube Q1 second switch Q2 first resistor R1 cue module 2 of switch Q3 detection resistance RS1 switch module 8th resistance R8 the second adjustable resistance RT2 the second comparator U1B the first sampling resistor RC1 the second sampling resistor RC2 instruction The 5th switching tube Q5 of the 5th the 7th the 4th switching tube Q4 of resistance R7 of resistance the 6th resistance R6 of R5 of the 4th resistance R4 of unit 21 3 first filter capacitor C4 the second filter capacitor C5 of red LED lamp D4 green LED lamp D3 power module is depressured chip U2.

Specific embodiment

Principle and structure in order to further illustrate the present invention carry out the preferred embodiment of the present invention now in conjunction with attached drawing detailed It describes in detail bright.

Lithium battery charging circuit embodiment

Referring to Fig. 1, a kind of lithium battery charging circuit comprising: the first regulated power supply, controlled is opened first comparator U1A Close Q3, detection resistance RS1, current-limiting resistance R1, switch module 1, cue module 2 and power module 3.

First regulated power supply is used to provide an adjustable reference voltage.First comparator U1A, out-phase end connect Connect the first regulated power supply.Controlled switch Q3 comprising control terminal, first switch end and second switch end, controlled switch Q3 Control terminal connect the output end of first comparator U1A.Detection resistance RS1, string are located at the same phase of first comparator U1A Between end and the second switch end of controlled switch Q3.Current-limiting resistance R1 string be located at the output end of first comparator U1A with And between the control terminal of controlled switch Q3.

Switch module 1 comprising control terminal, input terminal and output end, it is controlled that the control terminal of the switch module 1 connects this The first switch end of switch Q3, the input terminal of the switch module 1 connect charge power supply, and the output end of the switch module 1 connects lithium Battery.

Wherein, charging current is converted to sampled voltage by detection resistance RS1, and first comparator U1A compares the sampling Voltage and reference voltage control controlled switch Q3, and controlled switch Q3 controls the switch module 1 in the lithium battery Measure it is insufficient under the conditions of open.

First regulated power supply includes: divider resistance and the first adjustable resistance.The divider resistance and the first adjustable electric Resistance is connected between a stabilized power source and ground, and the tap terminals of first adjustable resistance connect the reverse side of first comparator U1A. By adjusting the size of the adjustable reference voltage of resistance value of the first adjustable resistance, so that it is determined that the size of charging current.

In the present embodiment, the resistance value of detection resistance RS1 is 1 Ω.The resistance value of current-limiting resistance R1 is 100 Ω.

The switch module 1 includes first switch tube Q1, second switch Q2 and first resistor R1, first switch tube Q1 And second switch Q2 includes control terminal, input terminal and output end.The control terminal of second switch Q2 connects this and opens The control terminal of module 1 is closed, the input terminal of second switch Q2 connects the control terminal of second switch Q2, the second switch The output end of the output end of Q2 and first switch tube Q1 are connected, and first resistor R1 string is located at the defeated of first switch tube Q1 Between the input terminal for entering end and second switch Q2, the input terminal of first switch tube Q1 connects the input of the switch module 1 End, the output end of first switch tube Q1 connect the output end of the switch module 1.

In the present embodiment, first switch tube Q1 is PNP triode, and the base stage of the PNP triode is the first switch tube The control terminal of Q1, the transmitting extremely input terminal of first switch tube Q1 of the PNP triode, the current collection of the PNP triode is extremely The output end of first switch tube Q1.Second switch Q2 is NPN triode, and the base stage of the NPN triode is that this second is opened Close the control terminal of pipe Q2, the current collection of the NPN triode extremely input terminal of second switch Q2, the transmitting of the NPN triode The extremely output end of second switch Q2.The PNP triode and NPN triode constitute darlington structure, make the control of circuit It makes safer.

The cue module 2 includes: the second regulated power supply, the second comparator U1B, the first sampling resistor RC1, the second sampling electricity Hinder RC2, red LED lamp D4, green LED lamp D3, the 4th resistance R4, the 5th resistance R5, the 6th resistance R6, the 7th resistance R7, the Four switching tube Q4 and the 5th switching tube Q5.

The first sampling resistor RC1 and the second sampling resistor RC2 string is located between the positive and negative anodes of the lithium battery, this second The positive terminal of comparator U1B connects the junction of the first sampling resistor RC1 and the second sampling resistor RC2, this second compares Device U1B controls the red LED after comparing the reference voltage of voltage and second regulated power supply on second sampling resistor RC2 Lamp D4 in the electric quantity of lithium battery deficiency shine, control green LED lamp D3 full of when shine.4th resistance R4 is connected to Between the output end of the control terminal of four switching tube Q4 and the second comparator U1B.5th resistance R5 be connected to a stabilized power source with And the 4th switching tube Q4 input terminal between.6th resistance R6 and green LED lamp D3 is sequentially connected in series in stabilized power source and Between the input terminal of four switching tube Q4.The control terminal of 5th switching tube Q5 connects the input terminal of the 4th switching tube Q4, the 7th resistance R7 is connected between the input terminal of stabilized power source and the 5th switching tube Q5.The anode of red LED lamp D4 connects green LED lamp D3 Anode, the cathode of red LED lamp D4 connects the input terminal of the 5th switching tube Q5.

In the present embodiment, the second regulated power supply includes: the 8th resistance R8 and the second adjustable resistance RT2.8th resistance R8 And second adjustable resistance RT2 be connected between stabilized power source and ground.Wherein, the tap terminals connection the of the second adjustable resistance RT2 The reverse side of two comparator U1B, and provide reference voltage by way of partial pressure and give second comparator U1B.

In the present embodiment, the 4th switching tube Q4 is NPN triode, and the base stage of NPN triode is the control of the 4th switching tube Q4 End processed, the current collection of the NPN triode extremely input terminal of the 4th switching tube Q4, the transmitting of NPN triode extremely the 4th switching tube Q4 Output end.In other embodiments, NPN triode can be replaced with metal-oxide-semiconductor.

In the present embodiment, the 5th switching tube Q4 is NPN triode, and the base stage of NPN triode is the control of the 5th switching tube Q4 End processed, the current collection of the NPN triode extremely input terminal of the 5th switching tube Q4, the transmitting of NPN triode extremely the 5th switching tube Q4 Output end.In other embodiments, NPN triode can be replaced with metal-oxide-semiconductor.

Power module 3 includes: the first filter capacitor C4, the second filter capacitor C5 and decompression chip U2.First filtering Capacitor C4 is connected between the input terminal and ground of decompression chip U2, and second filter capacitor C5 is connected to the output of decompression chip U2 Between end and ground, the input terminal of decompression chip U2 is connected through the voltage VV of the charge power supply after rectifying and wave-filtering, is depressured chip U2 Output end export a stabilized power source VCC.Stabilized power source is powered to first comparator U1A and the second comparator U1B, is also used for The output of power supply as first comparator U1A and the second comparator U1B.

In the present embodiment, the resistance value of the model LM393 of first comparator U1A, current-limiting resistance R1 are 100 Ω, the second electricity The resistance value for hindering R2 is 100K Ω, and the resistance value of the first adjustable resistance RT1 is 10K Ω.The model LM393 of second comparator U1B, the The resistance value of two sampling resistor RC2RS2 is 10K Ω.The resistance value of 5th resistance R5 is 1K Ω, and the resistance value of the 6th resistance R6 is 500 Ω, The resistance value of 7th resistance R7 is 1K Ω.The model 78L05 of three-terminal voltage-stabilizing pipe U2.

In the present embodiment, the resistance value of the model LM393 of first comparator U1A, current-limiting resistance R1 are 100 Ω, partial pressure electricity The resistance value for hindering R2 is 100K Ω, and the resistance value of the first adjustable resistance RT1 is 10K Ω.The model LM393 of second comparator U1B, the The resistance value of one sampling resistor RC1 is 4.3K Ω, and the resistance value of the second sampling resistor RC2 is 10K Ω.The resistance value of 5th resistance R5 is 1K The resistance value of Ω, the 6th resistance R6 are 500 Ω, and the resistance value of the 7th resistance R7 is 1K Ω.It is depressured the model 78L05 of chip U2.

Carry out the working principle that the present invention will be described in detail below with reference to Fig. 1.

The present invention uses the basic electronics member such as first comparator U1A, the second comparator U1B and triode of wide operating voltage It is 14.8V lithium battery charging circuit that part, which forms voltage rating,.Wherein, single-cell lithium-ion battery voltage rating 3.7V, charging limitation Voltage 4.2V, the present invention is by taking the concatenated lithium ion battery of 4 sections as an example, due between the input terminal and battery of lithium battery charging circuit Two diodes and a triode are bridged, input need to be greater than 18V.The charger can export that 100mA~1A is adjustable to be filled Electric current can be used the 19V power supply on laptop as input for personal use.Charging time is big by the electric current set Small decision.

Before charging, circuit is connected by jump cap JP1 first, the input terminal of lithium battery charging circuit is then connected the notes The power supply port of USB interface originally or other power supplies, input voltage pass through the fuse F1 of 1.5A, and diode D1 is anti-reverse The input terminal of first switch tube Q1 is arrived after protection.Default conditions power tube is conducting, because of the output end of first comparator U1A High level, controlled switch Q3 conducting are exported, the base stage of second switch Q2 is connected because of dragging down.Wherein, at detection resistance RS1 In charging current return ground the only way which must be passed on carry out current limliting.Voltage on first comparator U1A operation acquisition testing resistance RS1 and come From the output electric current of the relatively rear output voltage control switch module of the first centre tapped voltage of adjustable resistance RT1, and always In a fixed current value.Adjust this adjustable charging current of the first adjustable resistance RT1.

Second comparator U1B samples lithium battery voltage, and when battery does not access, the 17.5v voltage of output passes through The center tap voltage of voltage value and the second adjustable resistance RT2 after first sampling resistor RC1, the second sampling resistor RC2 partial pressure After export to the 4th switching tube Q4, green LED lamp D3 brightens at this time.After accessing the charging circuit when dead battery, the The voltage that two sampling resistor RC2 are sampled be lower with the center tap voltage of the second adjustable resistance RT2 relatively after, second compares Device U1B control red LED lamp D4 brightens.After fully charged, the voltage of the second sampling resistor RC2 sampling is greater than reference voltage (the The center tap voltage of two adjustable resistance RT2) when, red LED lamp D4 brightens, and prompts charging complete.But circuit still can be with small electricity The charging modes of stream carry out trickle charge to battery.

Lamps and lanterns embodiment

The present invention also proposes a kind of lamps and lanterns comprising the lithium battery charging circuit being as above somebody's turn to do.

Compared with prior art, the invention has the following beneficial effects: lithium battery charging circuit of the invention and lamps and lanterns, By using comparator and switch module, it can be realized the automatic detection control to lamps and lanterns charging and adjust, avoid lithium electricity Dedicated charger is excessively relied on when pond is charged and in lamps and lanterns use process, can be charged the battery using common voltage source, And it is safe and reliable, in the occasion that the Portable lighting device or reserve battery of built-in rechargeable lithium battery charge, have practical Application value.

The above is only preferable possible embodiments of the invention, not limit the scope of the invention, all with the present invention The variation of equivalent structure made by specification and accompanying drawing content, is included within the scope of protection of the present invention.