DE2351005A1 - CHARGER FOR ACCUMULATORS - Google Patents

Description

R.178?

27 »9 -1973 Ws / Kf

Attachment to
Patent application

ROBERT BOSCH GMBH ₅ Stuttgart

Battery charger

The invention relates to a charging device for accumulators _{s s,} a Ladegleiehrichter with a smoothing element by means of battery terminals to be connected to an 'on = zuladenden accumulator in particular for Pahrzeugbatteriena with a primary side to be connected to an AC voltage source charging transformer of the secondary side over and provided with a loading = lampe is _a the xtf lights up during the charging process »

Such _s as Heiralader known battery chargers have the purpose of charge _s almost goose or partially discharged batteries of automobiles again, "This is motwendigj especially during the cold season, the dark xire'nn at short driving th -jährend the vehicle battery because of the large energy consumption of the electrical loads the vehicle through the Lieht = · the vehicle engine can not adequately wevasn aufgeladeil "bsw reloadable more. Reloading is far more necessary

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I Λ "j JOUD

Iish _£ when the accumulator by prolonged closure of driving seiiges is weakened by the so-called SeIbstsntladung.

Bsi known batter-ieladegeräten illuminated when switched yes charger the charging lamp on "By connecting battery" charging current flows even ,, when it is fully charged ο is He is overweight there and hospitable _s being in his cell in significant water sersetst. The Water = must be refilled after the charger is switched off . In addition, the charger can also be _{overloaded as a result of incorrect operation:} for example, if the battery is connected with the wrong polarity, which may lead to failure of the device, which at least one more discharge of the accumulator "

From companionship ₉ that such devices sum charging b?, V; _t reloading / Jai-tiings free accumulators are unsuitable _c they also have the Mayigel ₅ that the charging lamp also lights up _B when the Ak: -:? jmulator '/ oll is charged or if there is an incorrect operation of the 2srSL "fces =

Bar Er findüiig its object _s the charge lamp of Ladsger-DEVICE ssur display a sc correct charging process on the one hand and 3ur- indication of the beginning and end of charging: -JIS to display a · incorrect operation of the charger such examples "pijl to use a reverse polarity of the accumulator or a course selection of the Ari-s-jiilusskleramen on the other hand »

tore Yiird srfiudungsgemäß achieved thereby that the tray 1 amise π, ϊ'ί aer switching path of a switching element in slektrcnisehen 'Ä * iil is gesühaltet ₅ whose control Streeks a threshold';"- Sri-5C.?. .haiv.sr- . tor a abhär-vri.geri from taxable charging current ^ - ■ --- sign: ^ si: influence ISTC D £ g L "d-5ignal is dsbei ir.

advantageously tapped from an actuator for the charging current strength.

Further details of the invention are explained in more detail using an exemplary embodiment shown in the drawing.

Fig. 1 is a block diagram of the charger according to the invention _see Fig. 2 shows the detailed circuit configuration of the charger and Fig. 3 is a characteristic curve for the functional relation between the charging voltage and the charging current in the whole loading and Verpolungsbereich "

The block diagram of the device shown in FIG. 1 has an alternating current connection 10 ₉ to which a V / andler 11 is connected. Its output 12 carries a smoothed direct current. It is connected to an electronic actuator 13 for influencing the charging current in which its output 14 is led directly to the battery connection 15. _{The connected 9} to be charged accumulator 16 is indicated by dashed lines »The battery connection 15 and thus the charging voltage Ua of the accumulator 16 is fed via a connection 17 to a polarity reversal sensor 18» This consists - as explained in more detail in Fig. 2 - of two anti-parallel connected diodes and its two Outputs 19 and 2o are fed to a voltage sensor 21. At the output 22 of the voltage sensor 21, a control voltage Ux occurs, which is fed to the actuator 13. This control voltage is a function of the charging voltage Ua at the battery connection 15 Converter 11 supplied. The charging control device 23 is activated by the actuator 13 via a connection 24. In this block diagram, the voltage sensor 21 and the polarity reversal sensor 18 connected upstream of it form a setpoint

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encoder 25, through which the charging current Ia from the actuator 13 is continuously adjustable «.

2 shows the exact circuit structure of the charger shown »The alternating current connection Io is over a Safety element 3 © on the primary winding 31a of a charging transformer 31, the secondary winding 31b with the Alternating current connection 32a of a charge leveler 32 is connected is. The charging transformer 31 forms together with the charging equalizer 32 implemented in a jerk circuit and a smoothing capacitor 33 from the converter 11 Pig «, 1. The smoothing capacitor 33" lies between the two direct current outputs 32b and 32c of the charging rectifier 32. These DC outputs are about two Supply lines 3 ^ and 35 each with the charge control device 23 and the voltage sensor 21 are connected. The negative output 32c of the loading leveler 32 is also via the supply line 35 to the input of the actuator 13 connected, which consists of a Darlington transistor unit. The connecting line 35 is over a low-resistance resistor 37 to the emitter of the "

Main Darlington transistor 38 connected. The common collector connection of the pre-transistor 39 and the main transistor 38 of the Darlington transistor unit 36 is connected to the negative pole ¹ Io of the battery terminals, and the control signal Ux of the voltage sensor 21 is fed to the base of the Darlington pre-transistor 39 via a line Hl xv. The emitter of the pre-transistor 39 is connected directly to the base of the main transistor 38 and, via a resistor H2, to the emitter of the main transistor 38. The base of the Darlington pre-transistor 39 is also connected to its collector terminal via a stabilizing capacitor U ~ 5.

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The voltage sensor 21 is provided with a circuit for the output control signal ₉ which is connected via the supply lines 34 and 35 to the output of the charging rectifier 32 and which is formed from a resistor 44, the collector = emitter path of a first control transistor 45 and a further resistor 46 » the control range of this control transistor 45 is connected via the Verpolungssensor 18 to the negative pole 4o of the battery terminals "the Verpolungssensor 18 consists of two anti-parallel connected diodes 47 and 48 _S on the one hand, together with the negative pole 4o of the battery terminals, and on the other hand in each case via a resistor, and 5o are connected to the base of the first control transistor 45. The diode 4 coupled on the anode side to the base of the control transistor 45? of the polarity reversal sensor 18 is connected via a further resistor 51 to the supply line 35 connected to the negative output 32c of the charging rectifier 32. The cathode side with the. The diode 48 coupled to the base of the control transistor 45 is connected via a second resistor 52 to the supply line 34 connected to the positive output 32b of the charge leveler 32. The first control transistor 45 is combined with a second control transistor 53 to form a differential amplifier 54 with a common emitter resistor 44. The base of the second control transistor 53 is connected via a resistor 55 to the common emitter terminal of the differential amplifier 54. The base of the second control transistor 53 is also via a reverse zener diode 5 & to the anode of one diode 4? Verpolungssensors of 18 _s is connected is connected via the resistor 51 and the supply line 35 to the negative terminal 32c of the Ladegleichriehters 32 in connection "via the line 4I, the control

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voltage Ux for the actuator 13 at the second im Steiisrstronicreis of the voltage sensor 21 lying resistance 46 tapped.

The positive output 32b of the charging rectifier 32 is exceeded the connection pipe 3 ^b> directly to the positive terminal of the battery terminals connected βο "The accumulator 14 and the connecting leads 57 and 58 of the charger are indicated by dashed lines"

The charge control device 23 is provided with a charge lamp 61 _s which is connected with the Sehaltstrecke of a switching transistor 62 in series. The control path of the switching transistor 62 can be influenced via a threshold switch 63. The base of the switching transistor 62 is connected to the positive output 32b of the charging rectifier 32 via a resistor Sk- on the one hand The threshold switch is made up of two complementary transistors 67 and 63. The first transistor Sj is connected with its switching path via &<sn resistor 65 to the base of the Switching transistor 62 _s double ο the control path of the first transistor 67 is parallel connected to the switching path of the second transistor 68. The control path of the first transistor 67 and -: - Ii & the switching path of the second lying parallel to it

68 are on the one hand connected with their base-emitter via a resistor 69 to the supply line JA ass positive charge output 32b . j'9r ^ ii: idersts.vid 66 connected to dsr supply ^ r-gsleitung 35 öes 2isga; iven output 32e of the ladsg: i & iciir. '. c "; tirr. 32»

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circuit 7o the tapped to the actuator 13 load signal "supplied to the load signal is in this case a Sigrt ^ ft-voltage tapped off at the resistor k2 ₃ parallel to the control path of the Darlington main transistor 38 of the actuator 13 is connected in shape.

The mode of operation of the charger is illustrated in FIG. 3 illustrated characteristic curve about the functional relationship to the mixing of the charging voltage Ua and the charging current Ia explained. For this purpose, important points in the circuit according to FIG. 2 are also provided with capital letters. The point A lies on the supply line 34 leading to the positive pole 60 »Der Point B lies between the two resistors 49 and 52 »Der lying from A to the base of the first control transistor 45 Point C is at the base of the first control transistor 45 and point D is between the two from C to the other Supply line 35 leading resistors 5o and 51- Der Point E lies on the supply line 35 connected to the negative output 32c of the charging rectifier 32. The point F lies at the negative pole 4o and the point G at the common emitter connection of the differential amplifier 54. -The point H lies at the Base of main Darlington transistor 38 of actuator 13 The point J is finally in the charge control device 23 at the base of the first transistor 67 and the point K on the emitter connection of this transistor.

Is the charger connected with its AC terminal Io to a 22o-volt AC _s so there is at the output of its converter 11 a largely smoothed DC voltage of 22V from 0 First, the function of the charger is now _s describes at a charging voltage Vout of 0 V doho if there is a short circuit between the terminals 4o and 60 ο This corresponds to the voltage Ua 0 on the characteristic curve shown in FIG. 3. In this state, the voltage sensor 21 has two current paths ο The first current path is open

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from point A via resistors 53 ₅ 49 ₃ 5o and 51 to point E and the second current path goes from point A via resistors 44 and 55 »via zener diode 56 and resistor 51 to point E. Terminals 4o and 6o are connected to one another, the diode 48 of the polarity reversal sensor 18 is now parallel to the resistor 52. By appropriately dimensioning the resistors ¹ AS ₃ 5o and 51 öes first current path, the voltage at point C is now at the base of the first control transistor j lifted so far 45 that this largely blocked is "also in this circuit condition by a corresponding Dimensionieruiig of the Zener diode 56 whose Zener voltage is not reached ₉ so that, through the aforementioned second current path, no current can flow, thus also the second control transistor 53 of the Differential amplifier 54 locked. Since the first control transistor 45 is blocked, no current flows from point A via resistor 44, the switching path of control transistor 45 and resistor 46 to point E. As a result, no control voltage Ux occurs at resistor 46, and actuator 13 is consequently still not controlled. At the base of the pre-transistor 39 is consequently the potential of the point E via the resistor 46 so that the pre-transistor 39 and with it the main transistor 38 of the Darlington transistor unit 3δ are blocked. There is therefore no charging current Iy through the terminals 4o and 6o »The diode 47 of the polarity reversal sensor 18 is also blocked, since the point D is in terms of potential at the point E and compared to the point F baw. the point A of the circuit is negative.

If the accumulator 16 to be charged is not completely discharged, a charging voltage Ua of 0.5 to 1.5 Volts the point P is negative compared to the point A. The voltage in point C will also be more negative and the first

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Control transistor 45 is now opened more and more as the charging voltage Ua rises. "A current now flows through resistor 46 and a control voltage Ux now reaches the base of pre-transistor 39 of actuator 13 via line 41" This becomes increasingly conductive and now switches the Main transistor 38 also increasingly in the current-conducting state. It therefore begins to flow via the positive pole So of the charger _9, the battery 16 _S, the negative pole 4o and via the switching path of the main transistor 38, a charging current Ia which increases approximately proportionally to the charging voltage Ua.

Upon reaching the charging voltage UAI from about 1 _S 5 volts of the point P relative to the point A of the circuit become as far negative ₉ that the voltage drop is less than the charging voltage across the resistor 52nd The diode 48 is blocked »The voltage at points B _s C and D is now determined by the current path through the resistors 52 _s 49 _a 5o and 51» With continuously increasing charging voltage Ua, the voltage at point C and thus at the base of the first control transistor 45 is no longer affected _s so that in this area flows 45, a constant current via the switching path of this control transistor ,, of the resistor 46, a constant control voltage Ux generates _s which via the line 41 to the actuator is supplied "the prior transistor 39 and consequently also the main transistor 38 is thereby driven such that _s now a constant independent of _a further increase in the charging voltage Ua charging current Ia to flow through the accumulator 1β via the switching path of the actuator. 13 This "area of the charging characteristic shown in FIG. 3 is required for deeply discharging accumulators.

The charging voltage of the circuit reached a value of about 6 üa2 Voit ₂ vilvd the point P also with respect to the point D negative. The diode Hj of the reverse polarity protection seat 18 is now conductive. As a result, the voltage at point F reaches the point

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D ιιηά pulls the point C via the resistor 5o with "in point D there is now a current distribution _s by also exerting? the diode Hj a current flows, which flows over the switching path of the actuator 18 to point E flows. As a result of this process, the control transistor 45 is opened even more as the charging voltage Ua continues to rise »Sr has a negative current feedback through its emitter resistor, kk , so that the current flowing over its switching path rises almost proportionally to the charging voltage Ua» Correspondingly The control voltage Ux at the collector resistor 46 of the control transistor-crs ^ 5 now also rises proportionally to the charging voltage Ua. The Darlington transistor unit 36 is thereby also opened further and a charging current now flows via the stop section of the actuator 13. Ia, which increases approximately proportionally to the charging voltage Ua ₅ until it reaches the value Ua3 of about 8 ₃ 5 volts »

At a charging voltage Ua3 of about 8 _S 5 volts already, a charging current Ia flows from ea. 1 A ₀ This corresponds to the initial charging current of the charger when connecting a partially discharged battery IOE In this charging current of the Glättungskonöensator is already 33 of the transducer 11 alternately in the charging voltage Oa discharged = at the direct current output of the converter 11 therefore eiiiia pulsating direct voltage occurs. Due to the periodic discharge of the smoothing capacitor 33, the points E uiv ": Qi ¹ SiT circuit are also periodically at the same potential. As a result, the charging current at the switching path of the actuator ..." is periodically interrupted. The effective current strength of the Misc - .. Ones therefore does not increase more "proportional to the charging voltage to ο L & dsl: ennlinis _c in Figure 3, therefore, makes use of the charging voltage Ua3 upwards a wrinkle As with further increasing Ladespannuru 5ie pulsisrs ^ AEE DC voltage at the output of Converter il still .In ::: -. R-ssi-?; 'I: rdsnden time segments di-5 exceeds charging voltage Ua _;

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With the charging voltage Ua4 of about 13 volts, a state is now reached in which the voltage difference between points D and G of the circuit reaches the Zener voltage of the Zener diode 56. This now becomes conductive and a current flows via the second current path with the resistors 44 _s 45 of the Zener diode 56 and the resistor 51 «The potential at the base of the second control transistor 52 is now negative compared to point G and the control transistor 53 is now conductive, an additional current now flows from point A to point 3 of the circuit via its switching path . This increases the voltage drop across the resistor 44 and the point G becomes negative, so that the control transistor 45 is blocked more and more as the charging voltage Ua continues to rise Zener diode 56 and the diode 47 of the polarity reversal sensor l8 is directly coupled to the charging voltage at point F of the circuit and consequently opens the control transistor 53 as the charging voltage increases. The current previously flowing via the contact section of the control transistor 45 is now increasingly conducted via the switching section of the second control transistor 53. The control voltage Ux at the collector resistor 46 of the control transistor 45 is thereby reduced and the pre-transistor 39 and with it the main transistor 38 of the Darlington transistor unit 36 are increasingly controlled into the blocking range via the line 41.

At a charging voltage Ua6 of approximately 14 _S 7 volts, the first control transistor 45 is almost completely blocked. The control voltage Ux at the resistor 46 is therefore almost 0 volts. The actuator 13 is not activated and the switching path of the main

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transistor 38 is consequently also blocked. The accumulator 16 is now fully charged. There is no charging current, like this that a water decomposition in the battery is not possible. That The charger is therefore particularly suitable for charging maintenance-free accumulators.

If the battery is connected with reverse polarity, the potential at the negative pole ^ o of the circuit is positive compared to the potential on the positive pole 60. The point P of the circuit is therefore positive compared to the point A and the diode ^ 8 of the polarity reversal sensor 18 is therefore conductive. A current now flows via the diode 48 and via a current path with the resistors U9> 5 ° and 51 to point E and from there via the supply line 35, the charging rectifier 32 and the supply line 3 ^ back to the accumulator l6. Another current path is established through resistor 52 between points A and B of the circuit. As a result of this current, point B becomes positive compared to point A and point C is also raised compared to point G. The control transistor ^ 5 is therefore completely blocked in the entire voltage range when the battery is closed with reversed polarity. A control voltage Ux thus also occurs at the resistor kS , so that the actuator 13 also remains completely blocked.

The discharge current shown in FIG. 3 with a battery connected with reverse polarity is the current flowing through the diode H 8 of the polarity reversal sensor 18. Although it increases as a function of the voltage of the rechargeable battery connected to the verpoit, it is limited to a maximum of around 20 mA by suitable dimensioning of the resistors ** 9> 50, 51 and 52. This low discharge current practically does not load the battery connected with reverse polarity at all.

To avoid operating errors on the charger, this is equipped with the loading control device 23. The charging lamp

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6l is only switched on when the charger is connected to the Accumulator 16 is actually charged by a charging current Ia. It is switched by a signal voltage Us which Via the control line 7o to the high-resistance resistor 42 of the Actuator 13 is tapped. For this purpose, the signal voltage Us must switch on the charging lamp 61 when it is on the control path of the main transistor 38 of the actuator reaches the threshold voltage; d. H. if over the switching path of the main transistor 38 a charging current Ia begins to flow. This is achieved with the threshold switch 63, the Switching transistor 62 controls the charging lamp 6l.

When the actuator 13 of the charger is blocked, the transistor 68 of the threshold switch 63 is conductive because its emitter is connected to the positive output 32d of the charging rectifier 32 via the resistor 69 and its base via the control line Jo and the resistors 42 and 37 of the actuator 13 is connected to the negative output 32c of the charging rectifier 32 via the supply line 35. A current now flows from point A via resistor 69, via the switching path of this transistor 68 and via resistor 66 to point E of the circuit. The potential difference between the points J and K of the threshold switch 63 is determined by the conductive switching path of the transistor 68. It is so small that transistor 67 is blocked. The switching transistor 62 is thus also blocked and the charging lamp 6l is switched off. The base current of the transistor 68 is so small that the voltage drop occurring across the resistor 42 of the actuator is too small to control the main transistor 38.

As soon as the actuator 13 is controlled via the line 4 Γ from the voltage sensor 21, and a charging current Ia to flow

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begins, the potential in point H of the actuator 13 is raised and the increasing signal voltage Us on the control line 7o reaches the value of the threshold voltage at point K, which drops across the threshold resistor 66. The transistor 68 begins to lock. This increases the voltage between points J and K and opens transistor 67. Now flows through the resistors 64, 65 and and the switching path of the transistor 67 and the resistor 66 another current from point A to point E of the circuit. The potential at the base of the Switching transistor 62 therefore becomes negative and its emitter-collector tecke becomes conductive. This is when the charging current begins the charging lamp 6l switched on.

After the end of the charging of the accumulator 16, the charging current Ia goes back to zero, in that the pre-transistor 39 and the main transistor 38 of the actuator 13 - as previously described - is blocked by the voltage sensor 21. The signal voltage Us on the line now falls below the threshold voltage at the threshold resistor 66. Since the emitter of the In terms of potential, transistor 68 via the control path of transistor 67 is only slightly above the threshold voltage at point K is, the control path of the transistor 68 is now conductive again. The voltage between points J and K of the circuit decreases and the transistor 67 again enters the blocking range. The current through resistors 64 and 65 is thereby interrupted and the base of the switching transistor 63 raised again in terms of potential, so that this transistor also locks and the charging lamp 61 turns off. The charging lamp 6l therefore indicates by going out that the charging process has ended is.

If the battery is connected with reverse polarity, the charging lamp 6l also remains switched off, since the actuator 13 - as explained above - is blocked and thus no signal voltage Us reaches the charging control device 23 via the line 7o. The transistor 68 therefore remains conductive and the transistors 67 and 62 remain blocked.

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The invention is not limited to the embodiment, since the structure of the charge controller 23 can be modified can. It is essential to the invention, however, that the charging lamp is switched by a controllable charging current. The Ladelainpe should only light up during the charging process and thus indicate the beginning and the end of the charging process or when switching on of the charger to a polarity reversal of the accumulator or to a short circuit of the battery terminals do "by not lighting it up.

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Claims (2)

" ^1β " 17 Expectations 17 8? ' Charger door accumulators ;, particularly for vehicle battery ^ with sinsa prdmärseitig to be connected to an AC voltage source charging transformer sekundärssitig to rope left in a charged accumulator via a Ladegleiehriehter with a Glattungsglied means of battery terminals and which is provided with a LadelaiHps ₅ which is illuminated during the charging process j characterized _s that the charging lamp (61) rushes the Sehaltstrecke an electronic switching element (52) is connected in series, whose control path is linked via a Schwel switch (63) of a controllable charging current (Ia) dependent charging signal (Us) to influence is, 2. Charger according to claim I _4, characterized in that the Charging signal (Us) from an actuator (13) for the charging current (Ia) is tapped, 3, charger according to claim I ₅ . characterized in that the electronic switching element (62) for the charging lamp (6l) is a Sehalttransistor ₃ whose base on the one hand via a resistor (6 * 0 to the positive output (32b) of the charging rectifier (32) and on the other hand via a further resistor 5098 18/0421 -I ₇ - XT. - if (65) a via the switching path of the threshold switch (63) and a Schwellxtfert resistor (66) with the negative output (32c) of the charging rectifier (32) is connected » 4ο charger according to claim 3 _S characterized _s that the threshold value is constructed from two complementary transistors (67 _s 68) (63) is coupled to _a whose first transistor (67) with its switching path to the base of the switching transistor (62) and its driving path the switching path of the second transistor (68) is connected in parallel » 5 «charger according to claim ¹ I ₂ characterized _s that the control path of the first transistor (67) and parallel thereto lying switching Streeke of the second transistor (68) on the one hand via a resistor (69) at the positive output (32b) and on the other hand via the Schwellwertwiderstand ( 66) is connected to the negative output (32c) of the charging rectifier (32) « δ »Charger according to claim 5 _S, characterized _in that ΰ the base of the second transistor (68) is fed the charging signal (Us) to =« 7 ο charger according to claim 6 characterized in that the _{S s} tapped that the load signal (Us) across a resistor (42) _s is arranged parallel to the control path of an actuator serving as _fl in the charging circuit. Transistor ■ (38) switched ^1S1C - SÖ9B 1 8/042 I