DE8700100U1 - Device for charging several batteries simultaneously - Google Patents

Description

Müller · * ·"::":. !·-! .·' 6086

* · f Ct *

DESCRIPTION

Device for charging multiple batteries simultaneously

The invention relates to a device for simultaneously charging several batteries, in which a power supply unit and a charging unit are arranged for each battery.

A device of this type is known, for example, from DE-PS 33 41 191. There are several charging units assigned to the various batteries to be charged. The known device essentially concerns protection against reverse polarity, which is achieved by a third connection-output contact element. As far as charging several batteries is concerned, this device has the disadvantage, among other things, that the operating voltage is looped through the individual charging units. As a result, the number of charging units that can be connected is limited by the performance of the first charging unit arranged after the transformer unit.

The invention is based on the object of designing a device of the type described in more detail above in such a way that the individual charging parts are independent of one another and charging can be carried out in a way that is adapted to the charge state or the quality of the various batteries.

This object is achieved according to the invention in that a bus board fed by the power supply is arranged in a housing, to which charging parts designed as automatic charging/discharging units are connected in parallel, and that switchable measuring units for power and voltage are provided for all batteries via the bus board via the charging parts.

According to a further development of the invention, it is provided that the bus board is connected to a power supply for non-mains-connected operation.

Another embodiment of the invention consists in that the bus board is assigned a power supply unit for supplying external consumers.

A special embodiment of the invention is that an adapter attachment is arranged on the housing to accommodate the batteries to be charged, via which the batteries are connected to the charging parts.

According to the invention, it can also be provided that the charging parts have means for defined discharging up to the final discharge voltage as well as means for voltage and time charging of the batteries and for applying a trickle charge current.

It is also within the scope of the invention if the charging parts have voltage window generators and a reference voltage window generator assigned to the measuring units in such a way that only one charging part is connected to the measuring unit via the bus board.

6086

The advantages achieved by the invention are

in particular that the number of loading parts exclusively on the capacity of the transformer part and is connected to all charging parts as well as to each charging unit individually, depending on the charging state and quality of various batteries and can be charged automatically.

An example of implementation is shown in the drawings and is explained below.

the basic arrangement according to the invention, schematically the spatial arrangement of the essential elements of the charging device, the new device with an adapter attachment, the front panel and

the block diagram of a charging unit, the front panel of a voltage measuring unit and Fig. 7 that of a power measuring unit.

In Fig. 1, 1 denotes a power supply unit, which on the one hand is connected, for example, to the general (220V) power supply and on the other hand supplies a direct current of the required magnitude to the bus board 2. The power supply to all charging parts 3, 4 to η is via the bus board 2, to which the charging parts are connected in parallel. As a result, each charging part 3, 4 to η draws the required current directly from the power supply unit 1, with the bus board 2 being connected in between.

The measuring units 5 and 6 provided for the voltage and power of the batteries 7, 8 to &khgr; to be charged are also connected to the power supply unit 1 via the bus board 2, as is any power supply unit 9 that may be present for supplying external consumers (Fig. 2,

In the case of mobile use of the device according to the invention, it is expedient to use a power supply unit 10

i|, which can be used, for example, by a car or

*?; truck battery can be supplied (Fig. 2, 3).

The bus board 2, which functions as a cable system, i: also has the task of establishing the connections to and from the

I charging units 3, 4 to &eegr; and the measuring units 5 and

§ 6 to establish a voltage and power measurement

■f of the batteries to be charged.

■ Fig. 2 shows schematically the arrangement in a housing

11 of the charging parts 3, 4 to n, to which the batteries (not shown here) are connected via connections 12, 13 to y. The bus board 2 is connected to the power supply 1 and provides the connections to

:. ) units 3, 4 to n, 5 and 6 and 9 and 10,

and also the connections between the units.

£ Instead of arranging the batteries in front of the housing 11,

According to the invention, an adapter attachment 14 for the housing 11 is provided, which accommodates the batteries 7, 8 to

:.. «c, as shown in principle in Fig. 3.

) In this case, the batteries 7, 8 to &khgr; are charged via the

Ij desk 15 connected to the charging parts 3, 4 to &eegr;,

&psgr;: which in turn has a detachable connection 16

is electrically coupled to the charging parts 3, 4 to &eegr;. This creates a spatially manageable, space-saving unit consisting of the charger and the batteries to be charged.

The essential elements of the new device are the charging parts 3, 4 to η, each of which is designed as an automatically operating charging/discharging unit. The latter means that on the one hand a time charge with preceding discharge up to the final discharge voltage and on the other hand a voltage charge is provided.

Time charging is used for batteries from which a large part of their charge has been removed and which do not need to be recharged in a very short time. Batteries from which only a fraction of their charge has been removed can be charged directly to the final charging voltage using voltage charging. The charging parts 3, 4 to η have a switch 17 (Fig. 4) for selecting the positions "voltage charging" or "time charging".

Using Fig. 4 and 5, the latter represents the block diagram of the charging parts 3, 4 to n designed as a charging/discharging unit, the operation of "time charging" is first described: The switch 17 is set to "time charging". Now a battery 7, 8 or n is inserted into the socket 12, 13 or y provided for it in a charging unit 3, 4 or n or into a compartment of the adapter attachment 14 and then the "Reset" button 18 is pressed. A first comparator 19 is thus released and compares the terminal voltage of the battery 7, 8 ...n with a set reference voltage which is equal to the final discharge voltage.

of the battery. If the output of the first !Comparator

19 "Low", a flip-flop is connected

20, which via a transistor the charging relay

21 and thus the switching regulator 22, which is now operated as a discharge stage, to discharge the battery 7, 8 ...n are used. When the charging relay 21 switches over, a second comparator 23 is automatically released, which in turn compares the falling battery voltage with the reference voltage described at the beginning. Only when this voltage is reached does the output of the second comparator 23 become positive and sets a counter 24 in motion.

If the counter 24 is set, its output goes to "Low" during the time set on the main charging current/charging time switch 25, thus enabling the switching regulator 22, which receives the positive supply voltage and supplies the charging current.

The charging current is set in two ways. The battery nominal current is normally fixed. It is set using a voltage divider 26. The output of the voltage divider is fed to a fourth comparator 27. The main charging current/charging time switch 25 is then used to switch the gain of an amplifier 28, which measures the voltage drop across a measuring resistor 25, through which the charging or discharging current flows, and switches this voltage drop to the second input of the fourth comparator 27. The fourth comparator 27 controls the switching regulator 22 with its output and thus regulates the charging current.

When the battery 7, 8 ...&eegr; has reached its final charging voltage, the output of the third comparator 30 becomes positive and switches the main charging current to trickle charging current with the help of a transistor. A display circuit 31 controls two LEDs 32 and 33 (Fig. 4), which signal that the battery is being charged or that it is full. The LED 34, which indicates that the battery is being discharged, is connected in parallel to the charging relay 21. All three displays are "effective displays", i.e. they only light up when the battery is OK. For example, if the connection cable of the

If the batteries were defective, none of the LEDs would light up.

The other option, "voltage charging" with the same charging unit, is carried out in the manner described below.

The main current/charging time switch 25 is set to the desired time (or the associated charging current) using the switch. Now you only have to set the changeover switch 17 to "voltage charging". The battery is now charged with the previously set charging current until it is normally switched off by the third comparator 30 or switched to

Maintenance charge current. When switch 17 is switched from "time charge" to "voltage charge", the counter described above is started at the same time and switches the charge current to maintenance charge current at the latest after the set time has elapsed.

A special measuring unit 5 makes it possible to track the voltage curve during charging or discharging of the batteries. To do this, set the switch

35 to the charging unit 3, 4 ...n or the battery 7, 8 ...x to be measured. On the digital display

36 you can now read the battery voltage value (Fig. 6).

';■' For example, to charge a newly inserted battery that you do not know

&xgr; knows what its charge level is, switches

f , , you first load the corresponding main ro i-/

Charge timer 25 to max. discharge current and press

then the "Reset" button on the same charging unit. When the battery is empty, the charging circuit jumps from discharging

I directly to charging. However, if the battery still has enough

£ capacity, the digital display 36 shows its current

I' Voltage, whereby a discharge current (of 4x I nominal)

I flows. It is also possible to use a battery,

e which is still being loaded, to determine how its current

state of charge. This is often the case in current reporting

§ very important for radio or television, as you can

) Battery then also shortly before its charging current shutdown

If you have several batteries with an undefined ■ charge level, this measuring method is also useful,

' to separate the empty from the full batteries.

Another measuring unit 6 is intended to measure the performance (quality) of batteries.

• For this it is necessary that the battery is fully charged.

&igr; Now set switch 37 (rig. 7) to the

I selected battery 7, 8 ...x. By pressing the

By pressing the "Resef" button 18, the battery is discharged with the current previously set on the main charging current/charging time switch 25. Normally, the "C" position is selected for this, as it corresponds to the nominal current of the battery. The discharge time for a new battery should be 10 hours. In this case, the digital display 38 of the measuring unit 6 would show "100 X" .

While the battery is being discharged, a counter runs that emits a pulse every 6 minutes. These pulses

/ are processed by a decimal counter with seven-segment decoder

and driver are processed and displayed. Since the pulse sequence is 6 minutes, the display is calibrated in percent. (10 h = 600 min. = 100 x 6 min).

When the battery has reached its final discharge voltage, the charging unit 3/ 4 ...n automatically switches back to charging.

It is possible, for example, to start this measuring process in the evening in order to read the display the next morning and find that the battery is fully charged again.

<' To further test the performance,

the main charging current/charging time switch 25 is first set to position "B" (2x I nominal). Now the display should show "50 X" after the discharge time has elapsed, since the battery was discharged with twice the nominal current. "25 X" should be readable in position "A" since the battery is now discharging with α times the nominal current.

The older a battery gets, the more its internal resistance increases. Since this is less important with a low discharge current than with a

comparably higher, this measuring method is ideal for determining the quality (service life) of a battery. As previously described, the values should normally be either 100 % in position "C", 50% (100 % eff.) in position "B" or 25 % (100 '/. eff.) in position "A".

For example, a battery can display 99% in position "C", 46 % (92% eii.) in position "B" and 20% ( 50% eff.) in position "A". This indicates that the internal resistance is too high. An internal resistance that is too high results in the following measured values: position "C" 90%, position "B" 50% (80% eff.) and/or position "A" 15% (60% eff.). These measured values can be used to measure the current performance of a battery and to roughly estimate the expected service life.

This makes it possible to use batteries in a more targeted manner than before. For example, a battery with poor values can mainly be used for devices that consume little power, while the better batteries can be used for devices with higher power requirements. This means that the "consumption" of batteries can be reduced or optimized, and thus the number of charging processes is reduced, which, among other things, saves a considerable amount of time.

Each measuring unit 5, 6 has an 11-stage voltage divider. One of the 11 outputs is forwarded by switch 35 or 37 to the bus board 2, which connects all units to one another.

Each charging part 3, 4 ...n contains two voltage window generators 39 and 40 (Fig. 5) coupled to a reference voltage window generator 41, which only provide an output signal at a specific voltage. The voltage window generator 40 receives its control signal from the voltage divider of the measuring unit 5 for the voltage measurement, the other window generator 39 from the voltage divider of the power measuring unit 6. Each charging part 3, 4 ...n has, for example, a series of jumpers with which it can be programmed to a specific voltage. This ensures that during a voltage or power measurement only one charging part 3, 4 ...n forwards an output signal to the bus board 2, which is then evaluated and displayed by the corresponding measuring units 5, 6.

Claims (6)

R. Müller &iacgr; · '· · : : · · :"· :' 6086 PROTECTION CLAIMS 1. Device for simultaneously charging several batteries, in which a power supply and a charging unit for each battery are arranged, characterized in that in a &zgr;"I housing (11) a from the power supply (1) fed Bus board (2) is arranged, to which charging parts (3, 4 ...n) designed as automatic charging/discharging units are connected in parallel and that all batteries (7, 8 ...x) are charged via the bus board (2) via difc (.divide (3, 4 n) switchable measuring units (5, 6) for the power and voltage provided. 2. Device according to claim 1, characterized in that the bus board (2) is connected to a power supply unit (10) for off-grid operation < ' is connected. 3. Device according to claim 1, characterized in that the bus board (2) is assigned a power supply unit (9) for supplying external consumers. 4. Device according to claim 1, characterized in that an adapter attachment (14) is arranged on the housing (11) which receives the batteries (7, 8...x) to be charged and via which the batteries (7, 8...x) are connected to the charging parts (3, 4...n). 5. Device according to claim 1, characterized in that the charging parts (3, 4 ... n) have means for defined discharging up to the final discharge voltage >ouie means f , ~\ to the voltage^- and time charge of the batteries (7, 8 ...x) and to provide a trickle charge current. 6. Device according to claim 1, characterized in that the charging parts (3, 4 ... n) of the measuring units ft (5 , 6)in the manner assigned voltage window Generators (39, 40) and a reference voltage Window generator (41) such that only one charging part (3, 4 ... n) is connected to a measuring unit (5, 6) via the bus board (2).