PL113320B1 - Automatic storage cell charging system - Google Patents

Description

The present invention relates to an automatic battery charging system, the charging current of which depends on the degree of charging of the battery.

There is known a DC power supply with an output current regulation that enables the charging of batteries, having a thyristor connected anode to the input of the power supply and a cathode to the positive pole of its output. The signal that extinguishes the thyristor in the final phase of each half of the supply voltage is fed from the control system to the thyristor gate. The power supply is equipped with an additional thyristor protection system against overload or short-circuit at the output, a controlled difference of the output voltage and constant voltage, supplied from a separate power source.

This power supply is very complex, and also has the disadvantage that it is damaged when the battery terminals are connected in reverse.

The object of the invention is to construct a simple system for automatic charging of batteries limiting the battery charging current to an acceptable value, irrespective of the degree of charge, and interrupting charging when the battery is charged, as well as insensitive to overloads, short circuits and improper battery connection.

According to the invention, this object has been achieved by constructing a circuit in which the thyristor has a cathode connected to the input rectifier, and the anode to an output terminal connected to the negative battery terminal. The gate of the thyristor is connected via a trip circuit consisting of a transistor and a resistor shaded by an illuminating element, preferably a light bulb, with an output terminal connected to the positive terminal of the battery. The base of the trip transistor is connected to the output of the battery voltage comparison circuit, divided by a divider, with the voltage of the reference voltage source.

The system ensures precise charging of the battery to a specific voltage, and maintaining the charging state at this state by cyclically closing and opening the charging circuit. When the battery is disconnected, the short-circuit currents no longer flow through when the circuit's charging terminals are closed, since the charging path is closed. Incorrect connection of the accumulator does not open the landing path and currents damaging the system do not open up. Only the correct connection of the battery opens the way of charging and such a state is indicated by the lighting element.

The subject of the invention is explained in more detail on an example of embodiment in the drawing, which shows a schematic diagram of the system.

At the input of the system there is a transformer 1, the primary winding of which is connected through a fuse 2 to the network. The secondary, split winding 113 3203 of transformer 1 is connected through a rectifier in a two-pole circuit, comprising two diodes 3 and 4, with a resistor 5, the other end of which is connected to the cathode of thyristor 6. The thyristor anode 6 is connected to the output terminal of the circuit. designed to connect the negative pole of the battery, while the thyristor 6 is connected, through a series of resistor 7, bypassed bulb 8, and the collector-emitter junction of the transistor 9, with the output terminal connected to the secondary winding of the transformer 1, connected to the positive pole of the battery. The base of the transistor 9 is connected via a resistor 10 to the output terminal for connecting the positive battery terminal and via a resistor 11 to the emitter of the pnp transistor 12, the collector of which is connected to the base of the npn transistor 13 and to the output voltage divider consisting of of resistors 14 and 15. The collector of transistor 13 is connected to the base of transistor 12 and the emitter to a second voltage divider consisting of a zener diode 16 connected to the output terminal for connection to the positive terminal of the battery and a resistor 17 connected to the opposite terminal output. The transistors 9, 12 and 13 together with the resistors 7, 10 and 11 and the light bulb 8 constitute the trip circuit 18.

The operation of the system is as follows. Thyristor 6, located in the circuit's current path, is controlled by a signal from the control circuit, including transistor 9, and the comparison circuit, including transistors 12 and 13, depending on the magnitude of the rfa voltage from the battery connected to the system output terminals.

In the event that the battery connected to the output terminals is discharged, the difference between the voltage at the Zener diode 16 and the voltage at the divider's divider point r ^ / 4, compared by transistors 12 and 13, exceeds the specified a limit value that causes the current to flow through transistors 12 and 13, and thus to provide a signal to the base of transistor 9. Transistor 9 is saturated and the voltage signal from its collector is fed through the circuit of the bulb 8 and the resistor 7, on thyristor gate 6.

The current flowing under the influence of this signal causes the thyristor to enter the conduction state, and thus to open the charging circuit. The thyristor 6 is open until, as a result of charging the battery, the voltage difference between the voltage across the ze-3 320 4 diode 16 and the voltage across the resistive divider 3,4 becomes a value lower than the limit. The transistors 12, 13 and 9 become clogged, which interrupts the flow of current in the gate circuit 5 of transistor 6, thereby blocking the thyristor and interrupting the flow of current in the landing circuit.

In the event that the voltage at the terminals of the battery connected to the charger drops due to leakage or other losses, the thyristor. it will reopen and the charge cycle will repeat. This keeps the battery at full charge all the time.

In the event of a disconnection of the battery, no voltage is present at the output terminals of the charging circuit, which is very advantageous because of the possibility of accidentally short-circuiting the output of the circuit, operated by users with a very different level of technical knowledge. 20 Reverse connection of the battery to the system does not cause the flow of current, and therefore has no negative effect on the operation of the system. PATENT LIABILITY AS TARRET 1. A system for the automatic charging of batteries, comprising an input AC constant voltage converter and a thyristor in a series circuit, characterized in that the thyristor (6) has. cathode connected to the input converter, anode connected to the output terminal connected to the negative terminal of the battery, and a gate with a trigger circuit (18), controlled voltage difference of the reference voltage source, most preferably a Zener diode (16) and an output divider wego <14, 15). 2. System according to claim The method of claim 1, characterized in that the trip circuit (18) comprises a transistor (9) which. The 40th collector is connected to the thyristor gate (6), the emitter is connected to the output terminal x connected to the positive battery terminal, and the base is connected to the output of the voltage reference circuit fed 45 from the battery (16) and the resistive divider ( 14, 15), the comparison circuit comprising preferably two transistors (12 and 13) connected in a mutual amplification circuit. 3. System according to claim A method according to claim 2, characterized in that the transistor (9) has a cathode connected to the gate of the thyristor (6) through a resistor (7), shunted by a light element, preferably a light bulb (18).