SU868921A1 - Storage battery charging device - Google Patents

Abstract

In a battery charger of the kind in which pulsating d.c. is supplied to the battery (6) from the rectified output of transformer (1) until a threshold device 15 detects the battery is charged, a bimetallic strip (9, 10) responds to the charging current. If the battery draws high current, say upon initial charging, then resistor 9 heats up strip 10 causing it to break the circuit until the strip cools. The resistor and bimetal strip are chosen so as to allow an average current flow within the capabilities of transformer 1, thus obviating the need for a current limit resistor, and protecting the circuit. Once the battery has charged sufficiently, the bimetallic strip ceases to operate. The device is said to enhance reliability and to permit a smaller and lighter transformer to be used. <IMAGE>

Description

I

The invention relates to converter technology and is intended to charge batteries in use.

BACKGROUND OF THE INVENTION There are known devices for charging batteries from a single-phase alternating-current network containing a matching transformer. a mat, a limiting resistor in the charging circuit and a charging termination relay, controlled by a semiconductor circuit 1.

The disadvantage of such devices is low reliability due to the presence of an electromagnetic-type relay element.

A device for charging a battery in two stages is known, in which the switching of charge modes is provided by a unit responsive to the temperature of the battery charge equipment element {2}.

Also known are devices for charging ac1 T1 "single-phase alternating current batteries containing a matching transformer, a limiting resistor and a parallel connected resistor with a transistor operating in a key mode from a semiconductor threshold voltage control circuit toroidal battery 3. In this device, a contactless charging current switching circuit is used, made on a transistor circuit, which increases the reliability of its operation 3.

A disadvantage of the known device is the large weight and dimensions of the matching transformer and the limiting resistor, which are determined by the power consumed by the battery in the first section of the working

10 characteristics 1, f (t), where I jap. - charging current; t is the charge time. In the initial area of the operating characteristic, the power consumption has a maximum value. As the charge current decreases, the power consumption decreases.

The purpose of the invention is to improve the weight and size characteristics of a device for charging a battery.

The goal is achieved by the fact that the device is equipped with a wire resistor, and the key element is made on a thermo-bimetallic plate with a switch, while the wire resistor is wound on a thermo-bimetallic plate and connected in series with the thyristor of the threshold circuit, the thermo-bimetallic plate is connected in series with a rectifying diode and a disconnecting contact. . FIG. 1 shows the basic electrical circuit of the device for the 3; h yes battery pack batteries; in fig. 2 - charging current flow in the first section of the rand battery; The battery characteristics are a and b, respectively, for the proposed and known devices. go transformer The primary winding according to the pins 2 of the mater 1 is connected to the input and 3, the secondary winding of the matching transformer 1 is connected to the charging circuit of the battery 4 containing successively the plate 5, the thermo-bimetallic resistor 6 connected, on which the wire 7 is wound The snatch contact switches off mechanically with thermal bimetal 8. Parallel 5, and the rectifying diode 7 of the sub switch but disconnecting switch, keys, charge resistor yes 9. To the output pins 10 and 11 of the device A 12 L battery torn battery 4 and a voltage resistor connected to the thyristor control electrode} 3 are connected to the resistor 6 in parallel with the connecting signal in parallel with the resistor 6. The lamp 14 and the wire elements 6, 13 and 14 are connected in parallel with its transformer secondary winding 1. Matched diode 8 is preconfigured for 4 power supply rectifiers of the battery 12 with a stressed current. The resistive divider 5 resistor 6 with NIN, the thyristor 13 and the wire set the threshold control circuit of the battery 4. The NIL on the battery terminals is in a manner. The device is working next cut thermoBIf the flow of charge current to the metal plate 5 in the result of electric heating. As a result of loss, it occurs; This means that it changes its size, bends and opens the disconnecting contact of the switch 7. The time of the switched on and off switch 7 does not open the contact, depending on the magnitude of the charge flowing through the thermo-bimetallic plate 5 The greater the I-type of the charged However, the thermo-metomatic plate 5 softens the contacts of the switch 7 and the device is located in a boosted state. The closure and opening of the switch 7 acts as a result of heating of the cooling of the thermo-bimetallic plate by charge-impulse current and occurs according to the law of latitude modular, and in such a way that a smaller effective current value corresponds to a shorter flow time and corresponds to a longer time of its flow through the thermo-bimetallic plate (Fig. 2). With such a law of commutation of the charge current, the matching transformer 1 operates in a mode that allows changing its average power, as well as dispensing with a limiting resistor and, therefore, reducing its weight and dimensions. At the same time, the reliability of operation of the elements of the device is improved, since the possibility of a continuous flow of current through the elements of the device in the mode of a possible short circuit is eliminated in principle. When decreasing the charging current to a predetermined value, the temperature of the thermo-bimetallic plate 5 becomes insufficient to develop an effort to open the contacts of the switch 7. When the voltage on the battery 4 and, respectively, on the discharge divider 12, the voltage reaches the set value, the thyristor 13 by applying a voltage to the signal lamp 14 and the wire resistor 6. The latter heats the thermo-bimetallic plate 5, as a result of which it opens the contact of the switch 7. Subsequently, the current is charged battery 4 flows through the resistor 9 as long as the voltage at the terminals of the secondary battery 4 does not fall below the threshold. This leads to the disconnection of the thyristor 13, the cooling of the thermo-bimetallic plate 5 and the closing of the contact of the switch 7. The device switches back to the intensive charge mode. During normal operation of the device in the process of charging the battery, the warning lamp 1 does not light up. At the end of the charge, when the thyristor 13 is turned on, the signal lamp lights up again. When the device switches from charging mode to charging mode, the signal lamp turns on and off, respectively. Due to the use of the thermo-bimetallic plate 5, the limiting resistor is eliminated, and an increase in the charge time of the battery in the first section of the operating characteristic 1 f (t) reduces the average power of the electric power consumed by the battery from the network, and this makes it possible to choose an overall the power of the matching transformer according to the average power consumption and reduce its weight and dimensions.

The absence of a limiting resistor and the small weight and size of the matching trassformatrr allows you to improve the weight and dimensions of the device.

Claims (3)

1.Vaylov A.M. et al. Automation of control and maintenance of batteries; M., St. Don, 1975. five 2. The UK patent K 1468403, cl. H 2 H, 1977, 3. US patent W 4031450, cl. 320-23, 1977 „ R eleven Riga.1