How to make the accumulator rectifier for the automobile accumulator
The simplest accumulator rectifier for automobile and motorcycle rechargeable batteries, as a rule, consists of the reducing transformer and the two-half-period rectifier connected to its secondary winding. Consistently with the battery include the powerful rheostat for installation of the necessary charge current. However such design turns out very bulky and excessively power-intensive, and other ways of regulation of the charge current usually significantly complicate it.
In industrial accumulator rectifiers sometimes apply KU202G trinistor to straightening of the charge current and change of its value. Here it is necessary to notice that forward voltage on the included trinistor at the big charge current can reach 1,5 Century. Because of it they strongly heat up, and according to the passport temperature of the body of the trinistor should not exceed +85 °C.
In such devices it is necessary to take measures for restriction and temperature stabilization of the charge current that leads to their further complication and rise in price.
Rather simple accumulator rectifier described below has wide limits of regulation of the charge current - practically from zero to 10 A - and can be used for charging of different starter galvanic batteries on tension of 12 Century.
The simistor regulator with in addition entered by low-power diode Bridge VD1-VD4 and R3 and R5 resistors is the basis for the device (see the scheme).
After connection of the device to network at its plus half-cycle (plus on the wire, upper on the scheme) the C2 condenser via the R3 resistor, the VD1 diode and consistently connected R1 and R2 resistors begins to be charged. At the minus half-cycle of network this condenser is charged via the same R2 and R1 resistors, the VD2 diode and the R5 resistor. In both cases the condenser is charged up to the same tension, only the polarity of charging changes.
As soon as tension on the condenser reaches the threshold of ignition of the neon lamp HL1, it is lit, and the condenser is quickly discharged through the lamp and the control electrode of the simistor of VS1. At the same time the simistor opens. At the end of the half-cycle the simistor is closed. The described process repeats in each half-cycle of network.
It is well-known, for example, that management of the thyristor by means of the short impulse has that shortcoming that at inductive or high-resistance active loading the plate current of the device can not manage to reach value of current of deduction during action of the control impulse. One of measures for elimination of this shortcoming is inclusion parallel to resistor loading.
In the described accumulator rectifier after inclusion of the simistor of VS1 its main current proceeds not only via the primary winding of the T1 transformer, but also via one of resistors - R3 or R5 which depending on polarity of the half-cycle of mains voltage in turn are connected parallel to primary winding of the transformer by VD4 and VD3 diodes respectively.
To the same purpose serves also the powerful R6 resistor which is loading of the VD5, VD6 rectifier. Besides, the R6 resistor creates impulses of the discharge current which prolong battery service life.
The main node of the device is the T1 transformer. It can be made on the basis of the laboratory LATR-2M transformer, having isolated its winding (it will be primary) three layers of the empire cloth and having reeled up the secondary winding consisting of 80 rounds of the isolated copper wire with a section not less than 3 mm ² with branch from the middle. The transformer and the rectifier can be borrowed also from the power source suitable on power. At independent production of the transformer it is possible to use the following calculation procedure - in this case are set by tension on secondary winding of 20 V at current 10 A.
C1 and C2 condensers - MBM or others on tension not less than 400 and 160 V respectively. R1 and R2 resistors - the joint venture 1-1 and SPZ-45 respectively. VD1-VD4 diodes - D226, D226B or KD105B. The neon lamp HL1 - IN-3, IN-ZA; it is desirable to apply the lamp with electrodes, identical on the design and the sizes, - it will provide symmetry of impulses of current via the primary winding of the transformer.
KD202A diodes can be replaced with any of this series and also on D242, D242A or others with average direct tone not less than 5 A. Diod place on the duralumin heat-removing plate with the useful area of the surface of dispersion not less than 120 cm ². Simistor also smaller surface area should strengthen on the heat-removing plate approximately twice. The R6 resistor - PEV-10; it can be replaced with five in parallel the connected MLT-2 resistors with a resistance of 110 Ohms.
The device is assembled in the strong box of insulating material (plywood, textolite, etc.). In its upper wall and in day it is necessary to drill air vents. Placement of parts in the box - any. The R1 resistor (charge current) is mounted on the front panel, attach the small arrow to the handle, and under it - the scale. The chains bearing load current need to be carried out the wire of the MGShV brand with a section of 2,5-3 mm ².
When attuning the device at first set the required limit of the charge current (but no more than 10 And) the R2 resistor. For this purpose via the ampermeter on 10 A connect the galvanic battery to the device exit, strictly observing polarity. The cursor of the R1 resistor is turned to extreme position, upper on the scheme, the R2 resistor - in extreme lower, turn on the device in network. Moving the R2 resistor cursor, establish necessary value of the peak charge current.
Final operation - calibration of the scale of the R1 resistor in amperes on the model ampermeter.
In the course of charging current via the battery changes, decreasing by the end approximately by 20%. Therefore before charging establish initial current of the battery slightly more rated value (approximately for 10%).
The termination of charging is put in order on density of electrolyte or the voltmeter - tension of the switched-off battery has to be within 13,8-14,2 Century.
Instead of the R6 resistor it is possible to install the glow lamp on voltage of 12 V with power about 10 W, having placed it outside of the body. It would show connection of the accumulator rectifier to the rechargeable battery and at the same time lit the workplace.Top