The device provides charging current up to 6A, the control current and voltage with a dial gauge, short-circuit protection and automatic shutdown after a specified time using the timer. The scheme consists of a sawtooth generator transistors VT1, VT2, comparator DA1, signal amplifier with shunt current detecting an operational amplifier DA2 and output power thyristors VD5, VD6, which are mounted on small radiators, in which we can use a metal enclosure.Setting up the scheme in several steps: 1. Oscilloscope measured amplitude "blade" on variable resistor R6, which should be about 2V, otherwise its selection of the resistor R4 is adjusted to this value.Next load current shunt R18 6A and the selection of resistors R15, R17 achieve the level of the input voltage of the comparator 3, equal to the amplitude of the sawtooth 2B -then the charger starts normally regulate the output current.2.To exit device series with the external model ammeter connected rechargeable battery, the current regulator is set to 3 ... 6 A, and toggle the charger switches to the "current". Selection of resistor R14 achieve correct current readings on a scale built-in appliances.3. Battery connected directly to the output of the charger and monitor the voltage on it with an external voltmeter model. Selection of resistor R20 achieve correct readings built galvanometer scale voltages.The configuration is complete. The measuring device may use any available head, wherein a linear scale is necessary to prepare in advance. Shunt R18 can be made from a length of nichrome wire with a diameter of about 2 mm and a length of about a 15 cm Accuracy of resistance is largely irrelevant, since the selection of resistors R15, R17 to set the required value of the signal at the output of DA2. When you run a safe enough thyristors capacitor C6 may be removed and replaced by a resistor R11-watt, 510 ohm nominal value ... 1k. Timer does not require a separate setting, if desired it can not produce -the rest of the circuit will not change. Basic electronic elements are assembled on a printed circuit board.
This scheme has passed the test of time, does not contain deficient or less common elements, but during this period there was a new element base available, allowing you to build a power supply with higher performance.Diagrams shown on the following pages section developed relatively recently, using currently available elements and suitable for repetition hams average.