Adjustable bipolar power source 12/6 volt 2 ampere
In the laboratory of radio Amateurs usually have adjustable stabilized power supply. Adding a simple console, you can obtain a bipolar power source.
The scheme of such a console is shown in the figure. It is designed to work in conjunction with the stabilizer, having an output voltage of 12 volts and the load current is 2 A. the Attachment is equipped with a power amplifier transistors, which increased the efficiency of the device when the load resistance changes in a wide range.
The ratio of output voltages of the source can be changed within...1,6 0,6 variable resistor R2. When the ratio is equal to 1, the maximum load current of each arm is equal to 2 And, at the same values should be reduced in 1,5...2 times. Console works like a voltage regulator in parallel with regulating element.
Operational amplifier A1 compares the output voltage of the resistive divider R1R2R3 voltage at the output of "GENERAL." power amplifier V5, V6. The difference between these voltages is minimized by an appropriate change of the bias voltage of the transistor V3. Chain V1V2R4 is used for the initial setting of the offset voltage of this transistor. If you want to increase output voltage shoulders consoles with 6 to 12, the tension of her power to raise up to 24 In and replace operazioni on QUTB. This will require a corresponding change (increase) the resistors R4 and R5.