Schematic diagram of a simple symmetric regulated power supply is shown in Figure 1.
The power supply is a standard application LM317 ICs (control positive voltage) and LM337 (negative voltage regulator), in which all the elements of a high-end voltage regulator housed in buildings. Stabilizers requires only a few external components to work properly, and their primary use has been extended through the bridge rectifier and capacitors, filtering the input voltage. Chip LM317 and LM337 are protected, prevents its overheating or damage, cause a short circuit at the output. Light-emitting diodes LED1 and LED2 indicate the presence of voltage at the output of the power supply. The output voltage is determined by means of potentiometers PR1 and PR2 in the range 1,2 … 24 DC. It is recommended to use a transformer, with the voltage on the secondary 2 × 17 AT. Driving power source assembly shown in Figure 2, and the method of its connection to the transformer – on the image 3.
In a sample of all that has been collected on the double-sided printing plate size 33 mm × 62 mm. Power Supply, collected from the working components, does not require any setup operations, and after the input voltage connection it is immediately ready for. Chips U1 and U2 when working with a relatively low load current – order 300 mA makes no sense to put on the radiators. While the maximum current stabilizers are much higher.