Breadboard power supply. The wide prong of an AC line plug goes to the bottom of the primary of a transformer. The other prong goes through a 0.5 amp fuse then through a single pole single throw switch to the top of the primary. There is a lamp of unspecified type connected in parallel with the primary. The center tap of the secondary is grounded. The top and bottom of the secondary go to the AC inputs, anode and cathode, of a bridge rectifier. The positive output of the bridge, cathodes, goes to the positive side of a 2000 microfarad capacitor. The negative side is grounded. The negative output of the bridge, anodes, goes to the negative side of another 2000 microfarad capacitor. The positive side of this capacitor is grounded. The positive output of the bridge also goes to the input of an LM317 voltage regulator. There is a 0.1 mike cap from the input to ground. The adjust, A terminal of the regulator goes through a 10 mike cap to ground. The A terminal also goes to one end of a 1 k ohm pot connected as a rheostat. The other end of the rheostat is grounded. The output terminal of the regulator goes through an 82 ohm resistor to the A terminal. The output terminal goes through a 20 mike cap to ground. The output terminal also goes to the cathode of a diode. The anode is grounded. The output terminal also goes to a connection point labeled positive 1.2 to 15 volts. The positive output of the bridge also goes to the input of an LM309K 5 volt regulator. The common terminal of the regulator is grounded and the output terminal goes to a point labeled positive 5 volts. There is a 0.1 mike cap from input to ground and another one from output to ground. There is a 100 mike cap from the output to ground. The negative output of the bridge goes to the input of an LM337 negative adjustable voltage regulator. There is a 0.1 mike cap from the input to ground. The adjust, A, terminal goes through a 10 mike cap to ground. The A terminal also goes to one end of a 1 k ohm pot connected as a rheostat. The other end of the rheostat is grounded. The output of the regulator goes through an 82 ohm resistor to the A terminal. There is a 20 mike cap from the output to ground. The output also goes to the anode of a diode. The cathode is grounded. The output goes to a point labeled negative 1.2 to 15 volts. End verbal description.
Go back.