Power Circuit Board Write-Up

Power Circuit

Parts List

• D1 1N4001 1000v silicon diode
• D2 1N4001 100v silicon diode
• Zener diode
• Capacitor electrolyte radial 25V 33uF x2
• Voltage regulator LM317T
• R1 resistor 1k
• R2 resistor 330R
• R3 resistor 100R
• LED 2.02v 30mA 5mm
• Jumper Wires x3
• Red lead 12volt outputpower supply
• Yellow lead 5volts output power supply
• Black lead Earth wire

Calculation for resistors used in the Power Circuit

R1 = 1k +/- 5% 0.5 watts

R2 = 330R +/- 5% 0.5watts

R3 = 100R = +/- 5% 0.5watts

Test Procedure

To make this power circuit working you need to have 12v power supply. This is connected to red lead (positve) and black lead (negative) of the power circuit, therefore when the 12v is linked then the Red LED should light up but not only Light up it should be able to get 5v output from the power circuit when the 12v is supplied.

How the circuit works

Inorder to get this circuit working 12volts power supply is needed. The first diode is in the 12volts positive rail which is in forward bias of 0.7v dropping the voltage to 11.3volts. The zener diode is also connected in the reversed biased direction passing through the capacitor which does not make any difference in regulating the voltage and links up with the voltage regulator. The adjust pin from the voltage regulator attaches to 1k resistor then to earth. 330R resistor is then connected from the 1k resistor to the output of voltage regulator. The capacitor 2 is now attached in the output rail from voltage regulator therefore the jumper lead is connecting from the output rail to the second diode which makes the circulation of power in the voltage regulator. Finally 100R resistors is now linked from the output rail to the LED to earth. This completes my circuit and it works leaving the three lead wires of 12v output, 5v output and grounding.

Fault Findings

In this circuit I did not have any faults because my circuit worked at the first attempt. Inorder to find the fault its must to check for volt across the components and to ensure that they are in good working condition.