This circuit motivation let somebody see the performance of the equipment,otherwise Check the fuse arrived the circuit.The circuit is insignificant and the power supply voltage of all kinds. It parade with LED, 2-color in single. Which is cathode normal kind,the anode has two separate terminals. If the circuit is functioning accurately LED, it exposed in environmentally friendly colour.
The display is red, at what time the fuse voguish the circuit is damaged.The resistor R1 limits the current to stream through the LED is going on for 2 mA.This is a sufficient amount to do the LED light.If it lowers the R1 down, the LED light up. In the regular action of the circuit and The fuse is not damaged. The zener diode to prevent the green and red LED light up at once.Zener diode prevents the LED is sea green and red illumination at the same time. The high-pitched efficiency LED, whilst connected in the sphere of congruence. The red LED uses high-pressure, so with the intention of single green LED illumination up only. Diodes D3 and D4 command prevent perilous in support of the LED. While the semi cycle denial voltage of the alternating current voltage.However, if the DC supply voltage.I perform not include to application diode protection.