The Fuse failue alarm that LED display when the load is low resistors the circuit, fuse blow once. LED1,LED2 show fuse state. Im circuit use a few parts.
How it works
This circuit will show the performance of the equipment,or Check the fuse in the circuit.The circuit is small and the power supply voltage of all kinds.
It display with LED, 2-color in one. Which is cathode common kind,the anode has two separate terminals. If the circuit is functioning properly LED, it shown in green colour.The display is red, when the fuse in the circuit is damaged.The resistor R1 limits the current to flow through the LED is about 2 mA.This is enough to make the LED light.If it lowers the R1 down, the LED lights up.
In the normal operation of the circuit and The fuse is not damaged. The zener diode to prevent the green and red LED lights up simultaneously.Zener diode prevents the LED is green and red lights simultaneously.
The high efficiency LED, when connected in parallel. The red LED uses high-pressure, so that only green LED lights up only. Diodes D3 and D4 will prevent dangerous for the LED. While the half cycle negative voltage of the alternating current voltage.However, if the DC supply voltage.I do not have to use diode protection.
How to build this projects
This projec use a few components so can assemble the circuits in to the universal pcb board in Figure 2 are all components layout of This project.
Which is small PCB.
Figure 2 the components layout.
The components Lists.
LED1,LED2_________________LED as you want.
D1,D3_____________________1N4007__1A 1000V Diode
R1________________________120K 0.5W resistors.