How Does the 5V Rectifier Circuit Protection Circuit Work With Red and Green LEDs?

sir,

the following circuit(Image File) is used in our Design Lab(EC881) for 5V Rectifier Circuit Protection Circuit

the output also comes to be right

Under normal operation : Green LED is glowing and Red LED not glowing

when output is shorted: Red LED Glowing and green not glowing

 

but i cant understand its working mechanism

i mean how the circuit is working

so please help me for the same

There are two separate parts of this circuit. The OVP shunt and the LED indicators. I assume you are not sure about the LED function from your note.

Think about where there is a potential difference in the circuit. If the OVP circuit has connected the positive output to ground, then there is a potential difference between the +5 input and the positive output, but there is no (significant) difference between the positive output and the negative output.

If the OVP circuit is not active, then there is no significant difference between the +5 input and the positive output. There is a significant difference between the positive output and the negative output.

These potential differences are when illuminates the LEDs.

The resistor values on the LEDs are suspect. A 470K resistor with a 5V potential difference will result in a current flow of 0.01mA which wont produce much (if any) illumination on the LED. A similar issue exists with the 270K resistor on the green led.

Sir,
U r right
The LED are not glowing when subjected to 470k or 270k
But when I place 470k with 10k and external 5V then the green LED glowing with very less illuminity
But I want good efficiency of illumination

So suggest me what values of resistors should I used to make the LED glow properly?????

and also sir I am unable to understand its OVP circuit
So kindly explain me its working mechanism
I mean how the transistors is working here????

Hi Sourav Kumar,


Try changing the value of the resistors from 470k to 470E, 270E to 470 E,

270k to 470E

Thanks Sambath sir,I have understood LED part

Could u explain me the working of transistors in this circuit??

Hi Sourav kumar,

See my attachment, right click over the image ,save it to word doc and view it.

Dont forget to review my rating .

Again a lot of thanks Sambath sir,
How can I review your rating sir???

Hi Sourav kumar,,

Click vote up and enter your score no 1,2,3 etc on the score point where 0 is marked.