[SOLVED] LED indicator for Load Connected

[vijay s]

sensing led indicator

hai
i need a guidance on how to make an LED Glow only when the Load is connected..
i have an application in which Power Supply outputs an 5v.when the Load is connected to this Power supply an LED has to Glow indicating load is connected and LED should Turned OFF when Load is removed

anybody have any idea on this...

i need quick help.. it's very urgent

 

[hakeen]

voltage drop led indicator

How much is the max allowed current from your power supply's output?

 

[mfarooq1]

comparator led indicator

Hi
If your power supply is switch mode then it must have a current sensing resistor and you have to detect voltage across this current sensing resistor with any opamp or comparator. you need to adjust the threshold for load. mean on what load current the led will glow this can be done with adjusting the reference of comparator.
If your supply is not switch mode then you can add a current sensing resistor.
by the way most of regulated power supply current sensing resistor must should be there.

 

[vijay s]

lm385 sensing resistor

How much is the max allowed current from your power supply's output?

2 Amps and 5v
and i'm using LM2596 regulator from National Semiconductor

Added after 2 minutes:

Hi
If your power supply is switch mode then it must have a current sensing resistor and you have to detect voltage across this current sensing resistor with any opamp or comparator. you need to adjust the threshold for load. mean on what load current the led will glow this can be done with adjusting the reference of comparator.
If your supply is not switch mode then you can add a current sensing resistor.
by the way most of regulated power supply current sensing resistor must should be there.

could you explain me with using Current Sensing Resistor

 

[mfarooq1]

led indicator for opamps

Current sensing resistors are connected in series with load. they are high wattage and low resistance i.e 0.1 ohms or less then 0.5 ohms.
I have seen the ic u r using is a switching regulator.
first you have to check voltage across the inductor connected on its output with connecting load or disconnecting load from the supply.
if it gives voltage even in milivolts then it is enough for you to get amplified with opamp.
if it not then connect a of (0.1 to 0.5) ohms in series to load and check the voltage across that resistor.
use opamp or comparator to get your desired function.
I am Uploading the IC datasheet.

Added after 1 minutes:

LM2596 Datasheet

 

[vijay s]

thank you guys for replying ...

i finished that successfully.. as u guys mentioned i used current sensing resistor and LM385 op-amp as comparator to compare the Voltage drop across current sensing resistor .. just it works