[SOLVED] Need Testing Circuit for opto coupler A 4504 or HPCL4504

[anandprem2]

Hi Frnds,
pls help me, i had a motor drive circuit with FET k1516, which fet are shorted. fet is driven by opto coupler A4504. I need to check wheter is ok or not. if i place faulty means, again fet wil be shorted,
i would appreciate if u guide me..
Thank u

 

[mtwieg]

Do you want to test the optocoupler or the FET? And is this an in-circuit detection, or do you want to check components on the bench?

 

[anandprem2]

Do you want to test the optocoupler or the FET? And is this an in-circuit detection, or do you want to check components on the bench?

Thank u for reply.. Bt I need to check optocoupler only.. Becoz fet has been short and burnt..
I taken out opto coupler from pcb. So I need out circuit test.
Thank u..

 

[mtwieg]

The datasheet for the HCPL4504 gives a couple schematics for test circuits, for example figure 6.

 

[anandprem2]

any other simple testin circuits, coz i dont have sig genrators.
sorry and thank u..

 

[mtwieg]

any other simple testin circuits, coz i dont have sig genrators.
sorry and thank u..

If you just want to test whether the output toggles correctly, you can just use the same circuit but replace the function generator with a switch that connects the LED to either a positive supply voltage or ground through an appropriate current limiting resistor. Though this won't be able to really tell you about the switching speed or delay of the device.

 

[anandprem2]

Yes i tried as u said. i connect 5v i/p through 1k reistor. and connect another 1K resistor from vcc to o/p. wen i/p is given, the o/p drops to gnd.
wen i/p is off, o/p is equal to vcc. so device is in workin state. i need this only.
thank u for ur help.