hai how it works it is intresting

[grittinjames]

hai this is a application circuit i am not getting how this transistor getting off


plz tell me

 

[Eugen_E]

It is well explained in the application note, with details and scope image.

 

[grittinjames]

hello bai ,look it properly once

base voltage given to transister is suffecient to turn on it , even though it is not in saturation, once it become on due to +ve feedback winding it will take to saturation.when core become saturate ur feed back winding vtg also become 0, but still to make transister fully off some -ve vtg is required to apply to base , how this vtg will induce to feedback winding

 

[A.Anand Srinivasan]

when the inductor W1 saturates it means that all the energy is stored in the form of magnetic energy and this means no current or very less current which is not enough to drive the transistor and hence the transistor turns off...

 

[grittinjames]

thanks for respond Mr Anand

but initialy tranistor turned on with the help of this same voltage

that means base vtge applied is good enogh to make transistor on , other wise oscillation will not start at all,


then i am coming to ur conclusion

as per u transistor turn off due to less current , then how it turn on for next cycle ?

ha ha

realy funny

 

[A.Anand Srinivasan]

when the transistor turns off the other inductor W2 magnetic field collapses which makes W1 magnetic field collapsing which results in current drive to the transistor which then turns it on and after sometime saturation occurs and transistor turns off... this continues....

 

[grittinjames]

i think ur explanation is not right ,

there is some negative voltage shuld induce in feedback winding to turn off trasister fully

how it will generate

 

[A.Anand Srinivasan]

dude the inductor is a reactive component and once it starts saturating the current through it starts dropping... for a inductor V=L(di/dt) and hence when the current starts reducing di/dt becomes negative and the voltage across the inductor starts becoming negative.... so the transistor turns off...

hope it is useful....

 

[grittinjames]

bai once inducter get saturate current is not getting drop it will be maximum as per my knowledge

but due to no change in current induction will happen to cuppled inducter

 

[petergay38]

Dear Sir, Can somebody help with a Class D high
power Circuit Digram About 1000 Watts into 8 omhs
as I like to build one to use in my Band,I really cant
afford to buy one. Thanking You.
Peter Gay.
my Email address.peter.gay@gmail.com

 

[grittinjames]

ur realy a new bie
create a new topic and post this

 

[A.Anand Srinivasan]

dude when W2 saturates there is no feedback to W1 since the current in W2 is constant and hence the current through W1 starts dropping and this would lead to a negative voltage....