Can I replace BJT with AND gate in the following circuit

Thread Starter

vivek20055

Joined Nov 4, 2012
88
Hello,

I have to replace transistor with AND gate in my project. How this can be done?. Can anyone suggest me something about this?.




Thanks & regards,
Vivek Alaparthi
 

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DickCappels

Joined Aug 21, 2008
7,955
What is the function of the transistors?
They appear to be some sort of level sensitive switches that produce pulse width modulation or something similar.

What can you tell us about the circuit?
 

Thread Starter

vivek20055

Joined Nov 4, 2012
88
Hello DickCappels,


Thank you for your reply,

This circuit is a external synchronous self oscillator ZVS converter.
As long as voltage at point Vg1 don't go below V1 * R5/(R5+R8) = 2.44V the MOSFET will be OFF. So we can force this by switching ON the BJT or circuit can do it
"himself" via D3 or D2 if the BJT is OFF.

How you suggest me, how to replace the BJT with a AND gate.

Thanks & regards,
Vivek Alaparthi
 

Thread Starter

vivek20055

Joined Nov 4, 2012
88
Hello,

I have been thinking of the connection to the gate drive and the possibility of shutting the device off.
Instead of the BJT used now I tried to remove the two NPN transistors and use a AND gate (74V2T08) for the inputs. The and gate and the resistor after the diode should then both be connected to 5V instead of 12V.



Thanks & regards,
Vivek Alaparthi
 
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