Transistor is not switching.

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deepakdkt

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Hi,
i was working on a circuit in which i got BC177 PNP transistor. getting 3.8 voltage @base of transistor , but still its not switching. Transistor is in working condition.
how much voltage exactly required by the transistor to switch ?
the transistor circuit is followed by the voltage divider circuit.

Thank you,
Deepak
 
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Show your circuit. 0.7V is enough to forward bias base emitter junction. Maybe your voltage divider has high resistances and Ib might be very less. Make Ib = 1 or 2 mA.
 

Sir, I have attached the image of the circuit.. Please go through this.

Thank you.
 

PNP means it requires Negative Supply on the Base Terminal to operate. Giving Positive Supply it will be in off position.
 
What's connected to the open collector? How do you determine "switching"?
 
@FvM
Sir there is a pull down resistor connected to collector which i dint mentioned in the given circuit.
 

The circuit is able to source several mA to the pull-down resistor.
In so far it's "working", I think.
 
the problem is solved.
Thank you all ..
i changed the transistor and checked the circuit , now its working ..
might be the diode within the transistor was weak , so it was not switching.
now i am getting 5v @collector
 

That's great you got it working....
 

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