Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Transistor is not switching.

Status
Not open for further replies.
D

deepakdkt

Newbie level 6
Joined
Feb 27, 2012
Messages
12
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,362
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
 
Last edited:

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.
 
DSC_0279.jpg
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....
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top