Monostable multivibrator no input, the transistor1 in active mode?

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Discussion Overview

The discussion revolves around the behavior of a monostable multivibrator circuit, specifically focusing on the state of transistor T1 when there is no input signal. Participants explore whether T1 can remain in active mode continuously and the implications for current flow in the circuit.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • Some participants question whether T1 being in active mode all the time allows for current flow in the circuit, with one expressing skepticism about the possibility of current flow.
  • Others suggest that if T1 is on, the circuit will remain stable until a negative input pulse is applied, which would charge the input capacitor and turn T1 off, but this can only occur once.
  • There are repeated assertions that if T1 is in the active region, current will flow through resistors RC1 and R, provided that the circuit is connected to a suitable voltage rail.
  • One participant raises a question about how current would move if the circuit is powered only by DC and contains capacitors, emphasizing the need for a negative pulse to initiate current flow.
  • A later reply suggests that the discussion resembles a homework exercise and points to external resources for understanding the operation of a standard monostable multivibrator circuit.

Areas of Agreement / Disagreement

Participants express differing views on the implications of T1 being in active mode continuously, with some asserting that current will flow while others question this assumption. The discussion remains unresolved regarding the exact behavior of the circuit under the specified conditions.

Contextual Notes

Participants have not fully resolved the implications of the circuit's configuration, particularly regarding the role of capacitors and the necessity of input pulses for current flow.

Outrageous
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If T1 is in active mode all the time, will there be any current flow in this circuit? ( I think it is impossible to flow) thanks
 

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If T1 is on then the circuit will remain stable until... The input on the bottom left has a capacitor in series with a diode. The first negative input pulse will charge the input capacitor and flip T1 to off, but that can happen only once.
 
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Outrageous said:
If T1 is in active mode all the time, will there be any current flow in this circuit? ( I think it is impossible to flow) thanks
If T1 is in the active region, there will be current flowing✻ in RC1 and R at least.

✻ assuming the lower horizontal line is connected to a suitable voltage rail[/size]
 
NascentOxygen said:
If T1 is in the active region, there will be current flowing✻ in RC1 and R at least.

✻ assuming the lower horizontal line is connected to a suitable voltage rail[/size]

If there is no pulse, and the whole is only supply with Dc and there are capacitors inside, how will the current move?
 
NascentOxygen said:
If T1 is in the active region, there will be current flowing✻ in RC1 and R at least.

✻ assuming the lower horizontal line is connected to a suitable voltage rail[/size]
Thanks, guys
If there is no negative pulse ,the whole circuit is only powered by Dc ,and there are capacitor inside, how will the current flow?
 
This sounds like a homework exercise.

It is a standard monostable multivibrator circuit. I am confident that a google search will
find its operation well-described. http://img811.imageshack.us/img811/5412/thgooglefriend1.gif
 
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