Post History
A while ago I made a question about the monostable multivibrator .Lets get a picture of it: When switch is closed it enters its unstable state and it eventually returns to the stable state Howe...
#3: Question closed
by
Olin Lathrop
·
2021-10-10T19:55:54Z (about 3 years ago)
#2: Post edited
by
Canina
·
2021-10-08T21:44:55Z (about 3 years ago)
Confusion with Wikipedia article on multivibrator circuit
- A while ago I made a question about the monostable multivibrator .Lets get a picture of it:
- 
- When switch is closed it enters its unstable state and it eventually returns to the stable state
However Wikipedia states that this design is retriggerable , the output (voltage of collector of Q2)will stay high as long as the input is active, and then remain high for the relaxation period starting when the input is released.- However I cant understand why it is.
When the circuit gets powered up due to R4 Q1 becomes saturated which turns off Q2.At the same time C1 is being charged to a voltage of V1-VBE(Q1).- This is the stable state.
- When the switch is closed Q1 turns off and Q2 becomes saturated and the capacitor is being charged in the opposite direction than before until it reaches approximately 0.6V in the opposite direction which turns on Q1 and the circuit returns to the stable state.
- A while ago I made a question about the monostable multivibrator .Lets get a picture of it:
- 
- When switch is closed it enters its unstable state and it eventually returns to the stable state
- However Wikipedia states that this design is retriggerable , the output (voltage of collector of Q2) will stay high as long as the input is active, and then remain high for the relaxation period starting when the input is released.
- However I cant understand why it is.
- When the circuit gets powered up due to R4 Q1 becomes saturated which turns off Q2. At the same time C1 is being charged to a voltage of V1-VBE(Q1).
- This is the stable state.
- When the switch is closed Q1 turns off and Q2 becomes saturated and the capacitor is being charged in the opposite direction than before until it reaches approximately 0.6V in the opposite direction which turns on Q1 and the circuit returns to the stable state.
#1: Initial revision
by
MissMulan
·
2021-10-08T18:58:46Z (about 3 years ago)
Confusion with Wikipedia article on multivibrator circuit
A while ago I made a question about the monostable multivibrator .Lets get a picture of it:  When switch is closed it enters its unstable state and it eventually returns to the stable state However Wikipedia states that this design is retriggerable , the output (voltage of collector of Q2)will stay high as long as the input is active, and then remain high for the relaxation period starting when the input is released. However I cant understand why it is. When the circuit gets powered up due to R4 Q1 becomes saturated which turns off Q2.At the same time C1 is being charged to a voltage of V1-VBE(Q1). This is the stable state. When the switch is closed Q1 turns off and Q2 becomes saturated and the capacitor is being charged in the opposite direction than before until it reaches approximately 0.6V in the opposite direction which turns on Q1 and the circuit returns to the stable state.