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1 vote

### How does a capacitor in an astable multivibrator turn off a BJT?

Introduction I am thrilled to answer this question, as it brings back fond memories from my high school days in the 60s. It was one of the first circuits I built, using PNP transistors and lamps in ...
• 17.8k
1 vote

### How does a capacitor in an astable multivibrator turn off a BJT?

Late answer, but consider this: Both inductors and capacitors store energy, and there always is a time element to their charging and discharging. It's the "dt" in the equations. Because of ...
• 21.6k
1 vote

### Calculating capacitor charging and discharge time using LM311 as Schmitt trigger astable multivibrator

I calculate the threshold voltages at 1.45V and 2.14V using an output voltage of 0.17V (low) and 5V (high), taking into account the 1K pullup (but not the 10k to the capacitor). Simulated values are 1....
• 410k
1 vote

### Calculating capacitor charging and discharge time using LM311 as Schmitt trigger astable multivibrator

First, we need to find the threshold voltage. If we assume that LM311 is LOW (0V) then the voltage at V+ will be equal to:  V_{TL} = V_{CC} * \frac{R_2||R_4}{R_1 + R_2||R_4} = 5V * \frac{7.96k\Omega}...
• 15.2k

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