2 votes

Designing a common emitter audio pre-amplifier

List out what you know The first thing I try to achieve well is listing out the details I think I know. In your case, I think you know these things: \$A_v=7\:\text{dB}\approx 2.24\times\$ \$\beta_{_\...
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  • 68.8k
2 votes

An over- and under-voltage protection system

The 555 timer IC contains a comparator (two, actually) so it's possible to coax it into acting as a under/over voltage detector if you power it from a regulated (reference) voltage. Here is one ...
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1 vote

Designing a common emitter audio pre-amplifier

Why are you overloading the circuit with a 350 ohms load? An audio preamp usually drives an amplifier with an input resistance that is 20 times or more the output impedance of the preamp. Then your ...
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  • 2,169
1 vote
Accepted

Graphing modes of BJT

In this type of graph the DC load line extents are based on two conditions, when the collector-emitter junction is an open circuit, and when it is a short circuit. The point where the DC load line ...
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  • 3,396
1 vote

Ring oscillator not oscillating

The 1Meg resistors are so high that the current gain of a typical BJT won't give a net gain around the loop of over unity, so no oscillation. MOSFETs don't have a problem with this high resistance. To ...
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  • 13

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