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Explanation for a circuit?
Here is the link:
www.circuitstoday.com/fm-radio-jammer
How were the values of the all the capacitors and resistors decided (c2, c3, c4, r1, r2, r3)?
Why a npn transistor and not a pnp?
What would happen if any of the resistors and/or capacitors had their value changed.
And whats the use of c2, c3, c4 ( especially c3) in the circuit?
I want to understand this before I actually sit down to make it and test it.
3 Answers
- ?Lv 78 years ago
C2 provides some phase shift, C1 is a tuning cap, C3 provides an AC short to ground, C4 is a bypass cap. The resistors were chosen to establish the DC bias and gain of the transistor. It won't matter if they change a little. You could make a circuit like this with a PNP transistor, but the biasing would have to reverse.
- Alok TLv 58 years ago
C1 is the supply filtering capacitor and its value is not going to affect the performance. R1 and R2 are the voltage divider and they decide the base voltage and c3 is a filter capacitor for the base voltage. L1 and C1 decides the frequency of the oscillator. R3 provides the emiter voltage and c2 is feed back circuit for the oscillator.
- Anonymous8 years ago
When in doubt, Get the books out.