neazoi
Advanced Member level 6
Hello, I have an LC oscillator that uses LC in series as a resonant circuit. The L is connected to the VCC.
The addition of a diode in the before or after the L really distorts much the signal.
The oscillator requires a minimum of 7V to operate.
In order to electronically switch between different coils I have thought of another approach. Use a PNP transistor like 2n2907 between vcc and each coil and control their base electronically. Clean and stable DC will pass through the transistor if it is enabled, to the coil.
I have tried it with 9V and a 2n2907 and it works ok. But on 7.5v I measure the voltage at the collector of the 2n2907 and it is 4.5v. the drop is too much and the circuit does not work.
What should I do for operation of 7.5V? (oscillator works at 7V min, so only 0.5v max drop should be allowed)
The addition of a diode in the before or after the L really distorts much the signal.
The oscillator requires a minimum of 7V to operate.
In order to electronically switch between different coils I have thought of another approach. Use a PNP transistor like 2n2907 between vcc and each coil and control their base electronically. Clean and stable DC will pass through the transistor if it is enabled, to the coil.
I have tried it with 9V and a 2n2907 and it works ok. But on 7.5v I measure the voltage at the collector of the 2n2907 and it is 4.5v. the drop is too much and the circuit does not work.
What should I do for operation of 7.5V? (oscillator works at 7V min, so only 0.5v max drop should be allowed)
