Enrique15
Member level 3
Hello. This is my first topic in this forum.
I wonder if someone can help me with a question I have from some time ago.
When studying about oscillators using Op. Amp., they always teach you about how to calculate the value of resistors, capacitors, and other external elements, to get a particular frequency. But they never talk about the "External Voltage Supply" or voltage signals to make the amplifier to start generating an output voltage that will then generate an oscillation.
The question is:
Do Operational Amplifiers generate by themselves an output voltage enough to start an oscillation, without having any external voltage signal in any of its inverter or non inverter Input pins?
Of course I know that the Op. Amp. needs a V+ and V- voltage source in each of its V+ and V- pins. But those voltages are the ones that will be shown as the output voltages of the Op. Amp. after it senses an external voltage in its inverter or non inverter pins.
Why is that if not having any INPUT voltages, the amplifier generates an oscillating voltage (done with the resistors, capacitors and other elements attached to the circuit) ??? Where does the Op. Amp. gets voltage to generate OUTPUT voltage to start the oscillation ??
It's just like when I see a "crystal-with-Op.-Amp." oscillator schematic. It only has the crystal, two capacitors, the Op. Amp., one or two resistors, and that's it. Where is the Power Supply to activate the Op. Amp. or to activate the crystal ??
Well, that's the great question I have in my mind this days. Because after reading so much books and looking in internet pages, I couldn't find anything that can answer me this question.
Hope someone can help me "see the light" through this topic, jejejeje.
Thanks for any help you can give me.
Regards. :spoko:
I wonder if someone can help me with a question I have from some time ago.
When studying about oscillators using Op. Amp., they always teach you about how to calculate the value of resistors, capacitors, and other external elements, to get a particular frequency. But they never talk about the "External Voltage Supply" or voltage signals to make the amplifier to start generating an output voltage that will then generate an oscillation.
The question is:
Do Operational Amplifiers generate by themselves an output voltage enough to start an oscillation, without having any external voltage signal in any of its inverter or non inverter Input pins?
Of course I know that the Op. Amp. needs a V+ and V- voltage source in each of its V+ and V- pins. But those voltages are the ones that will be shown as the output voltages of the Op. Amp. after it senses an external voltage in its inverter or non inverter pins.
Why is that if not having any INPUT voltages, the amplifier generates an oscillating voltage (done with the resistors, capacitors and other elements attached to the circuit) ??? Where does the Op. Amp. gets voltage to generate OUTPUT voltage to start the oscillation ??
It's just like when I see a "crystal-with-Op.-Amp." oscillator schematic. It only has the crystal, two capacitors, the Op. Amp., one or two resistors, and that's it. Where is the Power Supply to activate the Op. Amp. or to activate the crystal ??
Well, that's the great question I have in my mind this days. Because after reading so much books and looking in internet pages, I couldn't find anything that can answer me this question.
Hope someone can help me "see the light" through this topic, jejejeje.
Thanks for any help you can give me.
Regards. :spoko: