**Oscillators: The Heartbeat of Electronics**

In this article, we will delve into the world of oscillators, electronic circuits that create periodic alternating voltage signals. These signals are used as a clock signal for devices or as a carrier wave for radio communication and other data exchange.

**Relaxation Circuits: A Classic Example**

One of the most popular oscillator types is the relaxation circuit, especially with RC components. The multivibrator is a classic example that demonstrates this principle. It uses two capacitors (C1 and C2) which get charged alternately through a resistor to a certain threshold voltage of the transistor. In this case, around 0.3 volts. This causes the transistor to become conductive and discharge capacitor C1 while the other one C2 gets charged. Once C2 reaches the threshold voltage, the cycle repeats with the other transistor, creating a rectangle waveform that is visualized by LEDs.

If you decrease the resistance or capacitance, the charging and discharging process would get shorter, and the frequency of the rectangle wave increases. This principle also implements the same core idea as the 555 timer, which consists of two comparators, two logic gates, and one RS flip-flop. These timers are super easy to use by connecting a 100nF capacitor, a 680 Ohm resistor, and a 150 kOhm potentiometer, creating a stable and variable rectangle wave.

**LC Resonators: Creating High Frequencies**

However, if we need even higher frequencies, we can use LC resonators, also known as LC tank circuits. Before diving into detail about these, it is recommended to watch the videos about capacitors and inductors. The capacitor gets charged up to the maximum voltage and has its maximum electrostatic energy stored. After disconnecting the power supply, the capacitor slowly discharges through the inductor. Since the current in the inductor cannot change instantly, it also slowly builds up until the coil reaches its maximum stored magnetic energy.

This energy then converts back into the electrostatic energy of the capacitor by charging it up in reverse and the cycle repeats again. Simultaneously, we also created a sine voltage and current along the way. However, this oscillation does not last that long because parasitic resistance is everywhere, converting some power into heat.

**Resonance Frequency**

We also see that the tank circuit oscillated with a specific frequency called the resonance frequency. This occurs when the reactance of the coil and capacitor are equal, canceling each other out as a consequence. The voltage or current in an LC circuit can exceed the initial applied values of the power supply but only near the resonance frequency.

**Finding the Right Energy Input**

To keep the oscillation going, we need to find a way to feed the circuit energy at the right time so that the oscillation does not stop. This can be achieved by connecting the output of the tank circuit to the input of an amplifier, like an npn transistor. By choosing the amplification factor just right, the output of the amplifier delivers a stable megahertz sine wave.

**Crystal Oscillators: The Most Stable Frequencies**

If we need even more stable frequencies, we can use crystal oscillators. These act just like LC resonators but also use the mechanical vibrations of a piezoelectric (PZT) crystal to create a stable signal. In this case, a 16 MHz signal is created. The necessary amplifier circuits are very similar to the one before, and you often see such crystals next to a microcontroller to set its processing speed.

**Conclusion**

In conclusion, oscillators are electronic circuits that can create periodic alternating voltage signals. There are various types of oscillators, including relaxation circuits, LC resonators, and crystal oscillators. Each type has its own strengths and weaknesses and is used in different applications. By understanding how these oscillators work, you can design and build your own electronic circuits that can perform a wide range of tasks.

WEBVTTKind: captionsLanguage: enif you've ever tried to find out just how fast your microcontroller can switch things on and off you might have thought to yourself where does this limitation come from or you might have thought what determines how fast my clock is ticking or what determines how often my multimeter refreshes its display values the answer to such timing related questions are so-called oscillators basically an electronic circuit that can create periodic alternating voltage signals like a square triangle or side wave these are then used as a clock signal for a device or as a carrier wave for radio communication or other data exchange through the air so in this video let's talk about the most popular oscillator types which you can also easily build at home let's get started first off relaxation circuits especially with RC components this aable multiv vibrator is a classic and rather simple example the main principle is about using two capacitors C1 and C2 which get charged alternating through a resistor to a certain threshold voltage of the transistor in this case around 0.3 vol volts this way the transistor becomes conductive and discharges capacitor C1 while the other one C2 gets charged once C2 then reaches the threshold voltage the cycle repeats with the other transistor and we successfully have created a rectangle waveform which is visualized by the LEDs if you would decrease the resistance or capacitance the charging and discharging process would get shorter and the frequency of the rectangle wave increases and I see which also implements the same core idea is the always popular 555 timer these consist of two comparators two logic ends and one logic orgate and the rs flip-flop so not that easy to explain right now but on the other hand super easy to use by connecting a 100 nanr capacitor a 680 Ohm resistor and 150 kilohm potentiometer we can create a stable and variable rectangle wave Again by charging and discharging the capacitor periodically in this case though the threshold values are 66 and 33% of the supply voltage and of course you can increase the frequency again up to a certain degree but eventually at some point it is not that Pleasant to look at that is where we use LC resonators AKA LC tank circuits toate create very high frequencies but before going into detail about those I recommend that you should watch my videos about capacitors and inductors firstly the capacitor gets charged up to the maximum voltage and has its maximum electrostatic energy stored after disconnecting the power supply the capacitor slowly discharges through the inductor and since the current th inductor cannot change instantly it also slowly builds up until the coil has reached its maximum of stored magnetic energy this energy then converts back into the electrostatic energy of the capacitor by charging it up in reverse and the cycle repeats again simultaneously we also created a sign voltage and current along the way but in reality this oscillation does not last that long because parasitic resistance is everywhere and converts some of the power into heat we also see that that the tank circuit oscillated with a specific frequency which is called the resonance frequency this occurs when the reactant of the coil and capacitor are the same and cancel each other out as a consequence the voltage or current in an LC circuit can exceed the initial applied values of the power supply but only near the resonance frequency but that is not the main point right now we still need to find a way to feed the circuit energy at the right time so that the oscillation does not stop this can be achieved by connecting the output of the tank circuit to the input of an amplifier like this npn transistor by choosing the amplification Factor just right the output of the amplifier delivers a stable megahertz sine wave but as a side notes building such oscillators on a breadboard is not recommended due to rather loose connections and parasitic capacitance just like the RC methods we can change the inductance and capacitance to create all kinds of different frequencies necessary for different tasks but if we need even more stable frequencies we can also use a crystal oscillator it acts just like an LC resonator but also uses the mechanical vibrations of a pzo crystal and creates in this case a stable 16 MHz signal the necessary amplifier circuits is very similar to the one before and you often see such crystals next to a microcontroller to set its processing speed and with that being said you already know quite a bit about oscillators I hope you learned something new if so don't forget to like share and subscribe that would be awesome consider supporting me through my patreon campaign to keep such videos coming stay creative and I will see you next timeif you've ever tried to find out just how fast your microcontroller can switch things on and off you might have thought to yourself where does this limitation come from or you might have thought what determines how fast my clock is ticking or what determines how often my multimeter refreshes its display values the answer to such timing related questions are so-called oscillators basically an electronic circuit that can create periodic alternating voltage signals like a square triangle or side wave these are then used as a clock signal for a device or as a carrier wave for radio communication or other data exchange through the air so in this video let's talk about the most popular oscillator types which you can also easily build at home let's get started first off relaxation circuits especially with RC components this aable multiv vibrator is a classic and rather simple example the main principle is about using two capacitors C1 and C2 which get charged alternating through a resistor to a certain threshold voltage of the transistor in this case around 0.3 vol volts this way the transistor becomes conductive and discharges capacitor C1 while the other one C2 gets charged once C2 then reaches the threshold voltage the cycle repeats with the other transistor and we successfully have created a rectangle waveform which is visualized by the LEDs if you would decrease the resistance or capacitance the charging and discharging process would get shorter and the frequency of the rectangle wave increases and I see which also implements the same core idea is the always popular 555 timer these consist of two comparators two logic ends and one logic orgate and the rs flip-flop so not that easy to explain right now but on the other hand super easy to use by connecting a 100 nanr capacitor a 680 Ohm resistor and 150 kilohm potentiometer we can create a stable and variable rectangle wave Again by charging and discharging the capacitor periodically in this case though the threshold values are 66 and 33% of the supply voltage and of course you can increase the frequency again up to a certain degree but eventually at some point it is not that Pleasant to look at that is where we use LC resonators AKA LC tank circuits toate create very high frequencies but before going into detail about those I recommend that you should watch my videos about capacitors and inductors firstly the capacitor gets charged up to the maximum voltage and has its maximum electrostatic energy stored after disconnecting the power supply the capacitor slowly discharges through the inductor and since the current th inductor cannot change instantly it also slowly builds up until the coil has reached its maximum of stored magnetic energy this energy then converts back into the electrostatic energy of the capacitor by charging it up in reverse and the cycle repeats again simultaneously we also created a sign voltage and current along the way but in reality this oscillation does not last that long because parasitic resistance is everywhere and converts some of the power into heat we also see that that the tank circuit oscillated with a specific frequency which is called the resonance frequency this occurs when the reactant of the coil and capacitor are the same and cancel each other out as a consequence the voltage or current in an LC circuit can exceed the initial applied values of the power supply but only near the resonance frequency but that is not the main point right now we still need to find a way to feed the circuit energy at the right time so that the oscillation does not stop this can be achieved by connecting the output of the tank circuit to the input of an amplifier like this npn transistor by choosing the amplification Factor just right the output of the amplifier delivers a stable megahertz sine wave but as a side notes building such oscillators on a breadboard is not recommended due to rather loose connections and parasitic capacitance just like the RC methods we can change the inductance and capacitance to create all kinds of different frequencies necessary for different tasks but if we need even more stable frequencies we can also use a crystal oscillator it acts just like an LC resonator but also uses the mechanical vibrations of a pzo crystal and creates in this case a stable 16 MHz signal the necessary amplifier circuits is very similar to the one before and you often see such crystals next to a microcontroller to set its processing speed and with that being said you already know quite a bit about oscillators I hope you learned something new if so don't forget to like share and subscribe that would be awesome consider supporting me through my patreon campaign to keep such videos coming stay creative and I will see you next time