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@@Hb1609Hashim Frequency Response is a special case of Laplace transfer function (s domain analysis) by substituting S=j*2*pi*f .

@Hb1609Hashim Good question. The transfer function of this op amp circuit indicates a Lowpass filter as explained at minute 8:00 given the specific values of two Poles and one zero in this example. To visualize it, you can draw a Bode plot of the transfer function. I suggest watching the following videos: How to find Transfer Function of an amplifier from Bode Plot th-cam.com/video/NtiXDdFdCGY/w-d-xo.html Find LTI System Transfer Function given the Bode Frequency Response th-cam.com/video/zgdUwZcUEW0/w-d-xo.html Filter Design using Op Amp and Bode plot Example th-cam.com/video/n_VX6WvPJPI/w-d-xo.html Frequency Response, Bode Plot, Transfer Function: BandPass Analog Filter th-cam.com/video/vZFkPeDa1H8/w-d-xo.html I hope the explanation and these additional videos are helpful in answering your questions.

@STEMprof ok I will do, thanks for replying

Thanks for your interest in my videos. Sure, which specific circuits or topics do you have in mind? I suggest watching the following tutorial videos: Sallen-Key Analog Filter Design Tutorial th-cam.com/video/KwUnQXbk7gM/w-d-xo.html Laplace Transform Example and S-domain circuit analysis: th-cam.com/video/ps8N5TPM_qU/w-d-xo.html How to find Bode Plot, Freq Response, Transfer Function of Analog Filters th-cam.com/video/vZFkPeDa1H8/w-d-xo.html Power Amplifier Design (Class A) with Transformer Explained th-cam.com/video/gKlJrqGqeCI/w-d-xo.html Universal Analog Filter Design th-cam.com/video/2J-0msXZE2o/w-d-xo.html Are these tutorial videos helpful?

@STEMprof thanks, I will watch all😁

Generally speaking, yes. However, practically speaking, it depends on the type of load. The voltage-controlled current source, also known as a transconductance amplifier, explained in this video, is designed to provide up to 1000 mA of current to the load with a maximum of 8V, given a 10V supply. This indicates that the largest load resistor in this scenario is roughly 8 ohms. The P-channel power MOSFET must be selected carefully, considering the target load and power consumption requirements. Here are a few related videos to watch: Temperature-Independent Current Circuit Design with Op Amp, BJT, Zener, Schottky Diodes th-cam.com/video/hFbnjbddUvs/w-d-xo.html Programmable Current Source Design with Op Amp, Zener Diode and Digital Potentiometer th-cam.com/video/R1x6B0TczWk/w-d-xo.html On-Chip BJT Current Source Design th-cam.com/video/Rs7gEMk03dw/w-d-xo.html Push-Pull Power Amplifier with Darlington Transistors th-cam.com/video/866MYibo8yE/w-d-xo.html I hope these videos are helpful.

I've one question though. What are the advantages of these kinds of circuits? We could achieve the same gain in one stage.

​ @ami6packs You're welcome! Glad to hear that your liked my video.

​@@ami6packs Good question. In this video example, the first op amp inverts input voltage by providing a gain of -2 while the middle op amp acts as an inverting voltage summer with negative unity gain and the third op amp acts as a non-inverting amplifier with a gain of 3. There are of course multiple ways to design this circuit. Here are a few related videos: Summing Amplifier (non-inverting Analog Adder) th-cam.com/video/zPnaCPOUw5E/w-d-xo.html 1x, 10x, 100x, 1000x Switched-Gain Instrumentation Amplifier th-cam.com/video/9-MLqyewXW8/w-d-xo.html Instrumentation Amplifier with Electronic Gain Control th-cam.com/video/C4tghZ-q6Zs/w-d-xo.html Summing Integrator vs Difference Integrator with Operational Amplifier th-cam.com/video/_5NT4mQxVEo/w-d-xo.html I hope these these videos are helpful.

For practical amplifier design, op amps and JFETs need to be selected carefully and if need be with proper temperature compensation. I suggest using zero-drift low-noise CMOS Op Amps possibly with internal temperature compensation from Texas Instruments or Analog Devices. It is also recommended to have small feedback capacitor between the output and negative input terminals of each op amp. Here are a few related videos: Gain & CMRR of Instrumentation Amplifier Explained th-cam.com/video/Bw29QjHHzGo/w-d-xo.html PT100 RTD Temperature Sensor Explained with Error Compensation th-cam.com/video/Fsd-X69awFk/w-d-xo.html Anti-Log Analog Computer with Temperature Compensation th-cam.com/video/kk2c7Gk3nW4/w-d-xo.html I hope these videos are helpful.

Good question. For practical amplifier design, all components including op amps need to be selected carefully. I suggest using zero-drift low-noise CMOS precision Op Amps from Texas Instruments or Analog Devices. When carefully selected, drift currents and voltages of the CMOS op amps are on the order of tens of nano amps or nano volts. For related videos please see: Thermometer Sensor Circuit Explained th-cam.com/video/5jmbZ9ak6EI/w-d-xo.html PT100 RTD Temperature Detector with Error Compensation th-cam.com/video/Fsd-X69awFk/w-d-xo.html Temperature-Compensated Programmable Current Source Circuit Design with Zener Diode, BJT Transistors th-cam.com/video/QY48IQXJIRI/w-d-xo.html Thermometer Circuit Design with Op Amp and BJT transistor th-cam.com/video/55YsraFE0rg/w-d-xo.html I hope this is helpful.

You are welcome. Glad that you liked my explanation in this video. For practical amplifier design, op amps needs to be selected carefully. I suggest using zero-drift low-noise CMOS Op Amps from Texas Instruments or Analog Devices. It is also recommended to have small feedback capacitors, say 30-100 picofarads between the output and negative input terminals of each op amp. DC biasing of the input terminals of op amps is also important and should be set properly to half supply voltage in case of a single-supply design. Here are a few more electronic amplifier videos: Gain & CMRR of Instrumentation Amplifier Explained th-cam.com/video/Bw29QjHHzGo/w-d-xo.html 1x, 10x, 100x, 1000x Switched-Gain Instrumentation Amplifier th-cam.com/video/9-MLqyewXW8/w-d-xo.html Instrumentation Amplifier Explained th-cam.com/video/Yq767et8BbY/w-d-xo.html Variable Gain Instrumentation Amplifier for designing Thermometer Current Source th-cam.com/video/Ggf0yCaTTiY/w-d-xo.html Instrumentation Amplifier design with Differential Instrumentation Amplifier with BJT transistor th-cam.com/video/2xJpqfexsPg/w-d-xo.html I hope these videos are helpful.

You're welcome, Samuel. Glad that my videos are useful. Thank you for sharing your thoughts. Here are a few related electronic amplifier videos: 1x, 10x, 100x, 1000x Switched-Gain Instrumentation Amplifier th-cam.com/video/9-MLqyewXW8/w-d-xo.html Gain & CMRR of Instrumentation Amplifier Explained th-cam.com/video/Bw29QjHHzGo/w-d-xo.html Variable Gain Instrumentation Amplifier for designing Thermometer Current Source th-cam.com/video/Ggf0yCaTTiY/w-d-xo.html Instrumentation Amplifier Explained th-cam.com/video/Yq767et8BbY/w-d-xo.html I hope these videos are interesting as well.

@38911bytefree you're welcome. Glad that you liked this power amplifier Design Video. Here is a related video: Push-Pull Power Amplifier with Darlington Transistors th-cam.com/video/866MYibo8yE/w-d-xo.html For more analog circuits videos see: th-cam.com/play/PLrwXF7N522y4c7c-8KBjrwd7IyaZfWxyt.html Playlist. I hope these Circuit design videos are interesting as well. 🙋‍♂️

Thank you! Glad that my video is helpful. Here are a few related videos in circuit playlist: BandPass Sallen-Key Filter Design th-cam.com/video/lsM09pcrRVE/w-d-xo.html , Lowpass Butterworth Filter: th-cam.com/video/UzCjkwqy-9w/w-d-xo.html Universal Analog Filter Design th-cam.com/video/2J-0msXZE2o/w-d-xo.html I hope these videos are helpful.

My pleasure, Glad that you liked my video. Here are a few related circuit videos: Band-Pass Sallen-Key Filter Design th-cam.com/video/lsM09pcrRVE/w-d-xo.html , Lowpass Butterworth Filter: th-cam.com/video/UzCjkwqy-9w/w-d-xo.html , Universal Analog Filter Design th-cam.com/video/2J-0msXZE2o/w-d-xo.html . Thank you.

@erikev Thank you for sharing your insights. I'm glad you liked the circuit and my video. You are correct that the most accurate way to measure RMS is through direct measurement, rather than the inferred method of first measuring the peak and then using the peak-to-RMS formula. The latter assumes the waveform is perfectly sinusoidal, which may not always be practically accurate. Here are a few related videos: Full-wave Rectifier AC to DC Converter th-cam.com/video/ogZVEGgU0JA/w-d-xo.html AC/DC Adapter Circuit with Op Amp and Diode th-cam.com/video/3rXW5bPlgd8/w-d-xo.html Analog Logarithm Calculator with Op Amp and Diode th-cam.com/video/w4DuaCJGRRY/w-d-xo.html I hope these circuit videos are interesting as well.

Thanks John for watching and sharing your experiences. Glad to hear that your variant of this Push-Pull amplifier with an additional Class A amplifier worked nicely to drive 120V. If you are using this design, depending on the type of your Op Amp and Transistors, you need to adjust the value of resistors especially at the output of the Op Amp (for example, the 50 K ohm and 500 ohm resistors.) The choice of Op Amp is also important. Be sure to have a low drift, high drive CMOS Op Amp. To watch related videos: Push-Pull Power Amplifier Design with Darlington and Sziklai transistor pairs th-cam.com/video/866MYibo8yE/w-d-xo.html Voltage Regulator Design with push pull output th-cam.com/video/CJl-urzeiTo/w-d-xo.html More Power Amplifiers & Voltage Regulators Videos are in th-cam.com/play/PLrwXF7N522y4vWr-8XRBqxpi5idFDE9BV.html video playlist.

Proper Transistors selection is important. Please be sure to review your BJT transistors' datasheets to see if they are appropriate for your target design. You can also purchase Darlington transistors online. For more video examples see: Push-Pull Power Amplifier Design with Op Amp th-cam.com/video/8BFzsi7-Vbs/w-d-xo.html High Voltage Push-Pull Power Amplifier with Darlington transistors th-cam.com/video/C9Hse91r5sA/w-d-xo.html I hope these videos are helpful.

No, the cold junction is not only the point where the bare thermocouple wires connect to copper. The term "cold junction" refers to the reference junction, typically the location where the temperature is known or controlled. In a thermocouple system, the cold junction is usually at the point where the thermocouple wires are connected to a measuring device or reference material (such as copper or another metal). But if there are multiple junctions formed by different metal pairs in the circuit, each additional junction can also influence the measurement. When thermocouple wires are connected to other metals (like copper in the measuring device), each junction between dissimilar metals creates a potential difference, which can contribute to the overall voltage (e.g. series voltages that add up). The cold junction compensation method is used to account for this, ensuring that the temperature at the connection point is accurately represented in the measurement. Therefore, the cold junction is primarily considered where the temperature is controlled and known, and where compensation for other junctions in the system is applied, not just where the thermocouple connects to copper. I hope this is helpful. Here are a few related circuit videos: Thermometer Sensor Circuit Explained th-cam.com/video/5jmbZ9ak6EI/w-d-xo.html PT100 RTD Temperature Detector with Error Compensation th-cam.com/video/Fsd-X69awFk/w-d-xo.html Thermometer Circuit Design with Op Amp and BJT transistor th-cam.com/video/55YsraFE0rg/w-d-xo.html

@@STEMprofThank you! So while other junctions will influence measurements to some extent, is junction with bare thermocouple wires more likely to introduce the most error? Since it probably is closest to the measured object(larger temperature difference with ambient) and due to the fact that it has different pairs of metals for example chromel to copper and alumel to copper, that have different Seebeck coefficients(other junctions are more likely to be two similar pairs, something like two pairs of copper to bronze that have the same Seebeck coefficients and will compensate each other if their temperature is the same)

@@qt1qg You're welcome! Good points regarding thermocouple measurements and the potential sources of error due to additional junctions. Yes, the junction where the bare thermocouple wires connect to copper is more likely to introduce the most error. This is because this junction is exposed to the largest temperature difference between the measured object (the hot junction) and the ambient environment, which can create a significant thermoelectric potential. Also, as you mentioned, the metals used in the thermocouple (such as chromel and alumel) and the metal the thermocouple connects to (like copper) have different Seebeck coefficients, which means they will generate different voltage contributions depending on their temperature difference. This results in potential measurement errors unless properly compensated. The junction formed by two similar metal pairs (like copper to copper, or brass to brass) would likely have less impact, as the Seebeck coefficients of similar materials are closer, and their temperature-induced voltages can cancel each other out more effectively. This is why the system is usually designed with materials that have well-matched properties for minimizing such errors. In practical thermocouple systems, cold junction compensation is employed to correct for these types of errors, by either measuring the temperature at the cold junction directly (using an RTD or say a thermistor) or using a known reference temperature to adjust the reading accurately. I hope this explanation clarifies things a bit further.

Soldering irons, such as those using T12, JBC, or Hakko 900 series tips, often don't explicitly perform cold junction compensation in the same way thermocouple systems do, because they typically don't use thermocouples for temperature sensing. Instead, they rely on a different approach like the PT100 RTD Temperature Detector with Error Compensation th-cam.com/video/Fsd-X69awFk/w-d-xo.html to manage temperature and ensure accuracy. Here's how they work: 1-- Temperature Control Mechanism: Most modern soldering irons like the T12, JBC, and Hakko 900 series use a sensor (usually a thermistor or RTD) placed at the tip or very close to the tip to measure the temperature directly at the point of soldering. This sensor is crucial because it directly monitors the temperature of the tip in real-time. A related video is Thermometer Circuit Design with Op Amp and BJT transistor th-cam.com/video/55YsraFE0rg/w-d-xo.html 2-- Cold Junction Compensation (or Equivalent): The handle of the soldering iron, including the cold end of the tip, can indeed reach higher temperatures (around 50°C, as you mentioned), which might cause concerns about temperature readings being influenced by ambient heat. However, soldering irons don't typically use thermocouples for sensing the temperature, so the issue of cold junction compensation (which primarily applies to thermocouples) is less of a concern. Instead of compensating for the cold junction as thermocouples would, the system relies on sensor calibration. The sensor used in the soldering iron (often a thermistor or an RTD) is calibrated to account for the temperature at the tip and its surroundings. Even though the handle may get warm, the system compensates for the temperature through direct measurement at the tip, ensuring it maintains the correct soldering temperature by adjusting power to the heating element. In summary, soldering irons do not need cold junction compensation in the traditional thermocouple sense because they do not use thermocouples to measure the temperature. They rely on direct temperature measurement at the tip using sensors like thermistors or RTDs and compensate for ambient and handle temperatures through sensor calibration and power control mechanisms. The heating system ensures the tip maintains the correct temperature based on real-time feedback from the sensor at the tip itself. Watch this video th-cam.com/video/5jmbZ9ak6EI/w-d-xo.html to see more about Thermometer Sensor Circuit Design.

​@@STEMprof Thank you for the response! I recently found out that original JBC tips are TC based and have compensation inside the cartridge, t12 tips are also TC-based and original Hakko handle has RTD inside for software based compensation. 900 series are RTD based(don't know why they did not use RTD in T12 and JBC). Clone cartridges and handles probably don't have any compensation. I know that some soldering stations that use T12 cartridges have thermal sensor on the board or use MCU with built in thermal sensor, is it possible to achieve any kind of accurate regulation by estimating cold junction temperature based on thermocouple readings and ambient temperature with some kind of empirically discovered formula?

@@qt1qg You're welcome! Your insights are spot on about how different temperature sensing technologies used in soldering irons. To clarify the part about achieving accurate regulation by estimating cold junction temperature using thermocouple readings and ambient temperature: yes, it’s possible in theory, but it’s definitely more complex and less reliable than using a direct measurement approach say using thermistors or RTDs (Resistance Temperature Detectors) similar to the th-cam.com/video/Fsd-X69awFk/w-d-xo.html video discussing PT100 RTD Temperature Detector with Error Compensation to manage temperature and ensure accuracy. In soldering stations using thermocouples (like those with T12 or JBC tips as you stated), cold junction compensation is typically achieved using internal compensation circuitry that accounts for the ambient temperature at the cold junction (the connection point between the thermocouple and the board). This allows the system to correctly interpret the temperature difference measured by the thermocouple. However, if you're estimating the cold junction temperature based on ambient temperature and thermocouple readings, it would require a precise mathematical model or empirical formula, which might not be universally accurate for all setups. This model would need to account for factors like thermal resistance, environmental factors, and how the tip and handle are thermally coupled. Even with this, the result could vary between different soldering irons and environments. On the other hand, as you mentioned, the Hakko 900 series and T12 tips use RTDs or thermistors that are typically placed near the tip. These sensors provide much more accurate and stable temperature measurements, since they don’t rely on interpreting a voltage difference like thermocouples. In these cases, ambient temperature and handle heat still need to be considered, but the MCU or onboard temperature sensor can use software-based compensation to account for the temperature variation. To summarize, while estimating cold junction temperature with thermocouple readings and ambient temperature is a theoretical approach that could work with proper calibration, most modern soldering stations with RTDs or thermistors achieve much more accurate and reliable regulation using direct temperature feedback from the tip. This eliminates the need for complex compensation methods, making temperature control easier to manage and maintain. I hope this follow-up explanation is helpful.

You're welcome. Glad to hear that my video was useful for your project. Regarding your questions You're welcome! I'm glad to hear that my video was helpful for your project. To address your question, I recommend watching the th-cam.com/video/ENq39EesfPw/w-d-xo.html video of an Op Amp-based Analog Circuit to compute solutions for differential equations with programmable coefficients. This video might provide more insight into your specific case. In regard to the issue you're facing with amplifying the DC component in third-order circuits, adding resistors in parallel with the capacitors is surely a good starting point. The problem you're encountering is often related to the input offset voltage and the bias currents of the op amp, which can create unwanted errors in the DC performance, particularly when working with high-order circuits. Here are a few suggestions to improve the DC performance of your circuit: Use Op Amps with Low Offset Voltage: Ensure that the operational amplifier you're using has low input offset voltage (ideally in the microvolt range) because offset voltage can affect your DC measurements and steady-state behavior. For precision applications, quad op amp package OPA 4189 CMOS op amp www.ti.com/product/OPA4189 should be a very good choice, as it offers very low drift and near zero offset voltage. Using a quad op amp package can also help minimize noise and maintain consistency across multiple channels. See Texas Instruments' precision Op Amps matrix www.ti.com/amplifier-circuit/op-amps/precision/overview.html for more choices. Offset Nulling: Many precision op amps have pins dedicated to offset adjustment, sometimes called "offset legs" or "offset null pins." These pins allow you to apply a small external voltage to nullify the op amp's offset. If your op amp has offset pins (e.g. LM324), you can connect a small potentiometer to these pins to manually null the offset and improve the DC performance. Some modern op amps, like the OPA4189 or OPA333, don't have offset null pins but achieve very low offset voltage through internal trimming. Add a Low-Pass Filter at the Output: Since you're dealing with a third-order circuit, higher-order circuits can have more sensitivity to small DC offsets or noise. Adding a low-pass filter to the output can help smooth out any remaining DC offset by filtering out unwanted high-frequency components that might be interfering with your signal. Proper Biasing and Component Selection: When you're using large resistors in parallel with capacitors to improve the DC gain, it's important to choose resistors with low noise and low drift, as well as capacitors with tight tolerances. Temperature variations or component tolerances can introduce unwanted drift, so ensure that the components you're using are rated for low temperature coefficients and high precision. Temperature Effects: High-order circuits are particularly susceptible to temperature-induced drift. Make sure to use components rated for stability over the temperature range you're operating in, and consider using op amps with built-in temperature compensation if you're working in environments where temperature changes might be a concern. By following these recommendations, you should be able to reduce the DC offset and improve the stability of your circuit, especially with higher-order systems. It’s always good practice to double-check your op amp's datasheet for specific features like input offset voltage and temperature coefficients, as well as any internal compensation mechanisms that can help optimize performance. I hope this is helpful.

@@STEMprof Thank you very much for your reply. Buying new Op Amps worked very well. I tried the low pass filter, but it overloaded the circuit a bit. Thank you again for your videos!

@@bananaswingingbeard You're welcome. Glad to hear that the new op amp worked well. 👍 Hope you enjoy the rest of videos as well. Happy holidays!

@@STEMprof Happy holidays too! I'm from France so my holidays are in a few weeks but thank you!

@@bananaswingingbeard je vous souhaite une bonne et saine année pleine de circuits passionnants :)

You're welcome! If you found the Dual Op Amp Bridge Audio Amplifier video helpful, you might also like the Electric Guitar Amplifier to XLR Audio Signal video th-cam.com/video/X4y8cwZdGEk/w-d-xo.html, where I explain amplifying audio signals for instruments like electric guitars, and show how to properly interface with XLR outputs. If you're interested in learning about electronic gain control for amplifiers, I have a couple of videos that explain how to manage gain electronically. You might find Op Amp Amplifier with Electronic Gain Control th-cam.com/video/NoNgQpbj77Y/w-d-xo.html and the VCA Voltage-Controlled Attenuator Overview video th-cam.com/video/cFzYZsPEtP0/w-d-xo.html useful. These videos will provide you with further insight into amplifier design, signal control, and practical applications in audio systems. I hope you find them interesting as well.

Thank you for your kind words! I'm glad to hear that you've found the series helpful and that the explanations are making a positive impact on your learning. It's great to know that the practical design insights are proving valuable to you! I think you'll also find the related video th-cam.com/video/866MYibo8yE/w-d-xo.html on the Push-Pull Amplifier with Darlington and Sziklai Transistors interesting as it explores a similar concept using different transistor configurations with more examples in the th-cam.com/play/PLrwXF7N522y4vWr-8XRBqxpi5idFDE9BV.html Power Amplifiers & Voltage Regulators playlist where you'll find a variety of related circuits and explanations. I hope you find these videos interesting as well as you explore more in-depth analog circuit design.

@samuelk3076 You're welcome! and thank you. Glad that you liked this rectifier video. Here are links to related op amp circuit videos: AC/DC converter th-cam.com/video/4aG5NYX8tGo/w-d-xo.html Precision Rectifier th-cam.com/video/2eAsJbTBkQA/w-d-xo.html Triangle Oscillator circuit th-cam.com/video/JF5Up_cuL9k/w-d-xo.html I hope these videos are interesting as well.

Thank you for your feedback, and I appreciate your constructive comments! I'm glad to hear that you found the presentation useful otherwise. Your input is valuable for making the content easier to follow. I understand how it can be challenging to follow along when the cursor isn't highlighted, and the text is small. I'll take this into account for future videos and see how I can improve the experience by highlighting the cursor and adjusting the text size for clarity. Here are a few related videos: Instrumentation Amplifier with Electronic Gain Control th-cam.com/video/C4tghZ-q6Zs/w-d-xo.html Voltage-Controlled Attenuator Overview th-cam.com/video/cFzYZsPEtP0/w-d-xo.html Thanks again.

@schnullertroll4173 You're welcome. Glad that you liked this Instrumentation Amplifier video. Regarding your question about the current flowing through the transistor's collector and 5.6 K ohm resistor, please watch the video at around minute 15:12 th-cam.com/video/2xJpqfexsPg/w-d-xo.htmlfeature=shared&t=912 when this is explained. For a related video, see th-cam.com/video/cFzYZsPEtP0/w-d-xo.html video that explains how VCA Electronic Gain Control works. I hope this is helpful.

@@horacepoon7044 You're welcome! Glad that this power amplifier video is helpful. Related videos are: Push-Pull Power Amplifier Design with Darlington and Sziklai transistor pairs th-cam.com/video/866MYibo8yE/w-d-xo.html Voltage Regulator Design with push pull output th-cam.com/video/CJl-urzeiTo/w-d-xo.html More Power Amplifiers & Voltage Regulators Videos are in th-cam.com/play/PLrwXF7N522y4vWr-8XRBqxpi5idFDE9BV.html video playlist.

@@ibrahimcetin153 You are welcome. Glad that this video is helpful. The Generalization of Karatsuba Algo, Toom-Cook (Toom3) is also explained with Examples in this follow-up video th-cam.com/video/1XiSyNzMX6Q/w-d-xo.html that I hope is interesting as well.

You're welcome. Glad that you like the explanation in this video. For more Electronic Amplifier examples see: Instrumentation Amplifier with Electronic Gain Control th-cam.com/video/C4tghZ-q6Zs/w-d-xo.html VCA Electronic Gain Control explained th-cam.com/video/cFzYZsPEtP0/w-d-xo.html Analog Multiplier Circuit th-cam.com/video/VP53A2zpVMQ/w-d-xo.html Push-Pull Power Amplifier Design with Op Amp, Sziklai Darlington Transistors th-cam.com/video/8BFzsi7-Vbs/w-d-xo.html I hope these Circuit videos are interesting as well.

Glad that this Digital Stethoscope Amplifier is helpful. I highly recommend using a zero offset low noise CMOS Op Amp for this design. Here are a few related signal conditioning videos: EKG ECG Amplifier with Right Leg Drive Explained th-cam.com/video/1c7KGXPs4do/w-d-xo.html Electric Guitar Amplifier to XLR Audio Signal th-cam.com/video/X4y8cwZdGEk/w-d-xo.html Bridge Audio Amplifier Explained th-cam.com/video/EDpu6urAtHA/w-d-xo.html Thermocouple Amplifier with Cold Junction Compensation Explained th-cam.com/video/-BsDLBI166U/w-d-xo.html

@m.sheriff1 You are welcome. Here are a few related circuit videos: Op Amps and Resistance Ladder Network th-cam.com/video/dx95Y0CBtnU/w-d-xo.html Resistance of infinite ladder resistor network th-cam.com/video/w96ooJty1Ic/w-d-xo.html Digital to Analog Converter Design with Resistor Ladder Explained th-cam.com/video/Y1H8HrrD4mQ/w-d-xo.html I hope these videos are interesting as well.

My pleasure. Glad that you like this Voltage to Current Converter Video. For another MOSFET circuit Video see "How to design a charger voltage regulator" th-cam.com/video/NdfyHoxjKrY/w-d-xo.html . Regarding your question, NMOS and PMOS transistors are active electronic devices (that require to be properly biased to work) in contrast with passive components like resistors and capacitors. Please watch the video at minute 11:28 when source terminal of NMOS and source terminal of PMOS are marked on the circuit diagram. For NMOS, the gate voltage needs to be higher than the source voltage by at least Threshold voltage (Vt) to turn on the NMOS. But for PMOS, the gate voltage needs to be less than the source voltage by at least the the magnitude of the threshold voltage in order to turn on the PMOS transistor.

Depends on your target application. Say, for Audio Signal Processing, the signal frequency range is ~50 Hz to 20 kHz. So, a clock frequency of say 500 kHz or higher should be proper. Capacitors in the range of ~5nF to 10nF should be fine assuming switch-on resistance of NMOS transistor less than 100 Ohms (check your transistor datasheet). To be on the safe side, your NMOS switching transistors should have a max switching frequency of at least a few MHz. Lastly, given the clock frequency is not that high, conservatively select a zero offset low noise CMOS Op Amp with a slew rate 20 times faster than your clock frequency. For example, if your clock rate is 500 kHz, then select Op Amp with slew rate of peak-peak (say 5 volts) per 100 ns or faster. See more amplifier videos in th-cam.com/play/PLrwXF7N522y5679YAO-lFrNVYqV9XMNTr.html op amp amplifiers videos playlist.

You are welcome. Glad that this Oscillator video is useful. Please elaborate on your question. What do you mean by applying impedances to the RC circuit below?

Glad that you are interested in this Toom3 Algorithm Tutorial video. You can find the Toom-Cook Algo Pseudocode online. In case helpful, here is a video of Toom2 aka Karatsuba Algorithm Explained with Examples th-cam.com/video/FEzBs2rrLqs/w-d-xo.html

While F=0.5 Hz is a considerably low cut-off frequency for the highpass filter, using equations explained at 18:40 , with Damping Factor set to 1/sqrt(2) we get R1=2*R2 and 2*pi*F=1/(C*sqrt(R1*R2)) . Hence we get R2 = 1/(2*pi*1.41*F*C) , if we set F=0.5 Hz and say C=1.2uF then we get R2=200 kOhm , R1=400 kOhm. Now, similarly, for lowpass filtering portion of this Sallen Key Filter, using equations explained at 26:35 , with R=100kOhm we can derive C1=11nF, C2=22nF. I hope this is helpful.

@@robr8554 You are welcome! Glad that you enjoy my videos. In case of single supply, the grounded input terminal of each op amp needs to be biased at 0.5*supply voltage. Then your output Sawtooth waveform oscillates between 0 and supply. For more Oscillator circuit videos see th-cam.com/play/PLrwXF7N522y4ee_0GL2EdguM-kLtJPxpU.html Oscillators and Signal Generators playlist. I hope this is helpful.

@@Chupacabras222 Thank you. Glad that this video is interesting and useful. Here are a few related circuit videos: Feedback Amplifier with JFET & BJT Transistors th-cam.com/video/NB1-mYglXsY/w-d-xo.html Feedback Amplifier with BJT: How to find DC Bias and AC Gain th-cam.com/video/6dLMxpLNKv4/w-d-xo.html I hope these videos are interesting as well.

Depends on your target application. In case of Audio Signal Processing, the signal frequency range is ~50 Hz to 20 kHz. So, I suggest you select your clock frequency conservatively say 400 kHz. Capacitors in the range of ~5nF to 10nF should be fine assuming switch-on resistance of NMOS transistor less than 100 Ohms (check your transistor datasheet). To be on the safe side, your NMOS switching transistors should have a max switching frequency of at least a few MHz. Lastly, given the clock frequency is not high, conservatively select a zero offset low noise CMOS Op Amp with a slew rate 20 times faster than your clock frequency. For example, if your clock rate is 400 kHz, then select Op Amp with slew rate of peak-peak (say 5 volts) per 100 ns or faster. More op amp amplifier videos are published in the th-cam.com/play/PLrwXF7N522y5679YAO-lFrNVYqV9XMNTr.html playlist. I hope this is helpful.

Thanks for watching, sharing your thoughts and asking questions. In this Band-gap voltage reference the series connection of VBE3 and R2 sets and defines the voltage drop Vdiode across the top and bottom rails of the circuits. The collector-emitter voltages (Vce) of BJT transistors T3, T4 and T5 will adjust accordingly to accommodate the forced voltage by the sum of R2.I2 and VBE3. Two related circuit videos are, Bandgap Voltage with Op Amp & Widlar Current Mirror Circuit th-cam.com/video/esMlNx5w9Jw/w-d-xo.html Voltage Regulator Design with BJT Darlington Transistors and Zener Diodes th-cam.com/video/ArisQp7V0Ac/w-d-xo.html I hope this explanation is helpful.

Thanks for watching and your follow-up question. This schematic is in a compact form (Hexagonal circuit structure) and as you noted is not the nominal straightforward (standard) way of drawing a circuit that would require a systematic flow of circuit components from left to right. The following videos are examples of third order and second order circuits with standard circuit schematic: th-cam.com/video/ENq39EesfPw/w-d-xo.html Analog Computer circuit that solves Differential Equation. th-cam.com/video/HeZRtnRXpEI/w-d-xo.html Quad Op Amps Analog Computer that solves a second order differential equation. I hope this clarification is helpful.

@@ЁбрагимИпатенкоибнАдхарма Thank you! Glad that you liked this Wilson Current Source Circuit video. Alternative design techniques are discussed in th-cam.com/play/PLrwXF7N522y48AAPxFaQlowim4-8gYoWz.html Hope this circuit playlist is interesting as well.

Glad that this op amp circuit of the Third-order Butterworth Filter Transfer Function is useful. I suggest you review your calculation of the first transfer function to make sure your derivation is correct. For more Op Amp Circuit and Analog Filter examples please see: Butterworth Analog Filter Design with Op Amp th-cam.com/video/SIMg5TOIgrA/w-d-xo.html Band-Pass Sallen-Key Filter Design th-cam.com/video/lsM09pcrRVE/w-d-xo.html Sallen-Key Filter Design Tutorial th-cam.com/video/KwUnQXbk7gM/w-d-xo.html Op Amp Analog Computer Differential Equation Solver th-cam.com/video/ENq39EesfPw/w-d-xo.html Universal Analog Filter Design th-cam.com/video/2J-0msXZE2o/w-d-xo.html Laplace Transform Example and S-domain circuit analysis: th-cam.com/video/ps8N5TPM_qU/w-d-xo.html

As explained in the video (see 25:00) by varying n (and m) we can control Damping Factor (zeta) and natural frequency (Omega) of the filter. That will allow us to control and adjust filter's response. Here are a few related examples: Laplace Transform Example and S-domain circuit analysis: th-cam.com/video/ps8N5TPM_qU/w-d-xo.html Op Amp circuit Bode Frequency plot th-cam.com/video/BLVzuuqAlZs/w-d-xo.html Bode Plot, Frequency Response, Transfer Function th-cam.com/video/vZFkPeDa1H8/w-d-xo.html Hope this explanation is helpful.

@umutaydn6184 You are very welcome. Glad that this Sallen-Key Filter Design Tutorial video is helpful. More Filter circuit videos are published in th-cam.com/play/PLrwXF7N522y7SvuzNrcDYAIwnBgC9ddjD.html Analog Filters playlist.

@@behzadabf Thank you. Glad that you liked this ECG amplifier video. Here are a few more examples, Digital Stethoscope Microphone Amplifier Explained th-cam.com/video/ez5KtkPbsHg/w-d-xo.html Thermometer Sensor Circuit Explained th-cam.com/video/5jmbZ9ak6EI/w-d-xo.html Strain Gauge Wheatstone Bridge Instrumentation Amplifier Explained th-cam.com/video/io1yBcCsP-Y/w-d-xo.html Thermometer Design with Op Amp and BJT transistor th-cam.com/video/55YsraFE0rg/w-d-xo.html Hope that these videos are interesting as well.

Thank you for sharing your thoughts on this circuit and op-amp. Please note that the op-amp's maximum allowed supply voltage is not violated in this design. The additional voltage drop across the series resistor in the supply rail will accommodate the extra voltage drop. On a separate note, there are indeed high-voltage operational amplifiers with push-pull output stages. An example is the Apex Microtechnology PA198 High Voltage Power Operational Amplifier, which delivers output voltages ranging from ±215V with a dual supply to +440V with a single supply configuration. For more information, see the APEX PA198 datasheet at this link www.mouser.com/pdfDocs/pa198u.pdf Additionally, you can find more examples of power amplifiers in the th-cam.com/play/PLrwXF7N522y4vWr-8XRBqxpi5idFDE9BV.html Power Amplifier and Voltage Regulator Video Playlist. I hope this is helpful!