5 Ways To Generate A Sine Wave (Analog)

Comments · 246

• JU

  @justovision · 2 years ago

  Side note: Using a light bulb to create a stable sine generator was the idea behind Hewlett Packard's first product and they continued manufacturing them in basically the same form into the 70s. I have a 201c from the early 70s on my shelf that still works well.

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• JY

  @jyoutishmanroychoudhury3324 · 2 years ago

  Learned all this in my bachelor's in Electrical Engineering, which was mostly from a theoretical a numerical point of view, but after watching the applications of it and the simple explanation gave a clear understanding of it. Thanks for making this video, keep up the good work!

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• IN

  @InssiAjaton · 2 years ago

  A little note about the original pronounciation of Mr. Wien’s name.  It was not “wine”.  Maybe closer to English spelling would result from “ween”.  Probably useless to try making any change, considering that the name of the city — Wien — is in English world also modified to Vienna…  Just my today’s rattle!

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• YO

  @yottakm3764 · 2 years ago

  I needed a Sine wave to go threw me so I plugged my self into the wall

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• DR

  @drgazter · 2 years ago (edited)

  Please make a video about “negative resistance devices”.<br>You can theoretically make a sine oscillator with just a LC tank circuit and a tunnel diode.<br>Another device that can work is called a “lambda diode”. It’s basically either two JFETs or a JFET/BJT pair that has a I/V curve looking like a capital lambda symbol.<br><br>Speaking of other sine wave generator designs:<br>1.) Triple inverter hysteresis oscillator making a triangle wave over a capacitor followed by an integrator opamp active filter.<br>2.) Emitter-Coupled LC Oscillator, which is harder to explain but it’s basically an attenuated LC tank hooked to an “anti-current mirror” differential amp setup made from two NPN BJTs. Since the common emitter pointing in a constant current sink thing makes the opposite BJT do the opposite thing compared to the BJT in which we feed the LC signal, it acts to increase the oscillation with each swing. However, due to the current limiting element and due to dampening, the oscillation stays a clean sine wave. Furthermore, this oscillator is more exact than the Colpitts or the Hartley variants because it only uses one inductive element and one capacitive element. With like 3 resistors, 2 BJTs, an L and a C, this is one of the simplest oscillator designs besides the tunel diode oscillators.<br>3.) Double active integrator filter inverter loop. Very similar to phase locked loops except you have an active non-inverting proportional-integrator-derivative filter in series with an active integrator filter. It has 3 resistors, 3 identical capacitors and 3 opamps. One of the resistors on the derivative side of the pid needs to be a few ohms lower than the rest (for stability and to avoid saturation).<br>4.) Emitter-Coupled Crystal oscillator (yep, there are those too). Same as the one above but the LC + R is replaced with a crystal.

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• FO

  @foureyedchick · 4 months ago

  I got an idea: Make a 6Mhz crystal oscillator with a 6Mhz crystal. Pump it through 5 7490 decade counters in series. Go from 6,000,000 to 600,000 to 60,000 to 6,000 to 600 to 60 Hz.Filter the 60Hz square wave into a sine wave with an LC filter. Amplify the HELL out of the tiny sine wave with a car subwoofer amp. Hook up a transformer at the speaker terminals. Connect an outlet to the output of the transformer through &nbsp;a fuse. You got a low-drift UPS for your computers, TVs, etc.

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• WE

  @wernerfritsch6436 · 2 years ago

  A common way to generate a sine wave used in analog function generators is to generate a triangular wave by switching a current source on a capacitor and then distort the triangular wave to a sine wave with a ladder of diodes and resistors. The THD is not that good (typ. 0.5%), &nbsp;but it is easy to vary the frequency.

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• DA

  @dalenassar9152 · 2 years ago

  GREAT VIDEO!<br><br>I once made a &quot;variable&quot; sine wave oscillator with a switched-capacitor filter IC. &nbsp;With this filter chip (the mf-10) the output center frequency is determined by a square-wave input. &nbsp;I just varied the square-wave input (10x the output filtered frequency), and got a completly variable sine out, just by varing the input of a 555 timer. &nbsp;This allowed the the output sine frequency and amplitude to be independently varied with an op-amp at the output.<br>thanks again for the video!!

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• JA

  @jagmarc · 2 years ago

  I&apos;ve done every one of these in past when I was a designer. &nbsp;There&apos;s quite a few things can do with each circuit that makes the sine purer and output level more stable, but most real applications don&apos;t need them. &nbsp;The JFET agc is temperature sensitive output level, can get two orders more stability by using a bandgap reference plus long tail pair

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• VI

  @ViniciusMiguel1988 · 2 years ago

  I wish you had compared phase noise and total harmonic distortion between all of them , because is the most important factors if you need a sine wave oscillator

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• NE

  @Neverforget71324 · 2 years ago (edited)

  <a href="https://www.youtube.com/watch?v=EhMk6DUbbPk&amp;t=489">8:09</a> My home made sine wave generator uses the Wein bridge configuration with a full wave rectifier to control the JFET... it can generate Sine waves from 1.5 Hz up to about 130KHz and has a ridiculously low distortion (less than 0.05% between 1.5 and 20KHz and about 0.1% above that. So, it definitely is possible to make this work.

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• JA

  @jamesmorton7881 · 2 years ago

  Where is the twin Tee notch ? &nbsp;It provides very &nbsp;low distortion, &nbsp;stability, and simplicity using an OPAMP. &nbsp;Very good presentation. &nbsp;<br>Check out Analog Devices DDS (direct digital synthesis) for the ultimate in range. &nbsp;Programmed with SPI or I2C. &nbsp;Follow it up with a multiplying DAC for amplitude control.

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