Pure sinewave inverter question

Started by Daku in sci.electronics.design10 years ago 16 replies

Could some electronics guru please clarify this a bit ? A pure sine wave inverter needs to have an oscillator to produce the sine waves. So what...

Could some electronics guru please clarify this a bit ? A pure sine wave inverter needs to have an oscillator to produce the sine waves. So what type of oscillator is used typically -- Z-source inverter, or a some other type ? Any hints, suggestions would be very helpful.


(bingo!) Resolved: Apple iPhone Failures

Started by speff in sci.electronics.design3 years ago 9 replies

Following up on my rant of a few weeks ago regarding unexplained and sudden correlated iPhone "bricking", the answer turns out to be more...

Following up on my rant of a few weeks ago regarding unexplained and sudden correlated iPhone "bricking", the answer turns out to be more interesting than I would have thought possible! It turns out that Apple iPhones 6 and later and Watches use an ultra low power 32kHz MEMS oscillator. Further, it turns out that helium in the atmosphere can diffuse INTO the oscillator and cause


LC oscillator sensitivity analysis

Started by Anonymous in sci.electronics.design2 years ago 25 replies

I'm designing a 125 MHz triggered LC oscillator. It's sufficiently nonlinear that I need to Spice it in transient/time domain mode. I want...

I'm designing a 125 MHz triggered LC oscillator. It's sufficiently nonlinear that I need to Spice it in transient/time domain mode. I want to explore frequency sensitivity to component values, supply voltages, stuff like that. But how to measure frequency accurately? Cursoring one cycle of oscillation on the screen is pretty crude. I guess I could use a delay line to compare the tim...


The twisted wire oscillator and GPS jamming, a Sunday adventure

Started by Jan Panteltje in sci.electronics.design9 years ago 32 replies

The twisted wire oscillator and GPS jamming, a Sunday adventure Some time ago I found this website: ...

The twisted wire oscillator and GPS jamming, a Sunday adventure Some time ago I found this website: http://jf.fourcadier.pagesperso-orange.fr/hyperfrequences/twist/twist_e.htm He describes a Pierce type HF oscillator that uses a twisted wire as feedback... http://jf.fourcadier.pagesperso-orange.fr/hyperfrequences/twist/oscill.htm As I am making some little GHz signal generator PLL stu...


Phase Shift Oscillator Distortion

Started by David White in sci.electronics.design10 years ago 20 replies

I have been studying phase shift oscillators, and built a few up today. The circuit linked below has a slight problem I can't...

I have been studying phase shift oscillators, and built a few up today. The circuit linked below has a slight problem I can't figure out. It is intended to output 10Hz, but the tops of the sinewaves are slightly skewed to the left, and there is a "kink" as they approach 0 volts before progressing to the next cycle. http://www.4shared.com/photo/mtkJplbI/Phase-Shift-Oscillator.html? ...


Screw Up

Started by garyr in sci.electronics.design9 years ago 3 replies

I'm trying to build a DDS VFO I've designed. Today I started adding parts to the board, first the voltage regulator. Voltage OK, 3.301 volts....

I'm trying to build a DDS VFO I've designed. Today I started adding parts to the board, first the voltage regulator. Voltage OK, 3.301 volts. Then I added a 50 MHz oscillator (CTS CB3LV); 3.3 volt line now measures 1 volt. Poking around a bit I find that the VCC and ground going to the oscillator chip are swapped (the pin numbers I assigned to the package drawing I created were incorrect). I ...


Parametric Oscillator, Featuring: Space Itself

Started by Tim Williams in sci.electronics.design5 years ago

...Sort of. At least, that's kind of how I choose to interpret it: https://phys.org/news/2017-01-quantum-vacuum-traffic-space.html Being in...

...Sort of. At least, that's kind of how I choose to interpret it: https://phys.org/news/2017-01-quantum-vacuum-traffic-space.html Being in pulsed mode, it's not really fair to call it a parametric oscillator, but the "squeezing" description seems reasonable enough. Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventrans...


How do you determine phase noise for this circuit?

Started by RobertMacy in sci.electronics.design7 years ago

The following is a simple [absolutely made up, stupid topology, but simulation predicts it oscillates] RC oscillator that seems to want to run ...

The following is a simple [absolutely made up, stupid topology, but simulation predicts it oscillates] RC oscillator that seems to want to run slightly under 400Hz. Because it is an RC oscillator, how does one determine the phase noise, or jitter, or however one specs this thing by using LTspice? I used a simple .tranoise model and it shows/predicts in a spectral plot the sideban...


200kHz oscillator

Started by Piotr Wyderski in sci.electronics.design5 years ago 11 replies

I would like to experiment a bit with magnetic parametric amplifiers. For that purpose, I believe I need a 200kHz sine wave generator with a...

I would like to experiment a bit with magnetic parametric amplifiers. For that purpose, I believe I need a 200kHz sine wave generator with a watt worth of output power. My obvious choice was to construct a current-fed resonant Royer oscillator. For a 1nF tank capacitor it implies a 633uH inductor (2x5 turns on a 6400nH/turn^2 way to big toroidal core), 2x ZTX851, a 100k base polarization resi...


Mini Tesla Coil design

Started by bitrex in sci.electronics.design4 years ago 3 replies

I was daydreaming about building a miniature Tesla coil at some point as a weekend project. Like an 8-10" secondary with 500-700 turns of 28...

I was daydreaming about building a miniature Tesla coil at some point as a weekend project. Like an 8-10" secondary with 500-700 turns of 28 gauge magnet wire, maybe. I thought it also might be fun to make it a hybrid design, using lil power triodes or tetrodes for primary drive, driven from an xtal oscillator or SPI-controllable oscillator like the DS1077. I'd imagine having a bifil...


Help Given phase noise in a source, what is the effect?

Started by RobertMacy in sci.electronics.design7 years ago 62 replies

How do you do this... Given a 1kHz oscillator that has 1 degree rms of gaussian phase noise, what is the effect? For example, if I put...

How do you do this... Given a 1kHz oscillator that has 1 degree rms of gaussian phase noise, what is the effect? For example, if I put the oscillator's output into a spectrum analyzer, what should the spectrum look like? or, into a DSP FFT spectrum analyzer? Quantified amounts please. I got NO answer on the question I posted last Saturday regarding an LT1115 circuit, so see if...


Null fundamental of tuning-fork crystal

Started by bitrex in sci.electronics.design5 years ago 30 replies

Is it possible to add something to the Colpitts oscillator topology to null the fundamental of a standard 32.768 kHz "tuning fork" crystal, and...

Is it possible to add something to the Colpitts oscillator topology to null the fundamental of a standard 32.768 kHz "tuning fork" crystal, and run the oscillator at the crystal's next highest mode (191kHz?)


Relaxation Oscillator as a perfect example of regenerative feedback

Started by Patrick Chung in sci.electronics.design7 years ago

Relaxation Oscillator circuit is a perfect example of regenerative feedback that is special case of positive feedback. Simple and efficient, this...

Relaxation Oscillator circuit is a perfect example of regenerative feedback that is special case of positive feedback. Simple and efficient, this circuit is practical for students labs and still applicable in the blinking turn signal on motor vehicles, use in stroboscopes and as the time base in early oscilloscopes and television receivers. Read more: http://www.cirvirlab.com/in


Colpitts crystal oscillator in LTSPICE

Started by bitrex in sci.electronics.design6 years ago 59 replies

I'm trying to simulate a low frequency Colpitts oscillator in LTSpice using an NPN darlington and a crystal, and I'm having a lot of trouble...

I'm trying to simulate a low frequency Colpitts oscillator in LTSpice using an NPN darlington and a crystal, and I'm having a lot of trouble getting it to start up. Does anyone have a working one of these? I'm just using a capacitor to simulate the crystal, the parameters I am working with are something like: motional capacitance: 5.3ff ESR = 11k ESI ~ 4500 henries EPR = 100 meg E...


Bandaxall Oscillator

Started by Kooner in sci.electronics.design10 years ago 15 replies

Hello, I made a Bandaxall Class D Oscillator with a 11mm x 7mm pot core transformer and it works quite well. The input is 8VDC and...

Hello, I made a Bandaxall Class D Oscillator with a 11mm x 7mm pot core transformer and it works quite well. The input is 8VDC and the secondary output is 800V peak to peak. The transformer is very difficult (for me) to wind because the secondary uses #46 awg wire and it breaks easily. Also, I would like to use a shorter transformer, around 5mm tall. There are smaller pot cores but ther...


Next: The tunnel diode oscillator.

Started by Jan Panteltje in sci.electronics.design8 years ago 33 replies

Next: The tunnel diode oscillator. Given an LC wit some Q (read damping), if we can neutralize that R, would it start swinging all by...

Next: The tunnel diode oscillator. Given an LC wit some Q (read damping), if we can neutralize that R, would it start swinging all by itself? Well how do you neutralize a resistor? Simple: put a negative resistor in series or parallel with it. Mr Esaki invented the tunnel diode many years ago, it has, at some point, a negative slope in its I versus U curve. So use a properly biased...


Baxandall class-D oscillator squegging and the VBIC model

Started by Bill Sloman in sci.electronics.design10 years ago 31 replies

The Baxandall parallel class-D oscillator "squegs" in real life if you build it with a high value inductance in the current feed and...

The Baxandall parallel class-D oscillator "squegs" in real life if you build it with a high value inductance in the current feed and bipolar switches. An LTSpice circuit using the Gummel-Poon model for the bipolar transistors doesn't show this - it settles down to a stable sinusoidal oscillation within less than a hundred cycles. The obvious effect of using a high value inductor is that the...


Frequency synthesis, all-digital type

Started by whit3rd in sci.electronics.design8 years ago 1 reply

In addition to (AD9838 style) things with DAC outputs, there are PLL solutions to the make-me-a-frequency-to-order problem. Basically, start...

In addition to (AD9838 style) things with DAC outputs, there are PLL solutions to the make-me-a-frequency-to-order problem. Basically, start with a reference oscillator (F_ref) and divide it by a counter-based logic (which gets F_ref / N_one), and phase-lock to a voltage-controlled oscillator F_vco, with its own divider F_ref/N_one = F_vco/N_two There are reasons to prefer that both N_o...


SPICE tarnsient analysis of oscillators - sampling time

Started by Anonymous in sci.electronics.design3 years ago 43 replies

Could some electronics guru here please clarify this a bit ? I am experimenting with SPICE transient analysis of oscillator, and I am unsure as...

Could some electronics guru here please clarify this a bit ? I am experimenting with SPICE transient analysis of oscillator, and I am unsure as to what to set as the ideal sampling time, given that most oscillators will generate a fundamental and a few harmonics. For example, suppose that I have a 500 MHz differential oscillator, and I set the sampling time as 1/(15.0*time period of fund...


Ramp Type Oscillator with Bottom Release

Started by Jim Thompson in sci.electronics.design4 years ago 43 replies

Ramp Type Oscillator with Bottom Release In the past I did this (in bipolar), so that I got a near-zero release of the "dump" function by...

Ramp Type Oscillator with Bottom Release In the past I did this (in bipolar), so that I got a near-zero release of the "dump" function by sensing saturation... ... easy with bipolar devices. Any ideas on how to do it similarly with CMOS? (Comparators sensing near zero are risky with CMOS due to crappy offse