LC oscillator sensitivity analysis

Started by Anonymous in sci.electronics.design3 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...


BJT behaviour at ridiculously low current levels

Started by Piotr Wyderski in sci.electronics.design6 months ago 72 replies

Hi, I am experimenting with ultra-low power ideas and I was able to simulate a 30Hz relaxation oscillator running at 45nA/1V. I am waiting...

Hi, I am experimenting with ultra-low power ideas and I was able to simulate a 30Hz relaxation oscillator running at 45nA/1V. I am waiting for the delivery of high-value resistors, but the same oscillator with resistors scaled down 10x works on the bench and consumes ~380nA/3V/360Hz which is still pretty awesome. This real device has been made of BSS123/BSS84 operating in the subth...


200kHz oscillator

Started by Piotr Wyderski in sci.electronics.design6 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...


Colpitts crystal oscillator in LTSPICE

Started by bitrex in sci.electronics.design7 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.design11 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.design9 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.design11 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...


SPICE tarnsient analysis of oscillators - sampling time

Started by Anonymous in sci.electronics.design4 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...


Efratom rubidium oscillator manual

Started by John Larkin in sci.electronics.design12 years ago 10 replies

ftp://jjlarkin.lmi.net/Efratom.pdf

ftp://jjlarkin.lmi.net/Efratom.pdf


Trying to remember IC name

Started by bitrex in sci.electronics.design9 years ago 11 replies

I'm trying to remember the name of a certain IC. I believe it was a PLL-type frequency synthesizer IC for AM/FM radios, to be used with an...

I'm trying to remember the name of a certain IC. I believe it was a PLL-type frequency synthesizer IC for AM/FM radios, to be used with an external local oscillator. I'm fairly certain it had the prefix SA-something, so it was a former Signetics chip. I don't think it's still in production by NXP, though. Any ideas?


eclips oscillator

Started by Anonymous in sci.electronics.design10 months ago 12 replies

https://www.dropbox.com/s/627ifxuw3rsexj2/EP11_Oscillator.jpg?raw=1 Wonder how that will work. I'll have one of my people try it. It would...

https://www.dropbox.com/s/627ifxuw3rsexj2/EP11_Oscillator.jpg?raw=1 Wonder how that will work. I'll have one of my people try it. It would certainly work with a fast comparator with hysteresis. -- I yam what I yam - Popeye


Royer oscillator - phasing dots

Started by John S in sci.electronics.design2 years ago 19 replies

https://en.wikipedia.org/wiki/File:Royer_oscillator.gif I think the transformer phasing dots are wrong. Or, am I wrong?

https://en.wikipedia.org/wiki/File:Royer_oscillator.gif I think the transformer phasing dots are wrong. Or, am I wrong?


are all the function generators gone?

Started by John Larkin in sci.electronics.design10 years ago 65 replies

I'm being asked to make some replacement FSK modems for a system I designed about 30 years ago... not much money to be made, really just a...

I'm being asked to make some replacement FSK modems for a system I designed about 30 years ago... not much money to be made, really just a charity job. I originally used the XR2206 as the transmit oscillator, and they are gone. Well, Mouser has one piece for $83. MAX038 is gone, too. Jameco has some 2206 DIPs, which I could scoop up, I guess. Anybody know of a classic analog sinewave gen...


The tunnel diode is back, as TeraHertz oscillator

Started by Jan Panteltje in sci.electronics.design11 months ago 11 replies

Terahertz radiation source: Compact and simple: https://www.sciencedaily.com/releases/2022/01/220111112018.htm paper: ...

Terahertz radiation source: Compact and simple: https://www.sciencedaily.com/releases/2022/01/220111112018.htm paper: https://aip.scitation.org/doi/10.1063/5.0068114 Interesting on chip construction


74HC74 oscillator simulation

Started by bitrex in sci.electronics.design3 years ago 36 replies

IRL I don't think there's anything this configuration of the 'HC74 could do but oscillate; with an RC network from not-Q to not-CLR and D, CLK,...

IRL I don't think there's anything this configuration of the 'HC74 could do but oscillate; with an RC network from not-Q to not-CLR and D, CLK, and not-PRE grounded. But with these models from the Yahoo LTSpice users group the LTSPice time domain looks like it manages to find some other metastable state and sits there spinning its wheels. Can anyone suggest some ICs that could bust i...


Learning about oscillators in LTSpice

Started by Clifford Heath in sci.electronics.design8 years ago 68 replies

I'm just getting started with LTSpice, and played yesterday with some Colpitts oscillators to my satisfaction. Today I tried a Hartley, and I...

I'm just getting started with LTSpice, and played yesterday with some Colpitts oscillators to my satisfaction. Today I tried a Hartley, and I can't understand some of the behaviour I'm seeing. In the attached circuit, I've added an emitter resister in an attempt to reduce the high collector current. Merely increasing the base resistor didn't help until the oscillator stopped entirely. Act...


200MHz VFO

Started by George Herold in sci.electronics.design9 years ago 29 replies

Hi guys, The 200 MHz. frequency synthesizer thread got me thinking. I could use a 200MHz VFO (say 150 to 250 MHz or something like that) I...

Hi guys, The 200 MHz. frequency synthesizer thread got me thinking. I could use a 200MHz VFO (say 150 to 250 MHz or something like that) I don't need much stability, a part per thousand for a several minutes would be enough. So what's the simplest way to get there? An LC oscillator (I've got some nice tunable few pF caps) There's also a VCO from Maxim. (max2607) that looks easy. http://...


SPICE gets it wrong

Started by Tim Williams in sci.electronics.design6 years ago 74 replies

Speaking of SPICE, here's a nice little circuit: https://www.seventransistorlabs.com/Images/BakerDarlington.png I discovered the oscillator on...

Speaking of SPICE, here's a nice little circuit: https://www.seventransistorlabs.com/Images/BakerDarlington.png I discovered the oscillator on the left, when attempting to build a Darlington transistor pair with a Baker clamp. (In practice, R10 comes from a logic voltage input, and R2 is a load, often inductive. R14 is optional, but exacerbates the oscillation, making it reproducible.)...


Capacitance value for PIC crystal

Started by P E Schoen in sci.electronics.design9 years ago 41 replies

For most of my projects I use either a 14.7456 MHz crystal (57600*256) = or=20 20.000 MHz (for USB 96 MHz 24*f/5). The 20 MHz crystal I am using...

For most of my projects I use either a 14.7456 MHz crystal (57600*256) = or=20 20.000 MHz (for USB 96 MHz 24*f/5). The 20 MHz crystal I am using = specifies=20 a 20 pF parallel load, but my boards have 12 pF capacitors. I just = noticed=20 this and I think the value had been selected for a previous brand of=20 crystal, but the oscillator frequencies measure pretty close to the = ideal=20 ...