# Self Oscillator Circuit

292 Threads found on edaboard.com: Self Oscillator Circuit

Dear Boy, When I talk about open loop analysis, I am talking about to cascade the active device itself with the resonator is being used in the oscillator. To properly open the loop you have to identify, looking at the oscillator topology you are using, what element is coupling signal to the input of the active device. For example regard (...)

## Self-Oscillating Mixer Simulation

Anyone can help with the above problem? Pls? Also, in HB sim, non-linear models for FETs & BJTs are to be used. So when a feedback is required to make the active device unstable, should I use the linear (small-sig) model or the non-linear one (which will be the one eventually used in HB sim)??? Thanks in advance To s

## faster oscillator turn-on time

I wonder if it will be possible to switch in another loading element for a very short period to lower the overall Q of the resonator to speed up starting. I never tried this myself. It should be interesting to investigate with the aid of a simulator. Also oscillations can only start when the active biased region for the transistor is established. T

## how to produce 21 volts from 3.6V

One option is discussed by kender, which is a boost converter. Other option is the self oscillator circuit, in which a small transformer (ofcourse ferrite) is self oscillated with one or two windings and produces a square wave stream, which can be rectified and regulated.

## BJT for the lowest phase noise XTAL oscillator

rfmw that's interesting. With wich topology do you reach such a low wideband noise floor? In one design I came across one day using BFR93 it was only -150dBc/Hz, and that is typical. Another topic I'd like to hear from you guys is FM noise from the crystal. I was trying to find out why we could not reach our spec @ 10/100 Hz offset, and I read t

## Who Start the Oscillator into Oscillation the First Time?

If I talk about Hartley,Collpit oscillator,square wave general, it's said feedback must be positive,in phase and the close loop gain must be greater than 1 and there are various feedbacks also in shape of current-series/shunt,voltage series-shunt.Also in some oscillator no input signal is needed to start the oscillator going.Only cond

## high output power colpitts oscillator

... because there is a relation between the wavelength and the radius of the aperture (coil) as in optics and antenna optics, ... Hi, Its relative unusual to make a coil with extreme high parasitic capacitances-but not inpossible. I see the bigger problem on the secondary site/load coil, then it will maybe mobile and so are

## Self Designed RF Circuit Tx Problems

Actually, I don't think that will work at all. L1 is DC shorting the base and collector, The combined inductance of L2 and L3 depends on their separation and orientation, The total possible DC current is restricted to 0.5mA by R1, Even if R1 was moved to a more sensible position between L1 and R2, the emitter current is still limited t

## Self biased ring oscillator question

Hi Guys, I am trying to design a symmetrical load ring oscillator using the self biasing circuit shown in the maneatis paper. Attached is a schematic showing the self bias circuit. My question is, it shows an OPAMP. How do I design this? Do I have to design each individual stage of the opamp (buffer + (...)

## Why this oscillator does not work?

Zeller, It is a petty not to see your oscillator's display. I have simulated it (using Micro Cap) and it seems to work properly. Nevertheless, the following items have to be considered: 1) The output oscillation range is no more than 2Vpp, taken at the COLLECTOR. This low range is due to the high value of R3, whi

## Crystal square wave oscillator discrete components

You're likely going to be stuck with a sine wave core, and gain it up until it clips and looks digital. And it's not true that you need to use discretes. Look how long things like CD4000 logic have been around. And it doesn't look like they're going anywhere. In fact some of the "unbuffered inverter" gates are useful for this sort of thin

## Need a short beep circuit

My apologies, I prefer the first option, with the volume fading after the 1 second tone. It can be a fairly quick fade, too. Just something to smooth out the end of it. You will be able to select the timing yourself by changing C * and/or R. My wall wart outputs 12v, so I can use that for the amplifier

## Bubba Oscillator and THD

Quote: Do you mean that the first OP in loop or the separate gain controller in my circuit? What is the "first" OP in a closed loop? Sorry for this unnecessary comment. As I`ve mentioned, it is the gain-of-four amplifier that suffers from clipping (always the amplifier with the highest gain in the loop). But - as shown in your diagram - it i

## Self-Oscillation Schmitt Trigger

I have a question about self-oscillation schmitt trigger frequency? Can I get 10 MHz square wave from self-oscillation schmitt trigger. I build up schematic that is given below. Also, I must use LM158. Anyone can give me an idea if it is possible to

## How does LC phase shift oscillator work?

That necessary condition that makes that a linear system becomes a quasi-sinusoidal oscillator (i.e. Phase vs. frequency must have negative slope) is frequently overlooked. Let's try an intuitive, non rigorous justification: Imagine a linear circuit with an input and an output. Supose thet we connect a sinusoidal generator at the input

## Variable frequency sinusoidal wave oscillator

I wonder, if there are additional specifications besides frequency range and voltage range. Strictly spoken, the latter isn't a matter of oscillator design rather than using a reasonable amplifier. For the oscillator itself, you'll need to think about waveform quality respectively distortion, frequency accuracy, amplitude constancy, method (...)

## Class C Power oscillator design

Hello Goldsmith, I think the best you can do is try to understand how the various DC to AC topologies function. Also check how they behave under your load (inclusive load variations if present). Application notes may be helpful in mastering DC to AC conversion. "Solid state radio engineering" also has a chapter on efficient RF power amplifier

## Low level AM Transmitter Circuit and little description.

My teacher is strictly forbidden to use crystal oscillator. So if I asked for it from market then it is of no use for me. I don't know what is your teacher's reas reason , but no problem , you can use this circuit as your oscillator stage , easily , see below , please :

## Understanding Crystal Oscillator

First of all, let me state that I have very little understanding of electronics, as I just started self-learning not too long ago. So, I thought that it will be a good way to learn electronics by working on fun projects. Thus, I have decided to make a digital clock using a crystal oscillator. . Are you really

## Question: Component selection for a stable Local Oscillator

If your circuit is a parallel circuit , to increase the Q factor , decrease L value and increase the C value to maintain the resonance frequency. Another solution , in a a parallel resonance circuit there two resonance point. One of them comes from parasitic capacitance of the coil and self inductance of the coil and (...)

## Self Defense Stun Gun circuit

Hi all This stun gun circuit any one have other circuit like this :evil: S 8O KRAT

This is an official HP document from 1998. It appears to be part of a class or a self study course.

## How to make Small X-Band Oscillator

Try Agilent App Note A008 too. Also, I need some help: I need to design a self-oscillating mixer (SOM) at 2.4GHz. A DR is coupled to 2 microstrips connected to gate and drain of FET forming the feedback like in many DRO designs. 2 questions... 1. How do i model a DR coupled to 2 microstrips? (Technical papers show that they did it, but not

## What is the difference between a crystal and an oscillator

As others above have explained, an oscillator is a self-contained module that outputs a square wave at the desired frequency. A crystal needs a surrounding circuit to be useful, typically for PICs, a Pierce circuit with neighboring capacitors going to ground. An oscillator is more expensive and draws (...)

## Symmetrical Load Ring Oscillator Design

Yea I have implemented the self-biased ckt. I am trying to meet the spec of Δf/ΔVdd<1%. How much variation in Vdd should I design up to? I am using 2.8 V supply voltage in TSMC 0.18 process. Thanks

## Oscillators using Op. Amp. How they start to oscillate ?

in order to generaste self oscillating on opamp circuit yuo must put opamp in feedback mode (some kind like that idon't know the term) and the feedback gain should have -1 magnitude in order to make positive feedback so if there is little bust voltage either from change at power supply or noise spike (maybe) could generate voltage on opamp output

## oscillator design and pcb

I hope this will help: 1.) U cant use cond2 as bottom ground plane, cond and cond2 are metalization layers of the top plane as far as I know. GRND is regarded as a close boundary in Layout. 2.) Use Via2 (round Via) from the TLines-Microstrip Menu to connect the pin to the ground plane. Set diamaterer for your hole and just export your d

## How to eliminate self-oscillating from a Colpitts oscillator?

I design a Colpitts oscillator f=2GHz.But the output is 500MHz and its this self oscillating?how to eliminate it?

## Help me design a self-excited BJT mixer in ADS

Assalamo Alaykom I want if anyone help me to design a selfexcited mixer ( BJT Mixer ) in general circuit and using ADS tool .. I just want this as a training to the ADS software .. Thank you very much ..

## research idea in rf circuit design

Allright, here is one concept. Modern military aircraft achieve great agility by operating in the unstable region of flight. That is, if there were not some very fast control loops keeping the plane flying properly, the pilot would not be able to pilot it for more than a few seconds before it augered in. In the old days, when vacuum tubes were

## Oscillator Design and Computer Simulation

oscillator Design and Computer Simulation Randall W. Rhea This book covers the design of L-C, transmission line, quartz crystal and SAW oscillators. The unified approach presented can be used with a wide range of active devices and resonator types. Valuable to experienced engineers and those new to oscillator design. Topics include: (...)

## Will a CMOS inverter work as an Amplifier?

of course you can. 1. such as two stage opa, the last stage can be an inveter 2. use self-biased, you can use the inverter as an opa

## Problems with Colpitts oscillator

Hi... i think knowing the reason for which your simulation don't start!!! Obviously we start from the point that the circuit gets the Barkausen conditions.... u should verify these conditions opening the loop in a good point and verify that they are fulfilled. Then u must put a time varying discontinue in your circuits... for example u put a p

## a problem about divided by two circuit!

Commercial could mean more user friendly but possible more power consuming. That is because the highest sensitivity and lowest power is where the divider operate as injection locked oscillator. I think you have the lowest required power level for correct operation where the selfoscillation is. If selfoscillation should be blocked you (...)

## Induction heating- using MOSFETS

I am not sure if you have come across this site but I think you will find a lot of interesting info on induction heating .. A conceptual MOSFET self resonant oscillator This design is a result of small scale experimentation. I originally wanted to use SCRs because of the simplicity of the design. But it turns out that low cost, readily ava

## How these circuits work? (AM transmitter and receiver)

The right-hand transistor in the oscillator circuit is supposed to be an oscillator. It is meant to make a carrier signal by itself. The transmitter input is a microphone. It is intended for audio frequency signals around 300Hz to 5KHz. An AM radio link can only carry signals at much less than the carrier frequency. (...)

## I want to build a Mixer.. Hope the oscillator is built in

You might try a dual gate fet mixer at this frequency. THere is a zip file in this link. It is very useful. For self oscilating dual fet mixer It is a US patent

## Clock Duty Cycle Correction Circuit

hi Sachin, I once read two papers about clock duty cycle cerrection, one is G J.Maneatis, "Low jitter process-independant DLL and PLL based on self-biased techniques", JSSC VOL.31.NO11,1996. the other is J.Lee," A low-noise fast-lock phase-lock phase-locked loop with adaptive bandwidth control,JSSC VOL35.NO8,2000. hope this will help. EN

## Frequency Generator/Oscillator

Kindly share u'r ideas, suggestions and experience in self building and experimenting a 100 Mhz frequency generator. Is it possible to make it work accurately without using any specialized soldering technique etc.?

## How is quenching circuit used in superregenarative receiver?

Well, superregen is a strange beast indeed. Lets say you had a transistor that had 20 dB of gain at your RF frequency of interest. It will boost up a weak signal by 20 dB, nothing more, nothing less, if it is used as a linear amplifier. However, if you set up that same transistor with positive feedback, it will, for a brief period of time, hav

## Analog Delay locked loop circuit THESIS

CMOS DLL-based 2-V 3.2-ps jitter 1-GHz clock synthesizer and temperature-compensated tunable oscillator Foley, D.J. Flynn, M.P. Dept. of Microelectron, Nat. Univ. of Ireland, Cork, Ireland; This paper appears in: Solid-State circuits, IEEE Journal of Publication Date: March 2001 Volume: 36 , Issue: 3 On page(s): 417 - 423 Meetin

## Help: 32K oscillator startup problem

you simply need a 10uh choke and a decoupling cap on the vdd rail to the buffer and amp stages replace the 10k resistor with a paxilon peg and wind 10 T .28mm dia ecw 1.2mm dia the rf is using the resistor as a coil and this has the effect of a dampener on the system as the rf leek away haphazardly finaly clamp it with a zener at +5.1v before the

## Source for PLL input frequency

the crystal it self is not an oscillator , so u can't connect it to the input of the PLL , u need a crystal oscillator to use crystall as the resonator , and the output of the crystal oscillator will be the input of the PLL khouly

## What is the function of parallel RC circuit?

R provides control to the rate of charging and discharging, without resistance, the capacitor will charge &/or discharge instantaneously, R limits the current, thereby allowing the charging and discharging to happen gradually, governed by: Vch=V(1-e^(-t/τ)) Vdch=V(e^(-t/τ)) Where V=system/total/ supply voltage t= ti

## Problem with Clapp oscillator

the oscillator don't want to oscillate :cry: I removed the 8M and tryed another bf245c, choke of 1.9mH nothing. the inductor is a iron core self (transformer hf type)

## Intelligent battery charger circuit

hi, I have a litte different problem. Suppose, I have a charger to charge optimaly according to my need, and suppose that I have an apropriate source of power, via AC-DC adapter, to drive my intended load (led, motor, whtever). I want to have a system which should run normaly from power source (AC-DC adapter) and want to have the battery

## Need help! Regarding an oscillator output circuit design..

I'm designing a 2 legged robot, which will be able to move backward when bumping into an object. But now i only concern how to change from moving forward to backward, by triggering the changes my self, no need bumping into an object. Still testing. Can anyone give me some ideas? I'm really stuck here.

## Electromagnetic interference on PIC16F877A?

Yeah I know the last post stated to use the caps, but, for some reason the original poster refuses to use the caps because he thinks they are for no reason.... I strongly recomend to use the 22pF caps! you are dealing with data communications that require some what accurate timing... If you have a pic running an Xtal with no caps, the timing would

## What is a neon lamp doing in electronic circuit?

Hello, would be much easier, if we would know the said board's purpose (if known at all)... If the part is cylindrical with axial wires, than it's probably a surge arrestor or switching sparg-gap. This is actually the same device, but for different applications. Together with the said resistor and capacitor, it forms a very simp

## Which pin of EEPROM should be connected to pumping clock of charge pump?

So, the charge pump circuit must have self-osillator circuit??