285 Threads found on edaboard.com: Oscillating
.....But from my circuit i think that pull up resistor (at output of opamp) make the output 4V while inputs are not given. Am I right ??
no. The comparator has an input offset voltage that could be positive, negative or zero so the output could be high or low or oscillating.
Analog Circuit Design :: 12-03-2014 16:52 :: Audioguru :: Replies: 5 :: Views: 1957
This are two cascaded first order filters which have real poles and can't show an oscillating step response by nature. Instead you'll want a second order filter with a complex pole pair. It can be implemented either as LC filter or as active filter with feedback. Some references are here
Analog Circuit Design :: 11-01-2014 09:40 :: FvM :: Replies: 5 :: Views: 1412
All amplifers will contain contain noise in the bandwidth of the oscillator and even overtones of crystal oscillators. The harmonic with the highest gain will end up oscillating.
Both input transients on power up and random noise contribute signal that gets filtered. In the case of a balanced oscillator with exactly unity loop gain at 0 or 360 de
Elementary Electronic Questions :: 09-16-2014 21:45 :: SunnySkyguy :: Replies: 13 :: Views: 795
LNA is showing same output what ever the input it has, it is not showing amplifying signal. Some LNA is showing negative gain, when -500mV appeared at the gate.
I think your LNA is oscillating, at a frequency that you are not looking for...
RF, Microwave, Antennas and Optics :: 09-13-2014 14:54 :: vfone :: Replies: 32 :: Views: 2740
I have here a simulation (LTspice) of a self oscillating Buck LED driver. It just regulates the LED current by switching ON/OFF its FET when the inductor current hits the requisite peak and trough levels. One comparator acts on the peak of the inductor current, the other, on the trough. (there is a resistive inductor current sensor)
Power Electronics :: 07-06-2014 10:24 :: treez :: Replies: 8 :: Views: 924
I answered this for you in the other forum......
AN oscillating electric field creates AN oscillating magnetic field
my bold added for clarity
Yes that is correct ... but it goes further
an oscillating electric field creates an oscillating magnetic field, which creates an oscillating electric (...)
RF, Microwave, Antennas and Optics :: 06-19-2014 12:02 :: davenn :: Replies: 3 :: Views: 959
Your simple buck regulators may be oscillating with insufficient load capacitance and low ESR for ripple or simply insufficient pre-load of 10% before the switch.
Please advise if adding preload helps on stability and larger low ESR Cout Caps.
- - - Updated - - -
Your simple buck regulators may be oscilla
Power Electronics :: 06-04-2014 13:59 :: SunnySkyguy :: Replies: 5 :: Views: 1080
If you want a -regulated- high voltage output then you need
all of the functionality of these integrated PWM regulators.
If you need only rough, much higher voltage then simpler
self-oscillating boosters could do. To make one of these
have good regulation, especially dynamic and with safety
features, would end up being more elaborate (to the board
Analog Circuit Design :: 04-25-2014 20:09 :: dick_freebird :: Replies: 17 :: Views: 4081
I have just constructed the truxgraphics power supply but it just wont stop oscillating and it is gives a maximum voltage within 1v of the preset maximum CAN SOMEONE HELP
Microcontrollers :: 04-17-2014 17:42 :: m.ngoni :: Replies: 0 :: Views: 681
What do you see at the terminals when it stops working?
Extremely long leads can bring you oscillation problems,
consider the 3-wire bundle as a lousy tank and feedback.
Just to pull decent DC curves from high frequency transistors
on a ~10cm wire length fixture often required ferrite beads
to keep the thing from oscillating. At 10 meters, bet on
Analog Integrated Circuit (IC) Design, Layout and Fabrication :: 04-05-2014 02:44 :: dick_freebird :: Replies: 3 :: Views: 679
I've got a a circuit with three cascaded LNAs (MGA-62563) and there is a lot of oscillation. I depopulated a LNA stage to simplify the problem to two LNAs but the oscillations still occur. The circuit is for GPS at 1.57542GHz, and I don't really care about wideband performance.
The oscillation is at 1.573GHz at ~10dBm and then a harmon
RF, Microwave, Antennas and Optics :: 03-13-2014 17:07 :: yrrapt :: Replies: 9 :: Views: 847
If you used s-parameters for your coils, the problem can arise from them. HB does not like much s-parameters because they include some discontinuities between the frequency samples ( I have faced to face a similar oscillator was not oscillating with my EM simulated coil defined with its' s-parameters.When I have changed
RF, Microwave, Antennas and Optics :: 03-03-2014 14:27 :: BigBoss :: Replies: 17 :: Views: 2255
I am not following you. Unless you connect some other circuit to multipin connector P1...NONE of the leds will ever light up. Explain what goes on on the other side of P1.
It might be oscillating
RF, Microwave, Antennas and Optics :: 03-02-2014 14:03 :: biff44 :: Replies: 6 :: Views: 806
David, The "N" simply indicates the type of package-DIP, in your case.
Your circuit may very well be oscillating, but not a frequency that upsets your TV or radio. And I think you might want to connect your antenna (whatever it is) to pin 2 rather than where you have it, as it will affect your frequency since it's connected to the capacitor.
Elementary Electronic Questions :: 02-27-2014 21:30 :: barry :: Replies: 12 :: Views: 3434
i'm having trouble with this the output of my 3 stage cmos rectifier is 0.4 with input vrf = 0.25V, then if i connect the rectifier to a non-overlapping and self-oscillating clock and a voltage doubler circuit the output of my rectifier becomes 0.16V and the final output of my voltage doubler is 0.5V..but if i change the rectifier
Analog Circuit Design :: 01-19-2014 07:49 :: millinium :: Replies: 0 :: Views: 737
I agree with johnjoe, "source unleveled" is also a possible warning in case of oscillating amplifier.
RF, Microwave, Antennas and Optics :: 01-16-2014 14:39 :: ferdem :: Replies: 3 :: Views: 1574
...they Also use Comparators without the Stablization capacitor because the WANT the comparator to Oscillate, Why would anyone want a comparator to oscillate? what does it do when it's oscillating? it's at a frequency
In a simplified viewpoint Comparators are designed to operate at open-loop circuits or
Elementary Electronic Questions :: 01-04-2014 02:36 :: andre_teprom :: Replies: 26 :: Views: 1457
Phase shift circuit when output phase is 180 degree has gain 1/29. Conditions for oscillating are satisfied when amplifier gain is 29 minimum. Gain we are talking depends on type of phase shift circuit.
Analog Circuit Design :: 12-20-2013 07:55 :: Borber :: Replies: 5 :: Views: 422
Hysteresis prevents a Schmitt trigger from oscillating when a slowly changing input voltage is near the input threshold voltage.
A Schmitt trigger can convert a sinewave input into a squarewave or rectangular wave output with fast rise and fall times.
A Schmitt trigger can give a logic output when its input voltage is slowly changing.
Elementary Electronic Questions :: 12-18-2013 15:08 :: Audioguru :: Replies: 7 :: Views: 1361
It is oscillating at out of band.
RF, Microwave, Antennas and Optics :: 12-04-2013 14:21 :: BigBoss :: Replies: 7 :: Views: 612
It is for sure an overtone crystal.
This means that the crystal is ct at 1/3 of the oscillating frequency, but if you select the proper harminic, it will oscillate three times the natural frequancy.
Due to parasitics, the natural frequency is not exactely 1/3 of the overtone frequency.
Analog Integrated Circuit (IC) Design, Layout and Fabrication :: 12-03-2013 18:37 :: FANT :: Replies: 5 :: Views: 764
Your circuit does not show its supply voltage (24V?) and frequency of the PWM.
The 1N4007 diode is extremely slow (designed for rectifying 50Hz). Use a fast diode.
It is missing the important low value resistors in series with the gates of the Mosfets that prevent them from oscillating (which makes them hot).
Analog Circuit Design :: 11-19-2013 15:17 :: Audioguru :: Replies: 10 :: Views: 1743
I made "mood lights" with an oscillating fader circuit made with a dual opamp and an output transistor. Three of these circuits drive red, green and blue LEDs. The oscillator frequencies are all a little different so that the three colors add "randomly" and produce millions of colors including pure white and darkness.
Your waveform has square-wave
Elementary Electronic Questions :: 11-03-2013 16:03 :: Audioguru :: Replies: 2 :: Views: 651
If you measure the difference in frequency between the spurious outputs, this is the frequency at which it is oscillating. This will give you a clue as where your problem is. If its very low frequency then its bias or power supply, if its RF (IF) then its a RF decoupling problem.
I have an ultra low nois
RF, Microwave, Antennas and Optics :: 10-25-2013 15:17 :: avatarET :: Replies: 8 :: Views: 822
Don't stumple upon your sloppy usage of technical terms. Lagging power factor hasn't to do with "negative power". Reactive power is just oscillating energy, no net power is transferred from or to the load.
Electromagnetic Design and Simulation :: 10-16-2013 18:27 :: FvM :: Replies: 10 :: Views: 632
Medical - Power RF - DIY -> Do not know how? Sounds like a dangerous combination.
Doing something like this require basic RF knowledge both theoretical and that you is familiar with instruments to measure and verify if you have designed a 40 MHz/10 Watt amplifier and not a self-oscillating harmonic generator. Even a smaller design mistake and a suc
RF, Microwave, Antennas and Optics :: 10-10-2013 10:10 :: E Kafeman :: Replies: 4 :: Views: 520
The lousy old LM741 opamps are probably oscillating at 15kHz (built on a breadboard?). A heartbeat is at a very low frequency. Your circuit has two lowpass filters that eliminate 15kHz and other high audio frequencies.
Analog Circuit Design :: 10-04-2013 16:25 :: Audioguru :: Replies: 3 :: Views: 708
The opamp has such a high gain that when the circuit is built on a breadboard then it oscillates. When oscillating, its output is switching high and low at a high frequency. Your multimeter is measuring the average DC output voltage which is near half the supply voltage.
Usually, a comparator circuit has hysteresis (a little positive feedback) so
Analog Circuit Design :: 09-23-2013 12:35 :: Audioguru :: Replies: 3 :: Views: 498
R5 is loading down R4, C4 so that it does not begin oscillating. Add another opamp to buffer R4, C4 and drive the output.
Analog Circuit Design :: 09-02-2013 01:44 :: Audioguru :: Replies: 17 :: Views: 1604
well, either u are dividing the 10 MHz reference down by 2 somewhere in the chip, or u have an oscillating op amp somewhere.
RF, Microwave, Antennas and Optics :: 08-23-2013 15:02 :: biff44 :: Replies: 4 :: Views: 722
yeah it is possible, but even if out of band, will probably not have too much loss. more likely your oscillator stops oscillating with the load u have. Try a short length of straight waveguide between the two to see if it works then.
RF, Microwave, Antennas and Optics :: 08-06-2013 13:38 :: biff44 :: Replies: 1 :: Views: 399
With the inverting input shorted to output the opamp is probably oscillating. This will make it get warm but shouldn't kill it as it has thermal protection. You would need to check with a high bandwidth oscilloscope as it will be around 400MHz.
I would probably either use a fast opamp to drive a MOSFET or a MOSFET driver IC driving a MOSFET. Ano
Analog Circuit Design :: 07-11-2013 06:20 :: keith1200rs :: Replies: 9 :: Views: 908
It may not oscillating...you have to probe the output .. n check o/p frequency on might amplifing input noise..
Analog Circuit Design :: 06-10-2013 06:32 :: amitjagtap :: Replies: 4 :: Views: 647
Without knowing your circuit, we can hardly determine why it's "oscillating".
Analog Circuit Design :: 06-03-2013 11:34 :: FvM :: Replies: 93 :: Views: 5822
Plese provide some self oscillating techniques for a flyback transformer
Power Electronics :: 05-21-2013 15:08 :: phobos1 :: Replies: 0 :: Views: 705
I would think that your layout is unstable and the FETs are oscillating in the UHF region and changing the length of leads/decoupling capacitors is stopping the oscillations. Try ferrite beads/10 ohm resistors on the FET gate leads.
Analog Circuit Design :: 05-14-2013 11:59 :: chuckey :: Replies: 5 :: Views: 589
I agree that it can be a problem of closed loop responses of both the source and the LD300 combined.
Did you try to see what is the waveform at the input of the LD300 ?
In may be oscillating.
Elementary Electronic Questions :: 05-04-2013 17:00 :: albert22 :: Replies: 6 :: Views: 930
I am trying to buffer a signal on a capacitor using lt6202 using differential configuration. All resistors are fixed 100kohm in the differential configuration. The signal at the input is a clear signal oscillating between 1.5 to 3.5V @ 230kHz. The signal can be seen at the output but it is not stable. It is driving a 47k load with parallel to 1k an
Analog Circuit Design :: 04-13-2013 16:55 :: seyyah :: Replies: 5 :: Views: 538
The only difference between sound and electromagnetic wave is that sound waves are longitudinal and the elmag wave is made by charges oscillating normally to the direction of propagation.
Sound is an elastic wave, air or mass particles oscillate forward and backward. Without air or other material sound cannot propagate.
Elmag wave is generated by c
Elementary Electronic Questions :: 04-09-2013 19:22 :: jiripolivka :: Replies: 3 :: Views: 666
1.3GB is a lot of memory, maybe your machine VM settings
have limited the swap space or whatever. But the problem
may be more about generating huge globs of useless data
(such as when some nodes are oscillating at high frequency
I'd start with inspecting the circuit and looking for crazy-small
timestep reported, which might indicat
Analog Circuit Design :: 04-03-2013 16:53 :: dick_freebird :: Replies: 1 :: Views: 1825
a very basic answer:
The kHz or MHz signal u r talking about is a square wave oscillating at 50% duty cycle. For eg. a sine wave is calculated for particular freq (specially line freq of 50/60Hz) in digital domain for a single period or cycle which is in range of 0 to 1 values. The output is then converted to integer values by multiplying by some h
Analog Circuit Design :: 03-27-2013 06:23 :: ashugtiwari :: Replies: 5 :: Views: 699
I'm not sure if it works exactly as shown. Most likely, it doesn't achieve good switching performance in the present form. But there are similar circuits performing better.
A good self oscillating inverter would work over a large load range with good efficiency. A BJT inverter would at best use current feedback to the base, and the frequency mus
Power Electronics :: 03-20-2013 14:05 :: FvM :: Replies: 2 :: Views: 523
The transistor inside of SA602 used as an oscillator is at pins 6 and 7. The transistor is internally biased and don't need external bias.
Seems that you got the rest of the chip oscillating, and when you disconnected the resistor from pin 1 actually you stop this oscillation.
Verify first if the oscillator works, supply the chip, and don't connect
RF, Microwave, Antennas and Optics :: 03-17-2013 21:37 :: vfone :: Replies: 6 :: Views: 1854
I am realizing a low voltage bandgap(shown as "sch.png"). I use a schmitt trigger to turn off the bandgap's start up circuit. The upper threshold voltage of the schmitt trigger is 500mv, and the lower threshold voltage is a
Analog Circuit Design :: 03-11-2013 04:57 :: ivyahoney :: Replies: 3 :: Views: 674
that funny gain glitch at 300 MHz might be an oscillation. When it is running, carefully use a spectrum analyzer to see if there are any spurious oscilations going on. Remember that a spurious oscillation in a 20W amp might actually be oscillating at up to 40 watts or so, so use pads!
RF, Microwave, Antennas and Optics :: 03-01-2013 21:19 :: biff44 :: Replies: 7 :: Views: 1325
When the output V is the same as supply V, it suggests the chip is no longer oscillating. It may stay on, which drains the supply. Or it may stay off, which lets supply V through unhindered to the output stage.
It is a big jump to boost 1V to 3.3V. Whatever the load requires, a boost converter must draw 4 or 5 or 6 times that much current from the
Power Electronics :: 01-26-2013 22:01 :: BradtheRad :: Replies: 2 :: Views: 787
What you have done looks good, The two possibilities as to why it does not work are the crystal not oscillating, try a simple RC oscillator instead, or you have not programed the configuration word correctly. Don't forget to turn off the watchdog timer and set the oscillator mode correctly.
Microcontrollers :: 01-17-2013 02:12 :: pjmelect :: Replies: 8 :: Views: 2314
The frequency is a measure of oscillating charges; it is defined by signal source.
Wave length is a parameter of electromagnetic wave with a given frequency, measured along the line of propagation. If the wave propagates in air or vacuum, the equation c = f. lambda is valid , where c is the speed of light in vacuum.
If you propagate the wave in a
RF, Microwave, Antennas and Optics :: 01-08-2013 12:56 :: jiripolivka :: Replies: 6 :: Views: 675
If the unit is oscillating there is an AC signal across the Resistor so it will interact with the "R" reading (R = V/I).
Also a Multimeter(MM) uses a small voltage to sense the impedance so the MM will add voltage top that circuit
and could change the natural Frequency of Operation.
As an experiment see if your resistors change value while the c
RF, Microwave, Antennas and Optics :: 12-10-2012 20:43 :: Element_115 :: Replies: 10 :: Views: 1566
Check the logic, do you see it oscillating? The output state might be unexpected or possibly unwanted, that's it.
Elementary Electronic Questions :: 12-02-2012 17:44 :: FvM :: Replies: 1 :: Views: 398