New answers tagged frequency
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From personal research I have found that the ohmic resistance of a diode is approximately 25Ohms.
The total resistance will bw 2x25 = 50Ohms.
The initial energy stored in the capacitor is 1J.The power dissipated on the resistor is 10^5x50= 5x10^4=10^3/2 W.
L = 1H.
C = 20mF.
The frequency of the RLC oscillation is 1/sqrt(LC) = 1/sqrt(1x10^3x20) = 1/0.15 = 6....
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here is a simulation that I just quickly did
and here are the results:
from the simulation, it can be seen that it took ~670,000 seconds (=7.75462963 days) to discharge the capacitor. I have chosen capacitor value to be 2 micro farads and initial voltage of 1000 volts, which means it will store the energy of 0.5 * 2 * (10^-6) * (1000) * (1000) = 1 J
I have ...
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This self answer is based on the comment of Chriss Stratton, who have opened to me the exciting world of switched capacitor filters (the part of the question about possible heterodyning IC has been answered by analogsystemsrf). I think his answer is interesting for many reader, hence this edit. Basically, a switched capacitor acts like an RC circuit, whose ...
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Look into the MT8870 DTMF (Dual tone multi frequency) decoder IC. DTMF is sometimes called Touch-Tone, and every digital phone uses these frequencies. In each case 2 frequencies are mixed together. They have no mathmatical relationship to avoid harmonic resonance. Example: The dial-tone is a mix of 350 and 440 Hz sinewaves.
Link to PDF The MT8870 outputs a 4 ...
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The NE602A from Philips has differential RF inputs and differential IF outputs, with a single-ended (use a series DC_block capacitor) Local Oscillator pin. 8 pin package.
The NE602A onchip function is a double-balanced mixer (which nulls out the LO injection and the RF injection, as much as silicon_layout_symmetry can achieve) with response down to DC. Oh, ...
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The tolerances are listed in the datasheet, pages 40 and 41.
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This answer is actually @glen_geek's who commented on Jun 21 at 1:23:
That upper right knob "VARIABLE" looks rotated counter-clockwise. Should be turned clockwise to the "CAL" position.
and it is true. I have no idea why I didn't notice the discrepancy, I should have heard that 440 Hz is nothing like the tune fork and the 1 kHz of which ...
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Let your filter have a set A of capacitors, inductors and resistors. Let your frequency be just now = Fx. Imagine you calculate the complex impedances at frequency Fx of the set A to a list L.
Think the case you do frequency scaling which makes the filter to have the values of all operating parameters exactly same at frequency Fy as your original filter had ...
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you can find mica compression trimmers, with a dozen layers of mica, on that 2cm by 3cm ceramic_base, providing 5:1 or 10:1 change in capacitance, with well over 100pF final capacitance.
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Don't you just hate when we say, "well, it depends"?
Your 30mH coil might have been designed for an application at a much lower frequency. Its inductance in the 30-40 kHz range may be much different, requiring less capacitance than 800 pf for resonance. Having a handful of 100pf capacitors to apply in parallel may be a good plan.
If you are adding ...
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At your frequency, the 8 parallel capacitors will be the same as 800 pf.
Lead inductance won't be relevant.
However, the tolerance of your original capacitor and the 100pf capacitors may come in to play. You could measure the capacitance if your multimeter can measure capacitance.
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If I searched right, the unit has a maximum output frequency of 1MHz. A 1MHz wave has 300m wavelength in free space. It will be slightly longer in a cable. So the cable you will use, will be electrically short for sure, and only the capacitive loading of the cable and thus the bandwidth is to be assessed. Such a coaxial cable should have roughly 100pF/m ...
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RG59 Coax is 75 Ohms and as I recall 30pF/ft.
Twisted pair impedance and pF/ft depend on twists /ft.
The fewer twists, the higher the impedance and inductance must be considered as well.
It becomes a matter of tradeoffs whether you have rounded edges or ringing or attenuation with properly matched RC impedance divider like an 8:1 to 75 Ohms or unshielded ...
answered Jun 28 at 4:14
Tony Stewart Sunnyskyguy EE75
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At the frequencies your using there is little effect in using a lower impedance cable. However you will want to terminate it with a 600 ohm load so the source can still drive it at full voltage.
Frequencies at or above 50MHZ are very fussy about impedance matching and standing waves and you are nowhere near that high in frequency.
600 ohms is typical for ...
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600 ohm is unrealistic; needs center conductor about the size of an atom, shield with diameter of the universe, from what I heard.
Use the 75 ohm; you are not expecting standing waves, so don't worry.
Regarding achieving 600 ohm COAX is not the same as achieving 600 ohm TWINLEAD. Pole/crossbar mounted telephone cables are twinlead.
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Just look in the respective data sheets: -
I do not know how the capacitor into the diode and the MOSFET evolve in
function of the frequency
You can rely on the capacitance values above for up to 1 MHz but gradually, as frequency rises you will get inductive properties of the devices coming into play and the data sheets are pretty lean in this respect.
As ...
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The problem is that when I try using the general formula for inverse Fourier transform I get stuck by the infinities.
The reason for this is that a cosine function has infinite energy, and therefore its Fourier transform is not a well defined function. Instead, one usually uses the Fourier series for periodic functions, since that integral will converge.
...
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The relevant physics here is the LC tank formed by the secondary coil, where the capacitor is the 'stray' or 'parasitic' capacitance. The feedback from the secondary coil provides feedback to the remainder of the circuit, which only exists to drive the tank resonantly.
To fully understand this, we must note that the other side of the secondary 'capacitor' is ...
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It's the clock at which bytes encoded to 8b10b TMDS symbols are sent over HDMI.
For 24-bit resolutions, pixel clock rate matches the symbol clock rate.
Edit: Quote from the linked programmer reference manual:
The PLL output frequencies are 5x the symbol/TMDS rate, which is 1/2 the bit rate.The PLL output is divided by 5 to become the symbol/TMDS clock ...
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As Kevin White has mentioned, the Pierce oscillator uses just one inverting gate, and to me that feels like exactly the correct approach. Not sure about "series resonance" (I recall reading something about different resonant modes in the crystals, and crystal cutting geometries) but my general idea is, that the crystal, being a two-pin device, ...
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Most such oscillators require external 22pF capacitors from each end of the STAL to achieve a nete phase inversion to implement proper oscillation.
Since 22pF is LARGE, the silicon area likely is not used to provide those 44pF caps (which will vary as the manufacturer recommends for your frequency). Does your IC include those? I see two resistors, value ...
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The MV2201 has a nominal capacitance of 6.8 pF at 4 volt DC and can span a range of 1.9 to one when the DC control voltage changes from 1 volt to 10 volt. So, the range might be from 8 pF (@1 volt) to about 4 pF (@10 volts).
Now ask yourself how much that is going to change the main frequency of the oscillator given that the varactor diode is, in effect, in ...
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