Activity for Andy aka
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Edit | Post #283993 |
Post edited: |
— | over 2 years ago |
| Edit | Post #283993 |
Post edited: |
— | over 2 years ago |
| Edit | Post #283993 |
Post edited: |
— | over 2 years ago |
| Edit | Post #283993 |
Post edited: |
— | over 2 years ago |
| Edit | Post #283993 | Initial revision | — | over 2 years ago |
| Answer | — |
A: Coupling of inductors > Which will be the total inductance of this circuit? Quite simply, if both the individual 1 henry inductors are perfectly magnetically coupled then, the net inductance will be 4 henries. If both 1 henry inductors are totally uncoupled, then the net inductance is 2 henries. This can be... (more) |
— | over 2 years ago |
| Comment | Post #283960 |
*Now current entering one coil marked with a dot, produces a current exiting the couple coil at its dotting end.* - this is incorrect. Induction causes a voltage to be induced. Think about it - how can a current be generated by L2 in the opposite direction to that flowing in L1 when they are in serie... (more) |
— | over 2 years ago |
| Comment | Post #283430 |
A signal that cannot change is generally recognized as being 0 volts. (more) |
— | over 2 years ago |
| Edit | Post #283389 | Initial revision | — | over 2 years ago |
| Answer | — |
A: Adding resistance to varactor circuit > in my schematic we must add R1 correct? Yes that works except: - Image alt text > One last question if we deliver voltage to a house are there varactors which can handle 120V AC No, they don't exist. (more) |
— | over 2 years ago |
| Comment | Post #282733 |
Where did you uncover the equation? What document did it come from? (more) |
— | almost 3 years ago |
| Comment | Post #282738 |
Why should we be able to transmit power from an antenna billions of miles? What transports this power? You need to study EM field radiation. That's a far bigger issue than a wires apparently being an open-circuit. (more) |
— | almost 3 years ago |
| Comment | Post #282746 |
If you leave your name, address and utility company reference, I'll contact them on your behalf and arrange for you to go on a low-tariff supply. (more) |
— | almost 3 years ago |
| Edit | Post #282725 | Initial revision | — | almost 3 years ago |
| Answer | — |
A: Diodes used in mixers There are plenty of ways a single diode and a couple of resistors can perform multiplication (RF mixing). Consider this circuit that takes two inputs (a 1 MHz sinusoidal carrier wave and a 10 kHz triangle wave used to modulate the carrier): - Image alt text Now look at the signal on the cathode... (more) |
— | almost 3 years ago |
| Edit | Post #282710 | Initial revision | — | almost 3 years ago |
| Answer | — |
A: Extract DC component of mixed signal > How can we extract a DC signal from a mixed signal? You use a low-pass filter with a cut-off frequency that is significantly lower than your lowest AC signal frequency. If you need better filtering use a higher order low-pass filter. If you need both fast response to the DC level and high AC ... (more) |
— | almost 3 years ago |
| Comment | Post #281971 |
EMI could do that. Maybe make an antenna that works in a close but quiet part of the spectrum and test? (more) |
— | almost 3 years ago |
| Comment | Post #281967 |
Pick several and fit them all to cover as many variations as you think are required. Also fit inverting links so that a barrel jack with the centre pin with opposite polarity can be reversed. Or use a bridge rectifier to automatically produce the correct polarity.
(more) |
— | almost 3 years ago |
| Comment | Post #281634 |
@2kind ESR is very important. If the ripple current is high such as in inductive chargers using resonance then the ESR can dissipate enough heat to burn a capacitor. Plenty of other applications require low ESR. (more) |
— | almost 3 years ago |
| Edit | Post #281634 |
Post edited: |
— | almost 3 years ago |
| Edit | Post #281634 |
Post edited: |
— | almost 3 years ago |
| Edit | Post #281634 | Initial revision | — | almost 3 years ago |
| Answer | — |
A: Capacitor ESR vs. Impedance > Which graph on the picture above better represents real-world use-case? They both represent real-world use cases. The impedance graph informs you how much ESL (effective series inductance) the capacitor has and, at the series resonance point you can evaluate the ESL value with a simple formul... (more) |
— | almost 3 years ago |
| Comment | Post #281165 |
Yeah I think the 10 nH is a tad high compared to the real true value needed (8.7 nH) (more) |
— | about 3 years ago |
| Comment | Post #281165 |
You didn't say what calculator you used or what values it came up with. (more) |
— | about 3 years ago |
| Comment | Post #281226 |
Good result Leroy (more) |
— | about 3 years ago |
| Edit | Post #281165 |
Post edited: |
— | about 3 years ago |
| Comment | Post #281165 |
Regards LoRa, I can't answer that so maybe address it to the OP. (more) |
— | about 3 years ago |
| Comment | Post #281165 |
@Lundin trying to target a specific frequency with a notch filter is haphazard and relies on low drift components. Having said that, you can add a capacitor across the inductor in the PI filter and get an elliptic (Cauer) filter that does do that (but at the expense of not being great if the bandwidt... (more) |
— | about 3 years ago |
| Comment | Post #281165 |
@Lundin a PI filter is the archetypal impedance matching network to turn to. The fact that it can have seriously good attenuation characteristics outside the pass band is a major bonus. Usage of PI filters in reduction of EMC isn't really using them as a proper (intended) circuit but just as a bidire... (more) |
— | about 3 years ago |
| Edit | Post #281165 |
Post edited: |
— | about 3 years ago |
| Edit | Post #281165 |
Post edited: |
— | about 3 years ago |
| Comment | Post #281165 |
... If you look at the link to the calculator in my answer and scroll down I've made a [5 stage](http://www.stades.co.uk/Impedance%20TX/Simulations/PI%20cascaded.png) filter and that has a monstrous and slope [here](http://www.stades.co.uk/Impedance%20TX/Simulations/PI%20cascaded%20simulation.png). ... (more) |
— | about 3 years ago |
| Comment | Post #281165 |
@Lundin if the simpler pi filter provides enough attenuation then no need to go to a more sophisticated filter. However, you can absolutely stack end-to-end pi filters to get both impedance matching and steeper roll-off..... (more) |
— | about 3 years ago |
| Edit | Post #281165 |
Post edited: |
— | about 3 years ago |
| Edit | Post #281165 |
Post edited: |
— | about 3 years ago |
| Edit | Post #281165 |
Post edited: |
— | about 3 years ago |
| Edit | Post #281165 | Initial revision | — | about 3 years ago |
| Answer | — |
A: Filter RF Harmonics With Additional PI Network > Since we are trying to keep the impedance matched to 50 ohms, what is the best strategy to approach this circuit? A low pass \$\pi\$ network seems a good route to go. Basically your \$\pi\$ network is designed to do two important things: - - Impedance match a 50 Ω source to a 50 Ω... (more) |
— | about 3 years ago |
| Edit | Post #281141 |
Post edited: |
— | about 3 years ago |
| Edit | Post #281141 | Initial revision | — | about 3 years ago |
| Answer | — |
A: Why is it is always power consumption or power delivered more in usage? > In circuit analysis why always the power has upper hand over energy? One obvious reason: - If we calculate how much power a resistor dissipates we can calculate how hot it will get (knowing it's thermal resistance and ambient temperature and some other factors). We need to know how hot stu... (more) |
— | about 3 years ago |
| Comment | Post #281064 |
What are you trying to achieve with your modulated signal? OOK? Non-suppressed carrier? Suppressed carrier? You need to be clear about your goals. 555 timers are normally suited for anything but basic modulation schemes. (more) |
— | about 3 years ago |
| Comment | Post #281059 |
Have you tried looking for wide bandwidth unity gain stable op-amps? (more) |
— | about 3 years ago |
| Comment | Post #281021 |
*Can there be a global EMP disaster* - I'm sure there could be one day (more) |
— | about 3 years ago |
| Comment | Post #280791 |
24 volts is probably used more often than 28 volts and quite possibly 72 volts is more common than 60 volts. 15 volts is also commonly used. (more) |
— | about 3 years ago |
| Edit | Post #280733 | Initial revision | — | about 3 years ago |
| Answer | — |
A: Is it always necessary to use the ground terminal of the oscilloscope probe? To add to Olin's excellent answer, if you were probing on a digital IO line in order to view a fast changing signal, without the local ground clip (or spring) grounded close to where you make the measurement, you would, in effect, be adding an antenna to that IO line and causing interference to other... (more) |
— | about 3 years ago |
| Comment | Post #280600 |
Use a simulator. Really, use a simulator. If you are not able to use a simulator let me give you some very, very good and strong advice: Get a simulator and learn how to use it. (more) |
— | about 3 years ago |