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The small signal analysis of a BJT when the BJT is in amplification mode: is easy.However what happens when the BJT is in saturation mode? Can we replace the dependent current source with a r...
Assume that I have some generic antenna connector, followed by a pi-filter/50ohm impedance matching components, then a DC blocking cap (as per the RF switch recommendations) and then a RF switch fo...
Instead of using a buck or a boost converter can we use for DC-DC conversion the circuit Im going to describe in the next lines? First we begin with a Hartley oscillator whose output is fed into ...
Signal characteristics are: 0 to 3.3V span 0 to 100Hz range( there will be noise superposed on top with unknown characteristics) Output resistance Rout=4700 ohm I want to sample that with a...
I have learnt that if we have 2 parallel conductive plates and we seperate them the capacitance is increased if we put a good conductor between the plates. Now the resonant frequency of a inductor...
I was watching a video from EEVBLOG about bypass capacitors, and he presented a theory that randomly connecting different values of capacitors in parallel can create unexpected impedance spikes: ...
The thermal stability coefficient is defined to be: $S = \frac{dI_{C}}{dI_{CBO}}$ where $I_{CBO}$ is the reverse current of the BJT when voltage isnt applied to the base of the BJT. In case of a ...
I am trying to analyse what is controlling the load current in the below Darlington configuration. Is it the base current of transistor Q3 which is controlling current through R14 / emitter curr...
RF novice here. If using a superheterodyne receiver for the purpose of FM/FSK modulated signals, I'm wondering if the location of an optional automatic gain control (AGC) circuit is always placed o...
A taper pad is a resistive attenuator that maintains impedances on both ports and provides a specific amount of gain-loss ($A_{12}$): - I have derived formulas for each resistor (that I know to ...
I have designed a PCB that I need to work in which a microcontroller drives a 24 V brushed motor. The input power to the board is 24 V, this is then lowered to 5 V by a step down converter, and thi...
The circuit above is used to control a 240W ceramic heater by means of a PWM signal at 30Hz, generated by a microcontroller, with 5V logic. The input is a standard 280W AC-DC external power adapt...
What is a difference between SPI stream and memory mapped SPI? PS SPI is a peripheral.
I am analysing a pulse transformer which is required to transfer below communication protocol pulse from primary to the secondary side. The pulse duration is 32 μs and off time available to reset t...
Hi guys,I'm designing a multiple output flyback converter with 2 outputs at 10v@1 Amp and 5v @ 2 Amps .Input is 20 V dc Im having some problem with the implementation of closed loop. Open loop res...
I was studying the Re model of a transistor: But the Re model for 2 different configurations (common emitter and common base )turns out to be the same! I don't know why I am really confused.How...
If I connect a battery to an LC tank and then to an antenna and then on the other side at a distance x, I connect an antenna to another LC tank and this to a diode and this to an LED, Do a I have a...
Inside a op-amp after the stage where the differential signal is converted to single ended , there is further amplification of the DC signal.For AC signals there is a capacitor parallel to the tran...
If we want to divide two numbers I have problem implementing this logic.I am posting 1 images with 2 different steps to the solution. In example a) the most significant digits of the divident >...
This question is asked in an addition to https://electrical.codidact.com/posts/276436 Here is a Flyback converter mentioned there: Design parameters are: Input voltage 125 volts Output volt...
We identify semiconducting electrical components this way: The first digit represents the number of pn junctions inside the semiconducting device The two or more digit number starting at position...
I am generating files for manufacturing my design in Altium 22 and ordering through Eurocircuits. What I noticed during the ordering process is that the rotation of many components (and sometimes ...
Im designing a Hartley oscillator this time with a opamp providing the open-loop gain.I have tried drawing the small-signal analysis of my circuit to use KVL and KCL to find the conditions of opera...
I am designing a PCB with somewhat limited space. To save space, I am placing some vias on component pads. However, I am not sure if this is a good practice in PCB design. As far as I understand, t...
I have this circuit: I think that R3 acts like a feedback path from the output to the input.However I am not sure what will happen if I change the value from 100Ohms to lets say 1kOhms. I have ...
Im designing a high-pass filter which has a gain of -8dB at half of the roll-off frequency and I am stuck ,I dont know how to continue the design. In the bode plot of that filter we have 2 points:...
A full wave rectifier converts a sine wave to DC pulsed signal of double frequency. Is there a circuit which does the reverse process?
I have decided to try design a band-pass filter with a cut-off frequency of 10kHz and bandwidth of 2 Hz. $$ \frac{1}{\sqrt{LC}} = 10001 \rightarrow LC = 1/100020001 sec^{2}$$ $$ \frac{R}{L} = 2...
A while ago I made a question about the monostable multivibrator .Lets get a picture of it: When switch is closed it enters its unstable state and it eventually returns to the stable state Howe...
In monostable multivibrators we use a trigger signal applied to the base of the transistor which is usually off to enter the astable region Can we instead have a pin which is connected directly ...
I saw that equation of reactance is written like this $$I=\frac{V}{|R+X_L j|}$$ $$I=\frac{V}{|R-X_c j|}$$ When there's capacitor and inductor in a single circuit then it is written like : $$I=\...
How can we find the equation of current and voltage of a capacitor circuit if the input voltage is AC without using the impedance formula Xc = -jωC?. We have for homework to find the equation of...
My scenario is this: radio equipment controlling an overhead crane inside a steel mill. Specifically it is used for transporting melting pots. With the current, unfortunate installation, the antenn...
My goal is to make an RC car, and I have a couple of questions regarding driving the brushed DC motor. Schematic for half of my H-bridge looks like this for now (it will be identical on the other s...
I have a Rigol DS1104 oscilloscope. Last week I stood up quickly from my table and saw a spike on the scope. Right now all the channels have a DC offset when probe is connected to ground or unconne...
In the design of a power converter, picking the appropriate capacitors for the input and output of the converter is quite important. It is relatively easy to calculate the necessary values for a gi...
On the LEFT is what I just bought today — Globe Electric 4W (40W Equivalent) Daylight (5000K) Dimmable LED Light Bulb, G9 Bi-Pin Base, 400 Lumens, 15,000 H. Here's Globe Electric's Dimmer Compatibi...
If we have the transfer function of a LC high pass filter: $H(s) = \frac{sL}{sL+\frac{1}{sC}}$ If we want to find the pole of that filter in the end we get: $s = \frac{j}{\sqrt{LC}}$ and for a ...
Assuming we have a voltage regulator : Why do we have to ground Vin and Vout using 2 capacitors just like that?Co could be to provide a low resistance path to GND at high frequencies but what is...
I'm designing a PCB for a project. 12 volt input power supply is provided externally, so the user will buy a power adapter, so putting a popular DC jack on the PCB is the best choice.
If we a varactor and we want to control let's say the resonant frequency of the circuit ,in my schematic we must add R1 correct?Else we create a low resistance path for current to flow not through ...
This question is related to my previous question. I want to drive a brushed DC motor using H-bridge. To power the motor two 18650 cells will be used in series. The issue is that I want to limit th...
While doing some reading on RF designs I ran across this paragraph: I have never designed an RF circuit, but all the PCB trace antennas I have seen on development boards are square. For example,...
In circuit analysis why always the power has upper hand over energy? Even if we consider a simple battery circuit with a bunch of resisitors we always use the terms power delivered,absorbed,consump...
Can we find the internal resistance of a multimeter ,when we use the multimeter like a ampmeter, from its datasheet? I am trying to find the internal resistance of IDM 505 and I went to the datash...
How to find the equation of voltage of the top common node of R1,L1 and C1 after the switch is moved?
Based on this paper on Wiki a diode can be described as a frequency mixer due to the exponential relationship between current and voltage.What I don't get from which point to which point do we meas...
Which capacitors have smaller self resonance frequency?I would bet my money on electrolytic capacitors because they are usually much bigger than the ceramic capacitors however I don't know if they...
Intro Hi everyone, I have a question about the practical use of a PTC (positive thermal coefficient) resettable fuse. I've never used one before, but I'd like to add one to a DC motor circuit to p...
How can we extract a DC signal from a mixed signal?If we want to extract the AC component of a signal we can use a blocking capacitor to remove any DC offset but how do we achieve the opposite?Can ...
