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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 ...
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...
First I noticed that clock begins before chipselect gets pulled low on SPI. After eliminating potential sources I started to suspect the scope. I connected all 4 channels to function generator at d...
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...
I am trying to find the AC analysis of a BJT Hartley oscillator but I cannot continue. How do I find the voltage gain? When no feedback is there, we just find the output resistance and the current...
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 ...
I am designing a low-pass filter with cut-off frequency = 100Hz and after the cutoff frequency from -3dB to -10dB the average decrease in db/Hz = -0.1 db/Hz.I know how to design a low-pass filter ...
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...
Signals with frequency above the cutoff frequency of a transmission line cannot be transmitted through the transmission line. But how can I calculate the cutoff frequency of a single phase transm...
I have been observing these little cases hanging to the wires from a long time and almost everywhere but unable to find out what it is.I am not sure whether they are related to any electric...
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...
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...
Suppose we have this graph: How can we find the operating point (Q)?In common emitter collector we just draw a line from the vertical axis (Ic) at the point (0,VCC/RC) to the horizontal axis a...
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...
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...
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...
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: ...
I am calculating the base current of transistor Q1. To simplify the circuit equations, I applied the Thévenin's theorem twice and converted V1 and R1, R2 into Vth and Rth as shown in the image. Vt...
I know that in transistors there is base, collector and emitter, and in FETs there is gate, drain and source, but what is the fourth grounded connection opposite the gate in this NMOS circuit?
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=\...
I'm designing a high side current source that can be controlled with a Digital-to-analog and can source up to 100mA with voltage supply up to 36V. By high side I mean one side of load will be alwa...
I want to design a simple battery charger using MCP73831/2. This chip has a 3-State state pin according to the table below: I have a 3.3V MCU and I want to connect this pin to a GPIO. The MCU is...
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 the following problem: - Using Wikipedia I find that during CCM we have the relation: - $$\frac{V_{out}}{V_{in}} = -\frac{D}{1-D} $$ Solving for $D$ and inserting values gives me $...
I want 3 SMPS (AC-DC) : Vout/Iout - 5V/20A , 12V/75A , 24V/30A Vin (AC) ~ 220V/50Hz I want it such that I can use Hard & Soft Kill Switches for turning off. Can you help me with the same. I tho...
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...
Homework problem A MOSFET has a power dissipation of $P_{d} = 10\text{W}$. The MOSFET is mounted on a heatsink. There is an isolation pad between the MOSFET case and the heatsink. We are given t...
I've seen a few different circuits (a) (b) (c) (d) described as "an O-ring circuit" or "an optimal O-ring circuit". What does the "O" and the "ring" refer to in such circuits? How do "O-ring circ...
Which important system design parameters need to be locked in order to estimate the maximum allowable level of the input voltage ripple of an SMPS? I have encountered ballpark figures of <1%, &...
Recently I have heard this opinion from experienced engineers when discussing PCB design software. The common opinion was that Allegro and Altium are supposedly professional programs whereas Eagle ...
I saw that this PCB socket: Is marked as pressfit for non-plated holes. However, can it be used with plated holes as well, or will it damage the plating inside?
Suppose we have a sine signal applied to a inductive load. Is the inductance of the load changed if the frequency of the signal is changed?
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...
The premise In a recent video by the pop-sci channel Veritasium, the concept of the flow of electricity and energy transmission in a circuit was discussed. In that video a thought experiment is pr...
I was looking at different transistors, especially MOSFETS and I saw that N type MOSFETs seem to be way more popular to be used in circuit design. Is there a reason for that, or am I mistaken?
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...
I recently started working at a construction office in another country. I usually listen to music when working, and I saw a headphone jack in the wall, so I thought it is radio or something, I plug...
According to Signal processing and linear systems by Lathi, the transfer function $H(j\omega)$ does not exist for systems with poles in the RHP: - This makes sense to me, since $H(j\omega) = \fr...
I have a 30MHz TCXO circuit (TXCO datasheet) like this serving as local oscillator to a RFIC: The RFIC manufacturer recommends to "add filtering caps" for high RF output cases. That is >20d...
I have designed a graph of the current in a photoresistor related to the brightness of light which hits the photoresistor. Our professor told us that it is more correct to draw the Current/Brigh...
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...
As we know there exists numerous different kinds of PCB CAD software. The big ones seem to be Eagle, KiCAD, Altium, OrCAD, Solidworks, DesignSpark and probably a few more. When it comes to mechani...
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...
I need to design a simple flyback converter like this: - I want to control duty cycle from another circuit such as an MCU but, I'm unsure how to proceed. My requirements are: - Input voltage 125 ...
I have a PIC32MZ2048ECG064, a 64-pin 32-bit microcontroller with 512kB RAM. This is not enough for my purposes, I need to extend it by at least 32MB, preferably 64 or 128. I believe this means I ca...
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...
One standard used for spacing conductors based on voltage is the IPC-2221. This standard differentiates spacing requirements for inner and outer conductors. Does the IPC minimum separation betwee...
Differential pairs, such as for ethernet or a CAN bus, can be designed to be loosely coupled or tightly coupled. For a loosely coupled differential pair, the odd-mode and even-mode impedances are ...
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...
In a 3 phase Star source-Star load circuit the phase voltage has different phase than line voltage and in a 3 phase Delta source-Delta load circuit the phase current has different phase than the li...
