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H: How can I connect a USB keyboard to a DE1-SoC?
I recently got a DE1-SoC development board from Intel and I wanted to use it to instantiate a computer design I created while following along the Nand2Tetris course on Coursera. Unfortunately, this design requires a keyboard to be connected to the board and I do not ha... |
H: Self-made Schottky transistor doesn't behave as I'd expect
For a project of mine I need to generate UART-like signals with higher voltage (up to 18V) and a baudrate of 115200 bps and later possibly 250000 bps. I tried a basic BJT level shifter which worked as shown below:
(here and later: yellow in IN, green is O... |
H: Voltage induced in aircraft high-tension magneto ignition system
Why is there no voltage induced into the secondary winding (in high-voltage step-up transformer) when the ignition switch is closed (OFF)? When the current flows in the primary winding of the coil a magnetic field is generated. This interacts with the... |
H: Can I touch resistor connected to mains power?
Can I touch resistor connected to mains power?
simulate this circuit – Schematic created using CircuitLab
AI: Of course you can.
Of course, a certain percentage of the times you do that you will die, but that's not what you asked.
Your circuit, as shown, is guarant... |
H: Why does an Instrumentation Amplifier need a reference?
I am working with the INA826EVM board and I am wondering why it needs an additional op-amp for a reference in the Instrumentation Amplifier?
AI: The core of an instrumentation amplifier is a differential amplifier, it simply subtracts voltages. To increase the... |
H: Switching Regulator Voltage Dropping Unexpectedly
I am trying to determine what exactly is causing the below switching regulator/ DC-DC converter module to not maintain its rated output voltage.
http://www.meanwellusa.com/productPdf.aspx?i=794
I am using the SPBW03G-03, which has a listed maximum output current of ... |
H: Switch high voltage with triggered spark gap
I want to switch a high current/voltage pulse (up to few 10kV, <1kA) from a capacitor as supply. It needs to be cheap and I don't care about efficiency too much yet.
I took a look at using thyristors in series but I think it'll cost too much and could possibly be dangero... |
H: Hold Pushbutton for soft latch after X seconds
What I'm trying to achieve is have a momentary push button that must be held for say 5 seconds before latching on permanently.
But the button must be held for entire duration or else timer will reset.
I'm looking at 555 timers but struggling to figure out how to auto r... |
H: Why is this BJT Schmitt trigger producing a sine wave?
I am trying to build a Schmitt trigger from a pair of BJTs to convert a sine to a square wave.
The sine wave is from a Colpitts oscillator running at over 150 MHz. I want to measure the frequency using something like the SN74LV4040, which is why I want to squar... |
H: Analysis of a modified Howland Current Pump
I am trying to do an analysis of the following modified howland current pump based on the circuit description in the datasheet of the LMP7701. This is a voltage controlled current pump that is driven by a sine generator with aroung 10 kHz.
simulate this circuit – Schemat... |
H: What if I cut off an NC pin from an IC?
I am designing a circuit using an IC, LTC7004, which is a high-side MOSFET driver. There is one pin (10th) marked as NC.
NC (Pin 10): No Connect. This pin should be floated.
In my PCB design, I'm pulling out a track from the 8th pin which is the pin to connect the source of... |
H: Quartus II selected a signal as a clock in combinational circuit
library ieee;
use ieee.std_logic_1164.all;
entity ALU is
port(
input1: in std_logic_vector(31 downto 0);
input2: in std_logic_vector(31 downto 0);
reset: in std_logic; --Asynchronous Reset
operation: in std_logic_vector(3 downto 0);
... |
H: Slow build-up and discharge LED effect
I was trying to build a circuit that if switched on would slowly (in span of of 1~5s) light up around 20 LEDs - progressively, not all at once.
To achieve that i used one capacitor to initiate the "build up" effect (and discharge when switched off) and then used NPN transistor... |
H: I have an outlet adapter that is clicking at 260bpm. What is happening?
I plugged this adapter, GE Grounded Adapter-Spaced Six-Outlet Tap, into my outlet the other day. I noticed a clicking noise in my apartment, and it's coming from the adaptor. I used an online app to measure its BPM. 260 BPM. But 260 isn't an ev... |
H: earthing conductor
I'm studying the subject Electrical Safety in Engineering and a special term really drew my attention. When I tried to google it, no any option was suggested but Protective conductors.
In the presentation slide, the definition of the term is explained in a such way.
**Earthing conductor: A pr... |
H: voltage output and flip flop output
Shown below is the circuit I would like to implement. (the circuit is from this paper).
Basically, it's a circuit designed to cut off voltage when electrochemical etching is done. The sudden drop in current flow is taken as the signal to stop the voltage bias.
I circled the two p... |
H: Adapating a single cell Li-ion battery voltage to 3.3V low power application
I'm planning to use a single cell Li-ion battery to power up a custom made circuit.
I'm planning on using a ESP-12E module board as the application will need to connect every once in a while to internet to gather data, acquire sensor data,... |
H: How to use 8 IR receives that when one of them sense IR turn on a LED?
I want to use 8 IR sensors (4 on front of vest, 2 on back and 2 on headband like lazertag vest) that when each of sensors hit by IR, turn on a led. I don't want to use any microcontroller so a simple circuit is what I want.
I can achieve this by... |
H: Axial capacitor terminal leads snapped!
Unfortunately, while in transport, my capacitor's terminal leads have snapped right to the bottom. What can I do? Can I solder something in their place, so it can work?
Many thanks.
AI: The lead was welded to the bottom of the aluminum can.
There's no easy good way to connect... |
H: Maximum Vpp that doesn't change the output offset
I have a homework problem:
We have a non-inverting amplifier, \$G=+20V/V\$, which amplifies a perfect square wave, \$\overline{V_{IN}}=0.5V, \ V_{PP}=0.05V, \ f=50kHz\$. The output signal has offset equal to \$\overline{V_{OUT}}=10V\$. We also know that the smalles... |
H: How to calculate voltage drop across multiple wire gauges?
This seems like a googleable question, but I simply cannot come across anything.
I'm working on a 12v system (aluminum boat), trying to supply power to a motor 12ft away from the circuit breaker. Through online sources, I was able to determine that at the ... |
H: Auto LED dimly lit when off
I bought an LED bulb, W5W, to replace the position lights, number plate lights and maybe the interior reading lamps. However they stay dimly lit when they're off.
I am thinking that the current is already flowing through the wires when the lights are off and the key is out.
So the circui... |
H: I'm planning to put lots of phone chargers on one circuit, how to calculate this
This would be primarily for samsung S7 devices. Would like to be able to charge, say, 256 of them.
They will work in groups of 16, trying to design the power flow of this. Was imagining that each group of 16 would plug into a USB pow... |
H: Mains Filter for Power Line Comunication
I have two questions about Mains filters and their impedance effect on PLC.
1) With respect to signal propagation relative to the Line impedance:
As the signal is sent, via the power line, it will take the path of least resistance. Therefore the line to the PSU needs to hav... |
H: What does this mosfet switch circuit do?
I found this piece of circuit in a battery powered sensor. It's a magnetic door sensor.
I am not able to figure out what does this do?
AI: It's battery reverse polarity protection like this circuit: -
When the battery is connected correctly, the PMOSFET turns on and acts l... |
H: Amplification of sinusoidal signal from filter circuit
Intention of the project is to obtain sinusoidal signal generator of frequency range 10Hz to 100Hz and 5v signal from microcontroller i.e arduino uno,
using pwm from arduino uno I got the square waves of 4.3v - 5v, the signal was fed into the RC low pass filte... |
H: Regarding Power Market demand and supply
As I have read, that power supply should be equal to demand. As it can't be stored .So basically this means power is generated in real time.
Consider an area where power comes from a Substation A, which receives power generated from power plant B.Of this area suppose each de... |
H: How to boost 12V DC to 24V DC?
I am trying to power an ultrasonic mist module, which works at 24V and requires a few milliAmps. I have a 12V DC power supply, how can I use it to power my ultrasonic module?
I searched on the internet and there are multiple(rather complex for a beginner) ways given to do so, is there... |
H: Can I replace these many capacitors with just one?
I'm designing a schematic for an addressable RGB LEDs array and I've chosen the WS2812B because of how common and cheap they are. Looking at the typical application circuit, I noticed there is a capacitor for each LED.
Can the multiple capacitors be replaced with... |
H: Loop Gain and Phase Margin Correlation
I have found a definition of phase margin of amplifier system from Texas Instruments application report. This definition looks like this:
$$\phi = tan^{-1} (A \beta)$$
where \$ A\$ is amplifiers open-loop gain (aka direct gain) and \$ \beta \$ is feedback return signal ratio -... |
H: Potentiometer/attenuator between amp and speaker
I have a setup where an amplifier with 2 channels drives four 8 ohms 80 watts speakers on each channel. The amplifier has a single volume knob which controls volume of both channels at once. What I would like to do is add a volume control for both channels separately... |
H: what is the function of the trigger coupling in an oscilloscope?
Could someone please explain to me what's the functionality of the trigger coupling in an oscilloscope (the difference between ac trigger coupling and the dc trigger coupling) ?
Thank you .
AI: Let's say you have a scope with an "intrinsic" sensitivit... |
H: What should I do to unused input parts/features (analog and digital input pins, and power pins) of a video scaler chip?
I am working on a video scaler chip which has multiple inputs (i.e HDMI, DP, VGA) but I only want to use the VGA input. (Choosing another chip with only one input is not an option).
The friendly d... |
H: Understanding atomic writes to GPIO on different ARM Cortex-M's
This video succinctly describes why the read/modify/store has potential problems when it comes to interrupts. Very clear and understandable.
He uses the TI Stelarris Cortex-M4 as a teaching board and in the minute I linked above describes how that ... |
H: What do we mean by "gate plateau voltage"?
While reading some semiconductors datasheets, I've found something called "gate plateau".
What do we mean by this term ?
Reference:
AND8029 application note page 2, from ON Semiconductor written by Christoph Basso.
AI: It's called a plateau because it's relatively flat, c... |
H: Defining a circular cutout in a pad in Altium
I'm creating the footprint for a Wurth inductor, 744043100. The recommended land pattern is below.
They use a radius 1.8 mm circle in the middle of the component to define a void in the pad. I'm trying to create the same shape in Altium, but am running into some trou... |
H: What is this three pin, cyclindrical component?
I'm curious as to what the component is on this PCB. It is surrounded by a polyfuse / zener arrangement (for overvolt / fusing) - I believe it is something to do with the AC input but am not completely sure. It appears to be polarized.
What is it and what might it be ... |
H: KiCAD 5 --- what is the significance of the various GND symbols?
I'm new to KiCAD. I see symbols for GND, GNDA (analog), GNDD (digital), GNDPWR, GNDREF, etc.
Is there any significance aside from "schematic documentation"?
I was expecting that maybe the reason for the multiple symbols is that the PCB layout tool ca... |
H: multiple RGB LEDs with common resistors for each color
I am modifying a pcb with 9 RGB LEDs having three resistors each normally. I know that it is the proper way of doing it. However what is the disadvantage of connecting them as below?
Resistors being higher power rated compared to three resistor each setup.
AI:... |
H: Bench Supply Amps - 4AA Batteries
I have a battery powered device that runs from 4 AA batteries. Whilst testing, I am wanting to power it from an adjustable bench power supply.
How can I work out what amperage to set my bench supply at? Do AA batteries have a standard amp rating? There is nothing mentioned on the b... |
H: Bit order of ADV7125 ADC
Datasheet: http://www.analog.com/media/en/technical-documentation/data-sheets/ADV7125.pdf
Assuming R0, G0 and B0 are the least significant bits of each channel, but cannot find it specified anywhere in the datasheet explicitly.
Is there a convention for this that the higher the bit number, ... |
H: What is the meaning of the "lasso loop" on circuit diagram?
I've never seen this "loop" structure in a circuit diagram before.
Pin 6 has a line that loops around the lines from pins 5 and 9.
Pin 7 has a line that loops around all other lines, except the ?resistor? between pins 1 and 6.
NOTE: This pinout diagram... |
H: First Order Filter - Voltage Follower Attenuation
I have a first order filter. It is supposed to have unity gain at frequencies below the 3dB frequency of 50Hz. I have simulated two of these first order RC filters. One where the signal is fed into a universal op-amp acting as a voltage follower and another as a sim... |
H: What is the miminum voltage for series NiMH pack?
Suppose a pack of 8 AA NiMH cells are serially attached and its known NiMH cells should not go below 900mV per cell.
Does this really mean the pack should not be discharged past 7.2v?
AI: Your sums are right, 900 mV * 8 = 7.2v.
However, what happens if the pack is u... |
H: Schematic indicator interpretation
I was attempting to get familiar with the Texas Instruments CDCE62002.
While checking the datasheet of the evaluation module, I came across the following indicator in the schematic. I'm curious about the dashed line which is visible. For a full view of the schematic please check ... |
H: Negative Edge Trigger and Asynchronous Clear not working in ModelSim
I have created a 4 bit counter with the following inputs and outputs
clockN: active low clock
clearN: active low clear
cP: When high, the counter counts. When low, the counter stays the same.
eP: Active high. This activates the tri-state buffer ... |
H: How to program SoC chips like CC2541F128RHAT
I am working on a BLE project. As per initial research, decided to use the cc2541 chip as BLE module. I have found one here. As per the datasheet, it shows it contains BLE and MCU. I need to program the MCU for accessing the GPIO pins. Can I connect a USB-TTL converter a... |
H: Intel max 10 dimensions - datasheet & BSDL mismatch
TL;DR: The BSD file from Intel doesn't match the datasheet. What are the right dimensions?
BSD: https://www.intel.com/content/dam/altera-www/global/en_US/others/support/devices/bsdl/10M02SCM153.bsd
Datasheet: https://www.intel.com/content/dam/www/programmable/us/e... |
H: What is the purpose of this two pin component?
What is the purpose of this two pin component (circled)?
It looks to me like a jumper, but it seems strange that it would be so complex for just a jumper (that apparently does nothing). Sits between an AC input and a bridge rectifier.
AI: It's a solderless spade connec... |
H: Altium Gerber File Copper Breaks
I'm getting some really weird effects on my Gerber File outputs from Altium
Altium 18.1.9, using OutJob Files, here are my settings
My layers look completely normal with a copper pour for the ground plane like shown here
However, when I export Gerber files, I get these bizarre ... |
H: How do I calculate the unknowns of the current equation for a RLC series circuit?
Suppose I was dealing with the following voltage equation for the RLC series circuit:
\$ v(t) = Ae^{m_1t} + Be^{m_2t} + V_s \$
To know the values of A and B I would do the two initial conditions:
voltage at t=0 (I would solve the eq... |
H: How do I connect up a replacement run capacitor
I have bought a replacement Run Capacitor for a forced action mixer (special cement mixer), as the run cap on the mixer blew. The mixer has a single phase motor, and although we are in the UK, it runs from a 110V power supply (standard on UK construction sites).
Possi... |
H: What is the typical value for thickness of via plating?
I use PCB tools and sometimes they ask for via plating thickness, what is a value that I can approximate most via plating thickness? What value would you use and why? If I wanted to bound the thickness (min,max) what values could I use?
AI: Standard Spec for B... |
H: Powerbank from laptop battery
So I just found an old netbook which battery has 6x 18650-26F cells and thought of trying to make a powerbank out of them. This is the specs page:
http://gamma.spb.ru/media/pdf/liion-lipolymer-lifepo4-akkumulyatory/ICR18650-26F.pdf
I just need some ICs and a bit of soldering to make t... |
H: How to read Capacitance Table?
I bought a 30pF Variable Trimmer Capacitor, but am unsure how to adjust it. The lowest capacitance I am getting by adjusting the screw is 50pf, and it doesn't seem to matter which way I turn it. I contacted the seller again to get more info about the range (I need 2-22pf for my fm tra... |
H: Need to find a compatible ac adapter
I have a Syemour Duncan guitar effects pedal that I bought several years back. I seem to have lost the power adapter for it and they don't make them anymore. I looked at the power input on the pedal and it says 16V~ / 560mA. The manual says
Do not try to substitute a DC power s... |
H: Which DC power jack to use with AC-AC adapter
I bought an AC-AC adapter for a project (takes 120 VAC mains and produces 12 VAC/3.5 A). It has a regular DC power jack (2.5mm I.D., 5.5mm O.D.) and I want to purchase a DC power jack to connect to it.
However, all DC power jacks I could find are rated for a specific DC... |
H: How do the Ripple Limit lines get determined on antenna measurements?
I'm doing an S21 ripple measurement through a VNA and I understand how the measurement is done, but I don't understand how the limit is determined. I know you can specify the limit in dB and then you specify the Hz where that limit applies.
Howev... |
H: Control large voltage supply using smaller voltage
I have a 6 volt supply that I need enable/disable using another 3 volt supply.
If I use a PNP Darlington set-up like this:
Then I get just under 6 volts at the Output node.
My problem is that I don't have any PNP transistors but I do have several NPN transistors a... |
H: How to create custom through hole pad shapes in Altium Designer?
I'm trying to create a footprint for the ACS770 current sensor in Altium Designer (17.1), which has a quite irregular shaped pad: ('round' pad shape with slot hole, and then a small cutoff in the middle). How do I generate such a pad shape?
This is wh... |
H: Problems extending a 12V power lead to an RGB-LED strip
I need advise on the following problem: I am connecting a 5 metres WS2812B based RGB-LED strip to an extension cord. This is a 12V version, where two LEDs are coupled in terms of their addressing and IC. There are 100 addresses and 200 LEDs. I am generating th... |
H: What equipment do I need to test an eye diagram for USB?
I'd like to test USB full speed with a goal of testing high speed (480 Mbit/s), I have a tek scope that does 300 MHz (which I could upgrade to 500 MHz) and I'm looking at a 500 MHz differential probe. As I understand it I also need a breakout board (which I'm... |
H: What is the "Nyquist" rate for sampling the derivative of a signal?
Background: I'm sampling the current through a capacitor. The signal of interest is the voltage across the capacitor. I will digitally integrate the current measurement to obtain the voltage.
Question: Given that the voltage across the capacitor i... |
H: Cheap way to get 5V DC from 12V AC?
I'm currently doing a home automation project which involves my intercom system being controlled by a NodeMCU. The intercom system runs off 12V AC. As for the actual automation/wiring itself, I think I have that fairly well covered. However, I would love to be able to power the N... |
H: Wiring for a 12V AC relay module?
I'm currently trying to automate my intercom system. My overall aim is to have it so that I can both detect when the buzzer has been pressed and then also to have it so I can open the door. I am using a NodeMCU as the main controller. I'm fairly familiar with DC but have had virtua... |
H: Alternatives to High Wattage Resistors? (Do multiple low-wattage resistors equal a single higher wattage resistor?)
I am a beginner, so I may have made a horrible mistake in my diagram, but I am trying to learn.
According as I have figured it, I am having an issue wherein I need a resistor rated for a minimum of ab... |
H: Finding the unknowns of a current equation leads to non-sense
Suppose a series RLC circuit that is critically damped.
Circuit is RLC in series with a DC voltage source \$ V_S \$ and a switch initially open. Capacitor and inductor are both discharged.
at t=0 the switch is closed.
I am trying to analyze what happens ... |
H: UL Clamping Voltage Ratings on Surge Protectors
I have been looking for some new surge protectors for my devices, and I am having trouble understanding the meaning of the voltage clamping ratings on many surge protectors. It seems that all of the UL ratings are much higher than one would expect, as the lowest one i... |
H: Power Supply - Shorting a cable creates a ground?
I used a power supply the other day to power an op-amp. I was told to set it up in the following configuration, however I do not completely understand why this works.
The shorted cable acts as ground??
AI: You can pick anything you want and call it ground.
This powe... |
H: Is group delay the same as the delay of a certain frequency?
I know that group delay is the delay of the envelope, or the derivative of the phase with respect to \$\omega\$. What I want to know is what exactly happens in the time domain.
For instance take the following graph of the group delay of a bessel filter (t... |
H: Can someone explain me the role of MOSFET in this circuit ? Are these MOSFET working as a switch here?
This Image is taken from the PIC16(L)F15356/75/76/85/86 MCU datasheet
datasheet- go to page number 286 for more details
AI: Your question is answered on page 28.
Because they are enable bits, yes, they are being... |
H: Explanation of the circuit in an LED bulb
I just know the basic electronics, not an expert in the area :)
When I dismantled a broken LED lamp, I could see the circuit below (section after the rectifier, the DC part). 15 LEDs in series. There are two such lines. If they were just parallel lines I know how the circui... |
H: Use USART pin in UART mode
I want to use a device who has an USART interface. But my microcontroller has only a UART communication.
Can I connect the UART_TX and UART_RX on USART_RX and USART_TX?
Thanks
AI: Yes you can if you use only asynchronous communication (ie. without separate clock line).
By definition an UA... |
H: Is there an "L" type of five wire connector?
With the controller shown,
notice the connector heads "west" (yellow),
meaning a tight enclosing cabinet needs to be as wide as the red indication.
However, if the white connector immediately did a 90 degree turn down
(direction downwards in blue)
you can see it would ... |
H: DAC negative bias reference voltage
I'm using TI's 18-bit DAC9881 and need the output to go a little below 0Volts in order to account for offset voltages of following Op-Amp stages.
The DAC allows to provide a "low reference" between -0.2V and 0.2V to offset the output, which is just what I need.
My question is how... |
H: Capacitor in common collector circuit
I have a question regarding \$C_1\$ capacitor - do we really need it in this circuit if we know, that the input signal will have no offset (i.e. \$\overline{V_{IN}}=0V\$)?
AI: do we really need it in this circuit if we know, that the input signal will have no offset
You mean, ... |
H: Tolerance on SMD Aluminum Electrolytic Capacitors
I'm searching for some polarized surface mount device capacitors on lcsc.com and notice that they only have tolerances of \$20\%\$ tolerance devices in their catalog for this type of SMD device whereas the through hole counter parts have much lower tolerances. Is th... |
H: What kind of breadboard and prototyping board do I need for this right-angle DB25 connector?
What kind of breadboard and prototyping board do I need to fit this right-angle DB25 connector?
I'm new to soldering and don't know what the standards are. Additional information on this subject would be helpful as well.
A... |
H: Fire danger when using IoT components
I am automating my house using components like ESP8266, 220 to 5V converters, relays etc.
How big is the risk of a fire starting from a component malfunction and how can I mitigate this? What should contain my design in order to minimize this risk?
Is there a book or some docu... |
H: Choosing inductor to limit inrush current
I have a 12V DC input to a circuit. There is a 660uF Aluminum cap on the input.
The 12 volt source is not in my control and can come from anywhere. So it could be a noisy source or a high current clean source.
I am wondering if it's worth it to put an inductor in series wit... |
H: Series RL AC circuit Laplace analysis
Question: Find the complete expression for i(t) in a series RL circuit with source \$Vsin(\omega t)\$.
simulate this circuit – Schematic created using CircuitLab
So to attack this I thought to bring out the ol' ant trusty Laplace tranform.
The final eqn I get is
\$ V \frac{\... |
H: FIFO Buffer (Circular/ring buffer) for packet storage
I am developing a simple radio transmission network using B-L072Z-LRWAN1 boards. The network structure is formed by:
One board acting as a gateway (where data is received).
Multiple boards acting as nodes (which send data to the gateway).
The packet payload se... |
H: How to set output voltage on this dual output buck converter board?
I guess this board's dual output voltage is configured by the EN terminal?
Resistance to ground? (Link to the eBay listing: 20W DC-DC Step UP & Down 5V-35V 12V 24V to ±5V ±9V ±12V ±15V Dual Power Supply.)
These are cheap on eBay, but I bet they arr... |
H: Is it better on two closely connected microcontrollers to send nibbles with an ack or a byte with a delay for an ack?
I'm trying to figure out the best approach to transfer high-speed data one way between two microcontrollers (with their own crystals of the same speed) of the same variety (between AT89C4051 and AT8... |
H: Hand-cranked vs hydro-turbine generator for single potential energy (no continuos flow)
Let's say you have a certain amount of water at a height; think a bucket with 3 liters of water in it on a 4 meters tall wall. By letting this water to fall, we'd have an opportunity to convert some of this potential energy into... |
H: How to read wire wrap labels?
This image is an example of a wire wrap label that lists multiple AWG numbers.
What does it mean? How could it be anything but a single specific gauge?
AI: The part number (P/N B-30-1000) indicates it is AWG30 (and black and 305m = 1000').
The part number is printed onto a pre-printe... |
H: Apply voltage to a solar cell
I was thinking about a power circuit in which the power can be supplied on the same rail through a solar panel or an ac adapter. I automatically thought to add diodes in series to form an OR gate, so the panel wont supply the ac adapter and vice versa. But then I thought- do I really n... |
H: Why does Channel Length Modulation Increase with Higher Vgs
I'm curious as to the physical reason as to why the effect of channel length modulation in an N-MOS actually increases when the Vgs voltage is increased?
See the plot below:
For a long channel device, as the Vg is increased, the R0 is actually decreasing.... |
H: How to rotate several parts with respect to origin without changing its (x,y) coordinates in KiCAD?
Say I have a part located at coordinates (50,50) and I want to rotate it 10 degrees w.r.t. origin. To do so, I will select the part and press "Move Exactly" and key in these values:
Now the problem is I have 50 sep... |
H: MCP73831: VBat Voltage drop with new uncharged batteries
I made a circuit for charging a 40mah lipo battery (381018), my problem appears when a new uncharged battery is connected. The battery measures 0V at the begining, when it's conected the VBAT pin only goes to 1.58V, so the battery is not getting charged at a... |
H: Why is resistor in parallel with capacitor needed in capacitor bank?
Capacitor bank in power supply compensates for when input voltage is shortly disconnected (50ms lets say). Do capacitors in this setup (between input and the output of power supply), get initially charged and then remain charged until input power ... |
H: How much voltage and current to charge a 24V battery?
If I have two 12V 18A batteries and I want to charge them in series making a 24V 18A battery, how much voltage and current do I need to charge this 24V without damaging the batteries?
AI: You need to get the voltage and current charge information for the batter... |
H: Identify the op amp IC
I am repairing a board, that has an IC labelled K72 J46 P.
I know it is an op amp MSOP8, and that pin 4 is GND, but I cannot find the manufacturer part number so that I can buy a replacement.
AI: It appears to be an NCV20072 or NCS20072, which is a 3MHz dual rail-to-rail output op-amp. Data... |
H: If I convert 10 V, 1 ampere to 5 V, do I get 5 V 2 ampere?
I know the current in the circuit is the same.
And also,
Power = 10* 1 = 10 watts.
So,
10 = 5 V * (x) ampere,
X = 10/5,
X = 2 ampere,
With some loss while using a voltage regulator, I will get some loss in current also ... That's not a problem. All I n... |
H: Using SFP modules from a microcontroller
I'm interested in having an embedded device send data optically. This is for test and measurement, where having conductive cables is problematic since it will perturb the measurement. The device is built as a prototype now except for the data sending interface. The data rat... |
H: What is PVDD and AVDD?
I know VDD,VCC,VEE and VSS and what they stand for. But when I came across this circuit:
I saw this. Those PVDD and AVDD terms?
What to do they convey or stand for?
This circuit is amplifier circuit of PAM8403 DS.
AI: The answer is right in the datasheet for PAM8403:
So P stands for "power"... |
H: Can really small transistors be modeled as in undergrad textbooks?
Most undergrad textbooks on microelectronics (those covering semiconductors, diodes, BJT's, FET's, etc.) that I have laid my hands on discuss semiconductor concepts such as charge carries, drift, recombination, among others, to explain why transisto... |
H: Electromagnetic wave equation for GPS waves
Recently, I came across a source which stated the model of a GPS L1 wave was:
My question is, how was this equation derived?
AI: That equation isn't derived, it describes the contents of a GPS signal that is created by the electronics in the transmitter in the GPS satell... |
H: Why is digital serial transmission used everywhere? i.e. SATA, PCIe, USB
While looking at SATA, PCIe, USB, SD UHS-II it struck me that they are all the same: digital serial bitstream, transmitted using differential pairs (usually 8b/10b coded), with some differences in link/protocol layers.
Why so? Why did this bec... |
H: 4th order (active) filter, I want constant phase shift band
I'm needing to improve an existing fourth order active filter design.
The filter amplifies 10-100 kHz signals as desired, however the phase shift is causing problems. 10 kHz signals are phase shifted around 200 degrees, but 100 kHz signals are phase shifte... |
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