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H: Pass USB 3.0 connection through D-SUB connector
I need to pass a USB cable through a vacuum chamber wall, for which we have only D-SUB passthrough flanges available. So I cut a USB cable in half and soldered a D-SUB connector to each half. For USB 2.0 connections, this works without any issues, but I've had trouble... |
H: I2C setting MCU as both slave and master at the same time
Hello everyone I'm working on a new project with the TI MSP432P401R microcontroller. I want to have 2 separate I2C buses. I2C bus 1 will set the MCU as the master, whereas the DAC and the pressure sensor as slaves. Then I2C bus 2 will set the same MCU as the... |
H: ADC Calibration - Vdd calculation
In documents and lots of online sources there is a formula as follows,
$$ Vdd = 3.3V * \frac{VREFINT_{CAL}}{VREFINT_{DATA}}$$
But I cannot get why CAL value is in the numerator and RAW data is in the denominator. I have this logic in my mind,
In the factory, producers used a prekn... |
H: Poles and Zeros of a Transfer Function
I am trying to understand the physical meaning of poles and zeros of a transfer function. Can someone help me how to understand the Figure 2b in the link below?
What does the height of the cone indicate? And what do the different color rings in the cone indicate?
The Link
TIA.... |
H: Voh value not provided
I have this EEPROM IC where I want to check the logic level compatibility with another IC.
But here Voh value is not given. I have observed this in my other IC also.
Why is the Voh value not provided? What shall I take as Voh?
Thanks
AI: This device uses an I2C interface so the SDA output is ... |
H: Headphone sensitivity/efficiency
Most commercial headphones are advertised to have sensitivity greater than 90 dB/mW. But to my understanding, even with 100% efficiency that's not possible (if we use 10 log (I/I0) where I = 1 mW, we get 90 dB). So, is this an exaggeration or am I missing something?
AI: You are mixi... |
H: What does it imply when substrate terminal of Nmosfet is short-circuited with the source terminal?
What does it imply when substrate terminal of N-MOSFET is short-circuited with the source terminal?
AI: Since this has the appearance of a "homework" question, I'm not going to provide a direct answer. Instead, I offe... |
H: Why this H-bridge with only N-channel FETs didn't work?
Based on this answer here in StackExchange and the Motorola article it cites, I've designed a dual h-bridge motor driver with push-pull transistors to switch the FETs faster, layed out a PCB in KiCad and built it.
The restrictions were to use only N-Channel F... |
H: Photodiode to an ADC
Please bear with me as I'm not too experienced with this.
I'm attempting to use an ADC to get readings from a photodiode. From what I understand, I should likely use an op-amp as the range of the current that will be provided by the photodiode is low (0-150 uA), and I can output a voltage requi... |
H: Timer Protection Circuit
I need to create a circuit that sends out a signal only if the input it on for longer than a specified time. Lets say 20 seconds for this example. So if the input to the circuit was pulled high for 10 seconds no output would be sent, but if the input was pulled high for 21 seconds an output... |
H: How to increase pcb trace width after fabrication
I am new to pcb design and my first designed pcb is burning, I have checked some traces and I found this:
C18 capacitance is 0.1uF and 100V rated. The problem is that slim trace width is only 0.2mm. So maybe this might cause some burning. is there any way to fix t... |
H: Increase emf received from a coil without changing flux source
I have a situation where I'm trying to increase the amount of power received by a coil. To my understanding, I can increase the emf (voltage) by doing one of 4 things:
Increase the number of coils (\$ N \$)
Increase the field from the source by increas... |
H: Requirements for PCIe Bifurcation on SBC
I'm looking for clarification on what actually needs to happen in order for a device to support PCIe bifurcation. Some forums say it's motherboard dependent, making me think it's not tied to the processor I choose, but all that is in the realm of PC hardware. My application ... |
H: How to power up a project with 3 devices, between 0 and 12 volts
I'm working on a project which involves a DC heating element, a computer fan and an Arduino/ESP8266. I'd like to use one power supply for those devices.....
The requirements:
The heater needs a steady 12V / 1A DC
The fan needs 0 - 12V to operate
The... |
H: What are some good replacement ICs for DIP UARTs?
Recently, I have been developing an SBC based on the Zilog Z80 microprocessor. Since my first design, a serial connection has been essential for the board to communicate with a PC or terminal. For this purpose, I have been using Zilog's own Z80 DART (or SIO/0) becau... |
H: (THEORY QUESTION) If a diode was not placed in a buck convertor, when the switch is off would the load still be powered on?
(For Theoretical Purposes and Understanding assume the diode is not in the circuit)
I just have a bit of confusion regarding the buck convertor when the switch is off. Since an inductor canno... |
H: DIY USB Power Hub
I'm looking to see if assembling my own USB hub is an option. I need to charge 20 devices via Micro USB at once. Data transfer is not needed.
Is anything stopping me from getting a 5V 20A power supply and wiring up 20 Micro USB cables in parallel? Does any protection circuitry need to be added?
T... |
H: Is it possible using two 3.3v LDOs from one SMPS AC-DC 5V to power 2 MCUs?
I'm planning to use two 3.3V LDOs to supply power for two MCUs, one is STM32, one is ESP-12. Input power of these two LDOs come from one SMPS module 5V, 3W (HLK-PM01). The reason for two seperate LDOs: I'm using STM32's ADC and I think separ... |
H: What is best sources for learning and practising AVR microcontrollers?
I am computers and systems engineering student and I am very interested in microcontrollers so What is best sources for learning and practising AVR microcontrollers ?
AI: That certainly depends on your previous knowledge.
Previous experience wi... |
H: Does Impedance Matching Imply any Practical RF Transmitter Must Waste >=50% of Energy?
According to the maximum power transfer theorem, when a fixed source impedance is given, the load impedance must be chosen to match to the source impedance to achieve maximum power transfer.
On the other hand, if the source imped... |
H: Impedance matching with complex impedance source
The method/steps to use a VNA to determine a matching network for a 50 Ohm (or whatever impedance) antenna seem mostly clear to me now. My current knowledge assumes though the transceiver (source) is basically the same impedance as the desired impedance (well, comple... |
H: What is a "mechanical pad"?
I've bought an FPC breakout stick from: Adafruit. In its datasheet, it mentions a "mechanical pad", which is the exposed copper bar near the connection pads. What does it do, and can I utilize it while soldering the FPC cable onto the board?
Here is the picture of the stick:
AI: The "mec... |
H: Confusion with RPM calculation of a DC fan from its datasheet
I want to calculate pulse periods from a tacho output of a DC fan. I want to read pulses by a MCU and convert them to RPM and display in LCD.
But I'm confused with the following description of RPM conversion from the manual:
It seems they mean I should... |
H: 100s of devices on SPI bus with daisy chaining - theoretically possible but who's done it?
I need to control 512 knobs digitally using 128 digital potentiometers. The AD5204 supports daisy-chaining but what do I need to be careful of when interfacing this with a ATmega328P?
I plan to split this across 8 chip select... |
H: RC differentiator giving a higher output amplitude than input amplitude
This is the circuit:
simulate this circuit – Schematic created using CircuitLab
And this is the output:
I am unable to understand the increase in output amplitude as compared to the input's amplitude. Mathematically it makes sense - rate of c... |
H: nodal analysis, current direction
Right, first the diagram, I tried using the schematic function,but it never actually added the schematic.
I picked this because it illustrates my confusion in the simplest schematic I could find.
We've got three nodes here, with the bottom (N3) being the ground node, current direc... |
H: Problem with NAND gate in proteus
I was doing a simple logic circuit in proteus when i realised that something was going wrong.
It looks like the NAND gate provides high voltage to its inputs from nowhere. No errors provided, but if i let the simulation running for a while, it always end with an unexpected close. ... |
H: BQ2057WSN Charging issues
I have designed a battery charging Module using BQ2057WSN IC to charge a 7.4V,6600mAH Li-ion battery. According to my calculation the charging current is set at 625mA.
The input power source to the Charging module (DC+) is 12VDC, 2A SMPS and the circuit is drawing 625mA from the Power sour... |
H: Spectral lines vs Envelope of PWM wave
On the wiki page of 'Duty Cycle' there is a nice animation that shows the frequency spectrum of PWM wave as its duty cycle is modulated from 0 to 100%.
The animation shows the 'spectral lines' as well as the 'envelope' of the spectrum.
What I understand is that the 'spectral l... |
H: Async SRAM Chip. Write Cycle. Data inputs timings
I'm working on my home project of building the 8-bit computer and now I'm on the RAM building stage.
I'm going to use this chip for as my RAM UTRON UT62256C (datasheet). This chip is to be connected to the common bus, to which 8-bit registers are connected through ... |
H: Quiescent current vs GND pin current for Linear Regulator IC power dissipation
I want to confirm that, for a linear regulator IC, quiescent current multiplied by the input voltage accounts for the IC power dissipation(including drop-out voltage loss).
I ask because the datasheets for some of the linear regulators ... |
H: Changing output voltage of a buck converter by electronically swapping the feedback resistors
I am going to design a circuit which is going to output some digital signals. The output stage of the circuit will have some level shifters. The level shifters will give flexibility to the user to choose the voltage level... |
H: Best way to connect balanced audio line to ADC (with volume pot)?
Sorry for this more longish question: I'm currently collecting some ideas for my next project where I want to connect an external balanced audio line level signal to an ADC with differential inputs (like a PCM1804, not specifically though). I'd also ... |
H: Can I combine water turbine without power loss?
I have this small 12V water turbine generator.
I connected one of these in a pipe running from a container on my roof to the ground. (height ~6m) and reached ~9V.
If I buy 6 and put them one after the other along the same pipe, will I have exactly the same amount of ... |
H: INA168 vs INA169 High-side current sensing
I have read the datasheets of the INA168 and the INA169 and can't see any difference, other than internal resistors value and quiscent current (25uA for INA168, 60uA for INA169). Those two were even made in pretty much the same period. Does anyone know if there is any dif... |
H: Suitable protection for elements on power line
I am working on mini project with 555 timer. The LED diode is not a diode, but a 12V LED string. What happens if there is a sudden drop in voltage?
Motor will induce voltage of opposite polarity. The diode in darlingon transistor will bypass that voltage to the power l... |
H: Converting Open-Drain to Active-High (low voltage, low power)
In my design, I need an RTC (PCF85263A) to enable a boost converter (TPS61021A) after the RTC alarm triggers an interrupt. The interrupt pin on the RTC (INTA) is open-drain, but the enable pin on the boost converter (EN) is active-high. This is a problem... |
H: Single GPIO for optocoupled input and output
I want to use a single GPIO pin as optocoupled input and output (at random discretion).
Will the following scheme work for any possible combination of input and output?
Especially when optocoupler 1 is open but GPIO output set to low?
AI: This could work, but whenever th... |
H: Through hole via isolation in Eagle CAD 4 layers board
In Eagle CAD, in a 4 layers board (signal-ground-power-signal) how do I avoid that a through hole via from, for example, the top signal layer to the power layer is electrically connected to the layer in between (ground)?
Do I need to manually move the ground po... |
H: Stable LDO voltage when Vin goes down momentarily
I have an application where Vin comes from a battery pack (3V - 7V) but on occasion and under heavy load, Vin drops to just above 2V for ~ 1 seconds before recovering.
There is a 3.3V LDO that provides power to the microcontroller. The LDO uses a pass transistor to ... |
H: Relationship between AWVALID and WVALID in AXI4-Lite interface
I am implementing an AXI4-Lite slave interface in FPGA and I want to have the read/write operations to complete in as few clock cycles as possible. With that in mind, can I assume any specific relationship between AWVALID and WVALID coming from the mast... |
H: How do I remove this power supply noise?
Above is the circuit diagram of my power supply. It converts input 12V DC into 5V DC and then 3.3V DC with linear regulator. I have highlighted it in red color in the block diagram.
So current situation is, whatever noise is there on 12V input voltage shows up on 5V and 3.... |
H: Flashing firmware onto NXP QN9020 via SEGGER J-Link
Here I am attempting to flash the firmware using SEGGER J-Flash Lite.
Below is the ouput when attempting to connect via the SEGGER J-Link Commander.
JLinkExe
SEGGER J-Link Commander V6.46j (Compiled Jul 12 2019 17:31:38)
DLL version V6.46j, compiled Jul 12 2019 ... |
H: How to see Signal frequency and Sampling frequency on the frequency spectrum
If I have a 100 Hz periodic analog signal and let us say it is band limited to 1kHz and I sample it at 3 kHz. If I want to see its frequency spectrum then how to differentiate between the signal frequency 100 Hz from the sampling frequency... |
H: Relay control by using microcontroller
I'm working on a I/O module to control AC, DC motor and lamps by using relays. But I don't know how to control the relays. Some says I should use optocoupler, some says transistor array.
I found an optocoupler TLP280, in the figure there is the schematic. Can I use it by supp... |
H: Why are MEMS in QFN packages?
I've seen that many (if not all of them) MEMS, like accelerometers, they are only available in QFN packages.
Why is that?
AI: Simply because: what else would you want to use?
Chip-scale packages are typically out: MEMS devices typically need reliable enclosure; a layer of lacquer typi... |
H: Understanding Responsivity of an IR sensor paired with a black body IR emitter
I'm building an air quality measurement system with the following components:
IR Dual Channel sensor by Pyreos
Axetris IR Balck Body emitter
Reading the sensor datasheet I've seen there's the Responsivity expressed as 150.000 V/W at 10... |
H: What would be the difference between the output of a power bank and a laptop usb port?
I have an encoder which I have been successfully using when powered from my a USB2.0 outlet on my laptop. I need to be able to run it whilst disconnected from the laptop and so tried powering it from a power bank. This is only in... |
H: Half Bridge with PWM- gate signal problem
After making a half bridge inverter using a square wave (I asked a question on this website about it previously) I have now decided to use PWM signal in order to obtain a sine wave output and have come across some new issues.
Here is the circuit on LTSpice:
The load is an ... |
H: VBE Multiplier with Emitter Resistance Cancellation
Function of shown circuit is biasing of output power stage complementary audio amplifier. P1 allows precise adjustment of \$ V_{CE} \$ of VBE multiplier and \$C_B\$ improves its rail rejection. \$ r_e' \$ negates unwanted effects of \$ r_e \$, also known as curren... |
H: Why are off grid solar setups only 12, 24, 48 VDC?
I am looking to produce 50kW for an off grid solar project. Ideally, I'd like to have a high voltage DC battery system with a high power battery inverter and charge controller.
I have only found a couple high VDC (384V) inverters and charge controllers, and they ar... |
H: Why do I need to convert impedance to admittance in this problem
1 = 18 A, 2 = 15 A , = 30 A and R2 = 4 Ω.
determine 1 and L .
This is the picture of the circuit:
And this my solution all the way to the point where I have uncertainties:
Now I can solve this in two ways:
I can solve it without converting impedan... |
H: Adding small AC signal to a DC current using inductive coupling
Is it possible to add a small AC current on to a DC current in a wire using inductive coupling from an external source. Or if there is another way, I want to add AC ripples to a DC current.
simulate this circuit – Schematic created using CircuitLab
AI... |
H: Why don't we worry about reverse recovery voltage and current of a diode in a simple circuit application?
When the diode goes into reverse recovery, why don't we worry about the power supply in that specific time since the current will be increased? Will it not damage the power supply or is it since it is happenin... |
H: How to set extra source and drain pins in PMOS power chip
I am using the FDS4685 chip here: https://www.onsemi.com/pub/Collateral/FDS4685-D.PDF
It has 4 drain and 3 source pins which I haven't seen before. I only need 1 source and 1 drain, how do I determine whether to connect these pins to ground or high to my 5V ... |
H: How to measure laser class of LIDAR
I just bought a LIDAR with the intention of building an indoors robot that uses it to navigate rooms in my apartment.
The manufacturer website states:
Low power infrared transmitter conforms to the Class 1 laser safety
standard and reaches the human eye safety level.
So, I we... |
H: For a MOSFET, does capacitive gate current only flow through to the source?
Everywhere states that a MOSFET has no current at the gate. However, this is not true since, during the time the gate capacitance charges up to reach the certain voltage threshold, the current is entering the gate capacitance.
My actual que... |
H: Barrier voltage and knee voltage are give same meaning?
Is there any difference between barrier voltage and knee voltage? Could somebody please let me know, if any.
AI: Barrier voltage is minimum amount of voltage required to conduct the diode , and Knee voltage is the same
Image Source : Quora |
H: How to control optocoupler and relay by using microcontroller
I have a question about controlling relays by using optocoupler. I have some optocouplers to isolate MCU's power and Power supply for the relays (to control LEDs, DC and AC drivers).
1) Can I control the relay according to the schematic below but withou... |
H: Does the LT Spice monte carlo simulation definitely output the max and min voltage for any number of simulation runs?
I have the following circuit, in which i need to calculate max and min voltages possible (considering resistor tolerance).
Does running a monte carlo simulation consider the absolute max and min v... |
H: How to run hair trimmer's motor normally (without pulsing) using 12V/1A charger? Its orignal cell battery uses 1.34V and 0.34A
I want to run a small DC motor (which is operated on a 1.2V 600 mAh cell battery) using 12V charger. Now the problem is that when I connect the motor to 12V, 5V, 3.3V the motor starts pulsi... |
H: Can I use the power from a computer to run my board?
I have an industrial PC which has some usb ports, and I want to use that port to get 5V and convert it to the 3.3V (with decoupling caps). But now I need to use that 5V to drive 12 relays on my board.
My question is that, Can I directly use that 5V, or should I ... |
H: Memory capability and powers of 2
Why are computer memory capabilities often multiples of a power of two, such as 2^10 = 1024 bytes?
I think it is something related to the binary logic, but I do not understand the precise reason for that.
AI: A 1024 x 1 memory chip requires 10 address lines and you get full utilisa... |
H: Replacing Sukam fusion 3.5kva Mosfet IRF2807
The mosfets on my Sukam Fusion 3.5kva inverter have blown, I want to replace them.
they have what looks like the following written on them
IRF2807
RP526Y
I can find IRF2807 but not IRF2807 RP526Y, would I need to replace the blown ones with the exact same mosfet?
P.S -... |
H: How to determine cross section of cable
I'm looking at this table that suggests a 0.5mm2 cable could withstand 720W at 3A.
At the same time I used a cable size calculator online to determine the size of cable I would need to use for a 12V60A which is also 720W and it gave me 8mm2 as the result.
And thinking about ... |
H: LTC6991 : unexpected ouput signal
I'm trying to make a 50% oscillator with a Tout=10ms period. Instead, I get a 5.7ms period signal, and an off pulse (low level) of 150µs !
I chose POL=0 and RESET is grounded. From table 1 of the datasheet, I pick the 2nd line : DIVCODE=1, NDIV=8, R1=1Meg, R2=100K. Vdd=3.3V, Vdiv=0... |
H: What does the minus sign mean in measurements in datasheet footprint drawings?
I have seen this more than once where there is a measurement such as "4-0.7". In this context, it clearly does not mean 4 to 0.7 mm so what does it mean. See the attached picture:
Link to datasheet: https://www.ckswitches.com/media/2780... |
H: Why does the max current capacity decrease with the number of cores for the same AWG?
I couldn’t find a similar or duplicate question yet but regarding this table for instance a 24 AWG wire can carry max 3.5A current if it is single core. But if it is seven core it can only carry max 1.4A.
Am I interpreting the inf... |
H: LDO voltage regulator, no output
I'm making my own board based on Arduino. To power it I use one LIR2032 cell (button cell 3.6V li-ion battery) that's driven through 3.3V LDO voltage regulator. So far I have tried two different regulators:
MIC5504-3.3YM5-TR
LD59015C33R
and none of them worked, both did not give a... |
H: Clamp a D/A to prevent output below 0V
I am using a USB D/A converter to drive a high-voltage op-amp with a signal between 0 and 3V at 10 kHz. The D/A I am using is capable of outputting between -10 and +10 and unfortunately seems to always output a 1 ms long glitch of -10.7V around 20-30 ms before the signal gener... |
H: Bare minimum pins for VME64 Bus
I have a board on which core for VME64 bus is implemented and it communicates with other boards on VME64 bus using only 1 connector (P1, 5 rows, 32 pins on each row, total 160 pins) instead of 2 connectors (P1 and P2). I am trying to understand its working in both Bus controller and ... |
H: Use a dropping resistor or a zener diode?
I have a situation where I need to power an Arduino Uno R3 from a ~16V power supply.
The problem is I have no idea of the implications of voltage dropping. I think I just need a 100 Ohm resistor.
So, in case I am right, my actual question turns into: When is it better to co... |
H: Common Mode Choke question
I have one question which I encountered during usage of common mode choke.
Question : "If a common mode choke is used on the main power / ground input, ensure that no I/O circuits effectively bypass the ground side of the common mode choke. For example, the shield of screened cables or ... |
H: Validity of AWADDR once AWREADY is asserted in AXI4-Lite interface
This question is a follow-up to Relationship between AWVALID and WVALID in AXI4-Lite interface, from which I learned that AWVALID and WVALID have no specific timing relationship.
Now I have a slightly different question. If AWREADY is asserted in re... |
H: Question about differential signals and feedback
Let's consider, for example, this circuit:
During lessons, our professor always assumed perfect differential input (two signals with the same dc value and with equal and opposite amplitudes). As a consequence node 1 will be an ac ground due to symmetry and the small... |
H: Building a byte-addressable memory
I am building a memory module:
32 bits wide,
parallel, and,
byte-addressable.
I did a research and i could not find an memory IC that will suit my needs.
It must be able to:
StoreWord,
StoreHalf and,
StoreByte (RISC-V), with or without an offset.
One suggestion was to b... |
H: MOSFET voltage drop and LED flickering
I've build a LED strip controller using NodeMCU and a transistor STP16NF06FP according to the schematic below:
LEDs were powered with 24 V power supply and I want to regulate it by changing the voltage using PWM on mcu. So for the simplicity's sake I output 255 on PWM pin D5 ... |
H: Pins for VME64 Bus arbitration
I have a board that has VME64 core implemented in it and this board communicates with other boards via VME64 bus. All boards share the same backplane motherboard which has J1, J2 connectors on it.
If the following pins on the board are connected as follows:
BG0IN is directly connected... |
H: KiCad where is the priority setting of filled zones?
The documentation shows a dialog for filled zones in which you can set up the priority of the zone.
I'm using KiCad 5.1.2 and I can't find this setting anywhere. Here's a screenshot of the filled zone dialog with 5.1.2:
It seems that the documentation is from 20... |
H: Finite State Machine and Reset Signal
let's consider a certain finite state machine, for instance a Mealy Machine:
I was told that it cannot work properly in absence of a reset signal (for the State Register), since we would not know the initial state of the device at the moment in which it is switched on.
But I ... |
H: How to simulate simple on/off, Single-Pole-Single-Throw switch?
I am trying to simulate ON, OFF switch in this simple circuit:
V1 0 1 1.5v
Rfan1 3 4 1
S1 1 4 SW ON
Rwire1 6 5 0.00001
VV1 0 2 dc 0
VRfan1 3 5 dc 0
VRwire1 2 6 dc 0
.dc V1 1.5 1.5 1
.print dc i(VV1) i(VRfan1) i(VRwire1)
.end
but I got this error:
... |
H: SystemVerilog FSM not working correctly
So, I was trying to create an FSM for my module which supposed to control five sensors. I thought I did it, but when I synthesized it, I saw that the code is synthesized as bunch of buffers and nothing else.
I think I do not understand what FSM can or can't do but I really co... |
H: If you wire together two TTL outputs, which one wins?
If you connect together two outputs from 7400 NAND gates, which output will dominate - high or low?
Background: I'm reverse-engineering a 1969 circuit board, and in multiple cases they tie together two outputs from 7400 NAND gates, presumably to make a wired-OR.... |
H: Moving Door on Electrical Box Alters Signal
I have an experimental setup that I am building to, among other things, measure the flow rate of water through a tube. The flow rate is measured by a sensor that is powered by a 24 VDC source and provides a 4-20 mA DC signal. I am currently seeing an interesting issue whe... |
H: What is this schematic symbol? Transistor ? Variable Inductor
I was looking through an old schematic and found two symbols that I didn't recognize:
Is this a PNP transistor? looking up the model number doesn't give much information.
Is this some kind of variable resistor or variable inductor?
AI: Is this a PN... |
H: How does an accelerometer interpret g as ( +9.8 or -9.8 )
I am working with MPU6050 (accelerometer + gyroscope). Concerning about the accelerometer;
Do these sensors(accelerometers in general) uses g as 9.8 m/s^2 or - 9.8 m/s^2 ? (Is there a standard/convention about this)
When I accelerate it in +x direction for e... |
H: Negative Feedback Factor
As of now most of the negative feedback systems I have encountered have a feedback factor that is less than 1 but positive. However in some situations it seems the system can behave as positive feedback if the feedback factor is not negative.. I just don't seem to comprehend how this negati... |
H: Rotary switch to turn LEDs on cumulatively
Problem:
I have a 12 position rotary switch and 11 LEDs that I want to switch on one after the other until they are all on (on pos 12).
Limitations:
It would be easy to use a μC, but I wanted to keep this simple and the part count as low as possible
Things I tried:
In my h... |
H: Data Lines on VME64 Bus
I am learning about the VME64 bus. It has only 16-bits of data bus on its P1 connector while no data pins on P2 connector.
Does it means that VME64 is actually a 16-bit bus?
AI: Not sure where you took this information from...
Connector P2 has additional address pins A24...A31 and additional... |
H: 555 timer that does not output low when reset
I'm trying to design a circuit with the following goals:
When not active, output can be either Vcc or floating
When triggered by pressing a button, output pulses several times to GND at some frequency F for a duration of N seconds
After the N second duration, the pulsi... |
H: Why/when is AC-DC-AC conversion superior to direct AC-AC conversion?
I am currently studying wind power and the power electronics used for it. In wind power a generator is driven by wind, thus the resulting power is of widely varying frequency and amplitude. The power grid, in turn, has strict requirements for the ... |
H: Unable to access the module error while trying to simulate a simple PLC Lad program
I am learning PLC and trying to simulate a simple program on Schematic Manager. But I'm having this error that says Unable to access the module CPU314c-2DP via the online interface. How can I solve it?
AI: One "trick" that often wor... |
H: uC-adjustable harmonic oscillator circuit @100W
I'm looking for a circuit that performs a harmonic oscillation while its resonance frequency can be controlled with a microcontroller (preferably via an analog signal). The circuit has to drive a set of ultrasonic transducers with a maximum power of 100 W at ~ 50 V an... |
H: Why can't I get correct reactive and real power in what seems to be easy task
As the title says Why can't I get correct real and reactive power
The task says:
Source with voltage \$U = 100\angle{30} \$ is plugged on to impedance \$ Z = 3 + 4j \$. Determine real, reactive and apparent power.
what I did was:
I fi... |
H: Negative Voltage Output From Capacitor
Circuit Link
I am very confused about negative voltage in capacitor, it can even light a led as you can see in the circuit.
My questions are;
1-Why capacitor gives ~-2 V in its negative terminal when we tie its positive terminal to ground?
2-How can that LED work by connecting... |
H: stm32f103 ADC strange behaviour
I am using stm32f103c8t6 discovery board and I was doing a practise by using ADC peripherals. While using keil debugger I have realized something so strange to me.If discovery board is not connected to voltage source or ground, It is giving like 1900-2200.
The adc is configured as 12... |
H: LTC3112: Limited Output Current
So for the past couple of days, I was testing out the LTC3112 Buck-Boost IC from Linear Tech. I'm using this for my heated glove project to step up/step down the voltage across the heating element. Using the typical application schematic for my test schematic with a 5V input (while c... |
H: Mosfet on or off
When do we say that a nMOS or pMOS is "on" or "off"? Are there any voltages across terminals we should be looking for?
AI: For MOS, the voltage from gate to source, Vgs, controls if it is on or off. PMOS turns on when gate is lower than source by the threshold voltage, Vgs(th).
Let's say Vgs(th) = ... |
H: What is the purpose of the optocoupler in this circuit to drive the mosfet/relay?
I'm currently trying to understand a circuit for an ESP8266 relay board. As you can see in the schematics below, an optocoupler is used to drive the relay mosfet. I do not understand, why they are using an optocoupler for the control ... |
H: Mosfet Threshold Voltage
from MOS theory we know that, in case of a P substrate, a Gate-Bulk voltage higher than a certain threshold value creates an inversion layer, in this case made of negative charges. This is also described in wikipedia (https://en.m.wikipedia.org/wiki/MOSFET).
But we always consider as thresh... |
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