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H: Antenna's resistance: meaning and evaluation
When I studied elementary antenna's theory, I saw that the resistance (for simplicity let's consider only the resistive terms) of an antenna Ra is made of:
1) a parasitic resistance Rl, which causes antenna losses.
2) a radiation resistance Rr which is in practice the fr... |
H: Protection circuitry for AC/DC converter
I'm using the RAC02-GB (Datasheet) as an AC/DC converter and I'm confused about the protection circuit they included in the datasheet:
I want to make sure the AC/DC converter has the proper external protections but I'm a bit baffled by the datasheet's directions. I'm assumi... |
H: Allwinner H3 TFT LCD display 40 pins
So I want to modify this board in order to add a 40 pins tft connector to drive a 5" LCD 800x480 display so the user can "flip" between HDMI and TFT. I have no idea where to start, could you give me a clue?
AI: You can't. (At least, not without ugly workarounds like adding an HD... |
H: What is the lowest voltage that a microcontroller can successfully read on the analog pin?
I'm testing the Seeeduino v4.2 board with the ADCInOutSerial code in the Arduino IDE and the lowest voltage the board can read is 18 mV, showing an equivalent ADC of 4 on the serial monitor.
The chip that the board uses is th... |
H: Why does reverse supply polarity damage the ICs?
Assuming you need for example an OR gate for your circuit project, you can use a 4071 IC or simply use two transistors as shown below:
But I wonder why the ICs are very sensitive to reverse supply polarity (as any other IC) but the transistor version circuit is not... |
H: Unknown equation in the SPICE resistor model
I was looking for simple resistor spice model, and came across this:
parameters
+rsh = 40 dw = 0 dl = 0
+tc1 = 0 tc2 = 0 pvc1 = 0
+pvc2 = 0 pvc3 = 0
...
+te... |
H: Power a 12V Solenoid and a RPi Zero with the Same Wall Socket
I'm building this circuit using an RPi Zero and this 12V solenoid.
I would like to be able to power the RPi and the solenoid from the same wall socket using a single power supply. For example, I've been using a 5V 2.5A switching power supply to power the... |
H: What happens when you assign the result of a reduction operator to a multi-bit wire?
I may just be having a mental breakdown, but what should be the value of f after the following:
wire [3:0] u = 4'b0101;
wire [3:0] f = |u;
Should this not create an error? What am I missing?
AI: After simulating in Vivado,... |
H: Voltage controlled connection of two signals that are at higher voltage than the control voltage
Given are two signals A and B. I want to control the connection between them by a signal C. However, signal C is a logic signal with a voltage of 3.3V for high and 0V for low whereas signals A and B are at a level of 4V... |
H: Is there a meaning of stripes on RS485, Phone and Ethernet cable?
I recently bought some RS485 cable, it had two pairs, both had stripes. One was mostly blue with a white stripe and the other was white with a blue stripe.
I'm mostly used to ethernet with a pair consisting of completely solid and white with a strip... |
H: How does this circuit start up?
I'm trying to understand how CI HT7A6322 starts up.
Relevant part of the datasheet says:
Control circuit power supply. Also provides a charging current during start
up due to a high voltage current source connected to SW. For this purpose,
a hysteresis comparator monitors the VC... |
H: Constant current LED driver using opamp
I'm trying to design a constant current LED driver and am totally confused!
This is the schematic i end up with:
simulate this circuit – Schematic created using CircuitLab
What's the formula for calculating R1?
What's the formula to calculate the required low-pass filter
c... |
H: Need smaller pullups on i2c lines, but design is low power, what is best?
The pullups on my i2c lines are 4.7k. People are afraid of draining the battery by fixing this waveform with smaller pullups, like 2.2k. It doesn't seem much power is wasted considering the short duration of the bus being low (2-4 byte trans... |
H: How to power a device using a USB port instead of AA batteries?
I have a device that uses 3 AA batteries and I would like to power it from a USB port instead.
As I understand I will have to use resistors but I have no idea on which ones.
I have found the following calculator: Voltage Divider Calculator
While it doe... |
H: Do I need to recertify a product if I add a DC to DC converter?
I have a product that has been FCC verified as an unintentional radiator, I have fixed a problem with the power that required a DC to DC converter that operates in the 100kHz to 300kHz range (added to the product). Would I need to get re-certified? Why... |
H: ICSP (pickit2) on 3.3v dsPIC33
I'm using a dsPIC33FJ64MC202 (@3.3V) for some project. I normally program my PIC projects with MPLABX through a PICkit 2, but I never tried using it on a 3.3V chip. Will it work?
I know the target Vdd value can be adjusted but, based on the programmer's schematics (datasheet, appendix... |
H: SPI signals show overshoot and ringing - does that affect reliability?
Here is MISO in yellow and MOSI in purple. I thought I would use a ferrite bead in series of each signal to filter out the noise.
I will be making hundreds of these boards. I'm not sure it is worth fixing, but I wanted these boards to be reliab... |
H: Are electrical properties measured using the International system of units (SI)?
What measurement system is used to measure electrical properties such as voltage, current, etc.?
I understand the units are defined by SI (at least according to this article), but is that considered the measurement system used to measu... |
H: Does increasing voltage increase the torque of a brushless motor?
1.) I have a brushless motor with testing data at 12V. I want to know if I increase the voltage supply, will this increase the torque?
In my research I keep seeing "current controls torque, and voltage controls speed." But that doesn't seem quite ri... |
H: Reducing power draw from appliance
I have an appliance (electric skillet) that draws 1500W when plugged into a regular (120V) household circuit.
If I want to be able to use it on an inverter that can supply max 1000W@120V, can I build a device with a transformer to limit the current drawn from the appliance to 1000... |
H: Disturbance Rejection in a Closed Loop Control System
I was reading an article about disturbance rejection of closed loop control system and I came across the sentence "becomes almost zero, and the effect of the disturbance is suppressed."
I have also attached snapshot of article and highlighted the confusing part... |
H: How to convert capacitor impedance to ESR?
I select an output capacitor for a DC / DC converter (LM2596), it is said that it needs a high ESR (50-60mOhm). In the characteristics of electrolytic capacitors there is no given value, but there is impedance. How can I get ESR from impedance?
I'm considering the YXF seri... |
H: 230VAC line voltage sensing using MCU pin
I Am designing a circuit to detect the presence of AC line voltage.It is basically to detect the switch On/OFF for a load.
Here is the circuit.
Here Input resistor ladder to step down the voltage. Varistor added to get it away from surge (Fuse included). zener to protect t... |
H: Side-channel leakage and instruction types on microcontrollers
Since the end of 90s, it is known that side-channels (e.g. execution time, power consumption, electromagnetic emanations) of computation platforms can be analysed to recover information on data being manipulated (e.g. keys in cryptographic calculations)... |
H: Convert select / trigger coils to direct fire
Working on ignition system controlled by prehistoric ECU, it has 2 signals: select and trigger. Select switches CoilA and CoilB. Trigger controls dwell time.
I want to purge old broken coils and install modern ones with integrated ignitors. So need to convert select/tri... |
H: What happens to the torque/speed curve of a brushless motor when I increase the voltage?
Here is a an image of the torque/speed curve. My guess is that increasing voltage will simply translate the curve up because the slope is the torque constant, which is a physical motor property that will not change with added v... |
H: On interpreting this set of curves (Transistor in Saturation mode and decrease of \$h_{FE}\$)
The following figure was excerpted from Horowitz's The Art of Electronics, Appendix G: Transistor Saturation (page 1089 for the 2nd edition),
It represents the current gain \$\beta\$ of an npn transistor ( or \$h_{FE}\$)... |
H: TFT RGB LCD construction and
I am trying to understand the construction of an RGB TFT LCD that has brightness control in it.
I could not understand how does the TFT color LCD pixels glow? Does each of the pixel has its own light that it emits just like an LED or is it that there is a backlight bulb behind the TFT L... |
H: op amp non-inverting input isn't working?
simulate this circuit – Schematic created using CircuitLab
Why in above schematic if i left the non-inverting input floating or connected to 1V or 3.3V the LED stays ON and current doesn't change with increasing/decreasing the Vref voltage?
Also LED current increases with ... |
H: Capacitor Negative Current Flow
I have a basic quesiton about circuit theory in general.
Consider the following circuit:
I understand that the resistor will have a constant voltage of 1V across it as it takes the DC component of the input voltage source. The capacitor will take the AC part of the input voltage sou... |
H: Filter before or after switching regulator?
I will be passing a power line (12V-60Vdc depending on the circumstance) with a lot of noise, 300Hz and above, riding on it through a buck regulator. I want to remove this noise with a filter. I don't know whether to place the filter before or after the regulator.
The cho... |
H: Window comparator diode direction
What happens if we reverse the configuration of diode in window comparator? Will it remain a window comparator?
AI: It won't work at all in this case. The output of the opamp goes high, and the diodes turn on when the output goes high. The diodes are in an "or" configuration allowi... |
H: Driving a TC4428 using PC817
I want to drive a mosfet using a mosfet-driver (TC4428). The frequency of turning on-off of mosfet is 5-10 Hz (yes Hz) and duty cycle is 10-20%. I use PC817 as below to make isolation:
As you see, if FLASH1 STROBE be 4.8 volts, voltage of collector will be 0.18 volt. FLASH1 STROBE come... |
H: What the R value to this operational amplifier isn't saturated?
In the following circuit, the three ideal operational amplifiers are polarized such that their saturation voltages are ± 20 VDC. The other components of the circuit are resistors, one of them being adjustable (the Rx).
What is the limit condition for ... |
H: What does an U244B IC’s input voltage do?
I’m new to electronics and I’m trying to connect a U244B ic on a breadboard. One pin says it’s an input voltage (pin 7). It works without anything being connected to the input and with battery connected to the supply voltage (pin 8).
What is it supposed to do?
https://www.... |
H: Can a DC brushless motor produce the same torque at different power levels?
I am looking these Neo Brushless motors for a project. Here are the links to the data sheet and also to stall testing from the company:
http://www.revrobotics.com/neo-brushless-motor-locked-rotor-testing/
http://www.revrobotics.com/content/... |
H: Can I use individual strands in cat5 or cat6 solid core wire for pcb mods / jumper / repairs?
I have a small PCB repair I need to make. I am reading that wire-warp is a suitable option. I don't have any wire wrap, but I do have tons of cat5 and cat6 solid core wire. I was thinking about gutting one of those and usi... |
H: Do I really need to learn how to use registers - Programming a microcontroller?
I have a curious question. Do I really need to learn how to use registers when I program a microcontroller?
I have been using Arduino for a long time. I quit using Arduino and starting to use STM32 because they are more cheap, faster an... |
H: Arduino lack of accuracy in AD conversion
let's consider this simple piece of code:
void setup() {
Serial.begin (9600);
}
void loop() {
int code = analogRead (A2);
double voltage = code *5/1024;
Serial.print("Voltage is ");
Serial.println(voltage);
delay (500);
}
It is... |
H: Components calculations for this circuit. Is my reasoning right?
In order to review some concepts, I decided to solve the circuit below that I found. It looks like a homework, but actually it's something I'm doing by my own. Below the circuit you can check my calculations and correct me if I'm wrong.
This is the st... |
H: Generate accurate 20mV Vref
I want to generate 20mV Vref using Op amp, like this:
When simulate with TINA using model from TI, instead of 20mV at output (Vref port), i see that it is 27.95mV.
My question is:
Why I can't get 20mV at Vref
How to improve this circuit to have accurate 20mV (+/- 5%)
Any recommendation... |
H: Load cells in Wheatstone bridge to produce logic signal
The goal is to use 4 units of 50kg load cells in Wheatstone bridge to act as a load detector. It should output a logic 0 or 1 if the load is greater than a threshold value. A MCU will read the states of 100 load detectors through a series of PISO shift registe... |
H: Understanding of a W65C02 micro computer
I found a tutorial with a schematic where you can buy a PCB for an old computer with a 6502 microprocessor.
I want to do this on my own with my own PCB (but I test the circuit on my breadboard first) and I have some questions for a better understanding of the design and thi... |
H: Op-Amp unusual symbol
I find this circuit in an old book.
Regardless what is the task of this circuit, i wonder why the op amp symbol is unusual(curved)?
This is the datasheet of LM301A: http://www.utm.edu/staff/leeb/LM301.pdf
But the other circuit in the same book using the traditional symbol for the op amp
AI: I... |
H: Is there any relation/leak between two sections of LM358 op-amp?
I want to use section A of an LM358 OpAmp to limit the current and section B to convert Arduino PWM to analog, and then connect output B to non-inverting input of input A as reference voltage.
The LM358 VCC is not going to be lower than 12V or higher ... |
H: Represent the given signal in mathematical form
Is this the mathematical form? I highy doubt myself
$$
-2r(t+3)+2r(t)+16u(t)-r(t)-2u(t-3)+5/2r(t-3)-5/2r(t-5)
$$
AI: Let the horizontal axis by time t and vertical axis by signal value x(t).
From t=-3 to t=3 the first part you wrote
$$ x(t) = -2 r(t+3) + 2 r(t) + 16... |
H: Calculate Vth between A and B
simulate this circuit – Schematic created using CircuitLab
In this circuit, I am asked to calculate Thevenin Voltage Vth between A and B.
This is the first time I am asked to calculate Vth between two distant point and I am not sure how to proceed.
AI: In other words, you are asked t... |
H: Plastic platform for THT electrolytic capacitor?
SMD capacitor looks like this
I did not see "plastic platform" to be sold separately.
But I want such to put under THT capacitor
so that it looks like exactly the way as quarts crystal with the gasket
I just like the way it looks, mechanically holds the the elect... |
H: flyback diode across the relay coil
so my question is regarding the diode used across the relay coil.
My A level textbook (the section from the textbook is given below) says that its purpose is to protect the op-amp from a back emf induced when the current in the coil is switched off. But this explanation is not ad... |
H: Using MOSFET to turn off the circuit
Usually MOSFETs stay in switched-off state by default and get switched on by a signal. But I want to use MOSFET the opposite way:
1) it should pull down a line to GND all the time by default, after power supply is ON
2) if needed, should be turned-off by signal from MCU, so tha... |
H: Coax characteristic impedance measurement
How is physically possible to get the value of the characteristic impedance of a certain coaxial cable?
Precisely, in my case I have a coax of 50Ohm impedance, and I need to cut it and connect some alligator clips or some tester leads. Now I thought that this variation mayb... |
H: How to check if my quadrature encoder is broken or not?
I have purchased some cheap quadrature incremental encoders (YUMO E6A2-CW3C) for which I have found "a" data-sheet here. Now based on my limited knowledge the quadrature incremental encoders are conceptually two switches. on the encoder itself, there is a colo... |
H: Invert or turn Aux Signal mono using Rotary Switch
Is it possible to use a 3 Pole 4 Position rotary Switch to do the following on the respective positions:
Send the Aux signal through normally
Invert Left and Right
Send the Left Signal to both outputs
Send the Right Signal to both outputs
Please excuse the crude ... |
H: Is a PWM required for regenerative braking on a DC Motor?
The DC Motor is question is here: DC Motor
I was wondering if you use a diode and a switch in a manner shown in the below picture if the motor would exhibit regenerative braking when SW1 is open? (Assuming that the voltage from the motor when braking exceeds... |
H: Parallel transformer output not expected RMS value
I have a 115V/230V transformer with specifications of: outputs 10V (parallel)/20V (series) and 1.2A (parallel)/600mA (series). Product
I'm no electrical engineer, but I need to get this set up to power my first hobbyist project. The reason for purchasing this parti... |
H: Fixing an old radio
I am trying to fix an old radio that my girlfriend just bought. It's from around 1964. I'm just a normal electrician and I am not used to fixing things like this.
Radio model: Huldra 7-45 Skapmodell
Is there anything I should keep in mind before powering it up for the first time. In my experienc... |
H: How to power a nickel chromium wire to produce heat without burning the power adpapter
I want to build a toaster just for fun. I want to buy a nickel chromium wire to heat the toaster's plate. How to avoid burning my power adapter cuz the resistance is too low. I currently have a variable power adapter that goes fr... |
H: Trying to simplify a Boolean expression
Simplify the following expression using Boolean Algebra:
$$ x = \bar{A} \bar{B} \bar{C} + \bar{A}BC + ABC + A \bar{B} \bar{C} + A \bar{B} C $$
Answer:
\begin{align*}
x &= \bar{A} \bar{B} \bar{C} + \bar{A}BC + ABC + A \bar{B} ( \bar{C} + C ) \\
x &= \bar{A} \bar{B} \bar{C} ... |
H: Resistor placement for Zener diode for over voltage protection
I have searched in over voltage protection (like MOSFET.) I wanted to use a Zener diode in parallel so it won't dissipate power unless in over voltage protection, but its power is low so I read that I need a resistor to control the current passing throu... |
H: Will the capacitor stop receiving more voltage when max is reached
I'm trying to understand how capacitors acts in different situations.
Let say i have a constant power input source that is rated 5v and my capacitor that is 100uf 25v is receiving this voltage.
If the power input is always running and the capacitor... |
H: Problems with DRV103 PWM
I've been doing some work lately with the DRV103 IC by Texas Instruments (datasheet here, essentially it creates a PWM signal of variable duty cycle and frequency, preceded by an 'ON' signal of variable time), which is a pretty cool chip, but I've hit a snag with it.
For a particular appli... |
H: How do I Avoid Very Long Horizontal Signal Path "Snakes" in a Schematic?
I'm drawing a schematic for my DIY project, a RF mixer, it has a local oscillator followed by a bandpass filter, a voltage divider, eventually the signal is fed into a mixer.
Unfortunately, even before I manage to finish the LO port, the signa... |
H: How to keep PWM from "contaminating" analog read values on my pcb
So I'm designing a PCB for a MIDI controller with a lot of slide potentiometers and push buttons. I'm also backlighting the pushbuttons with LEDs running on PWM and I'm worried that the PWM for the LEDs is going to create a lot of noise in the analog... |
H: Confusion with interpreting this power supply's power ratings
This 24V 150W power supply below is marked by the following ratings on its surface:
I use it for 200-240VAC and it is not clear to me how to interpret these values.
The AC input range is given as 200-240VAC.
The max AC current drawn is given as 1.8A.
Th... |
H: The TI quad-XOR gate acts as it is short circuit
I have a TEXAS INSTRUMENTS CD4030BE Quad Exclusive-OR gate. I have an electronic board of
simulate this circuit – Schematic created using CircuitLab
using this and this refrence. According to the XOR data-sheet:
I should have A ⊕ B ... |
H: LM324 - Issue with output in negative feedback
In my analogue output circuit, the following ripple voltage occurs when wired to the analogue input of a PLC with an input resistance of 69.3 kΩ.
If I put a resistor in series, this ripple disappears.
Why is that? Is it an impedance problem?
The schematic of the circu... |
H: Why does a IR Transmitter need a VCC?
I'm building a IR hub to control several LEDs stripes, and a projector in a room and noticed that my IR transmitter works even when VCC is not connected.
Should I wire it in anyways? Why is it there? What does it do?
This is the IR transmitter I have.
AI: Ideally, the IR-led is... |
H: Stiff, shape-retaining insulated wires vs "floppy" ones which "bounce back" - are there actual technical terms for those two types?
Pretty much what the questions says. I find myself in need of some wires and I want to get the "floppy" ones, but I realised I don't know what the actual technical term for it is and s... |
H: Comparison of the SOAs of two MOSFETs
Below the SOA for the IXFP6N120P:
And the SOA for the IRFBG30:
The first one shows a DC line beyond 100 ms, but the second one does not. Does this mean the second one is unreliable beyond 10 ms, or the manufacturer decided not to put a DC line assuming the area beyond 10 ms i... |
H: Back branches in code
While reading this file on software hazards this slide says:
"No Back Branch in the Code"
I wonder what does it mean? Normally when we write code in C-language then we don't actually do branching explicitly as in the case of assembly language programming. Does it mean that the above design ru... |
H: Identify dead component in notebook battery
Battery name is GARDA31, based on bq29330 and bq8030.
Most probably I killed it myself when soldering by shorting terminals with solder wire :( Controller is alive (communicates through SMbus), but shows "critical" and 0% charge in the OS.
The marking seems to be
R005
FZ... |
H: Simplifying electrical circuits
I have looked everywhere, but I can't seem to find a way to simplify this circuit. I wish i could tell you some of my ideas, but I'm really lost here, can someone help me? If you could explain how to go about it, it would be awesome.
AI: The schematic is a bit confusing, because the ... |
H: Capacitor Replacement - Markings: 622JA - GD 1000
My tube light choke was not working, I tested its circuit using multi-meter and found that a capacitor (labeled 622JA on first line and GD 1000 on second line) was short-circuited so I pulled it out and tested, same result.
There is no documentation or information a... |
H: Does the 433 MHz transmitter/receiver, transmit the voltage?
The title, says it all...
I would like to know if the 433 MHz transmitter/receiver (couldn't find a datasheet, here is all I found on it) transmits the voltage, or if it just a logic output of '1' or '0'?
For example, if I send through the data pin on th... |
H: Are current and voltage orthogonal in a transmission line?
If there is a phase difference on a lossless transmission line between current and voltage, is it always 90deg? Assume the Load matches the transmission line characteristic impedance.
If not what are the conditions for the phase not being 90deg (load or no ... |
H: What's this regulatory symbol?
I am trying to identify this symbol as a part of personal research. I could not find any leads with Google Image search.
AI: That's the symbol used by the Ukrainian State Committee for Technical Regulation and Consumer Policy.
I'd give you a URL but the links from their Wikipedia Page... |
H: Please help identify capacitor - turntable motor drive PCB
My Rega Planar 3 turntable is belt driven. It has been a year in storage, and now the platter spins backwards. A Google search suggests that one of the motor capacitors is to blame.
I reckon I'll replace both, as the turntable is over 20 years old. But sin... |
H: How to terminate unused transformer pins?
What is the correct way to terminate/wire these unused transformer pins? Do they get tied to GND?
AI: You don't do anything with them, they are fine if they are floating and left open. If you're worried about a charge developing on the coil (which probably won't happen), yo... |
H: SVC-350 Power Supply Modification
I am trying to modify a Roland SVC-350 that is currently configured for 240V power to run on 120V. I ran into some questions as I was speccing out the transformer that I needed. The full schematic can be found here, but the relevant section is here:
note: The OP-143 fuseboard sh... |
H: Role of syscalls.c
What is the role of syscalls.c file in GNU ARM(STM32 for instance) based projects? I found 2 ways of successfully building the project
Delete syscalls.c and include -specs=nosys.specs in the linker flags
Simply include syscalls.c
What is the fundamental difference between these two methods? W... |
H: 4mA to 20mA transmitter design question
Checking Vishay AN54 using IL300 for current loops, the Figure 6 (Isolated 1 V to 5 V, 4 mA to 20 mA Transmitter) circuit is explained but I really don´t get exactly how it works.
Other interesting document on this IL300 device is here, where multiple circuit topologies are ... |
H: How can I sum two PWM signals of different frequency with a Op Amp?
I need a suggestion how to sum two PWM signals, PWM 1 + PWM 2 to an output that have them both included.
Questions:
Is this possible? Other suggestions?
What Op Amp do I need to use if I want the output handle heavy load of 12 volt? I'm going to ... |
H: Why does a Peltier cooler heat up when cooled by ice?
On this post, the question presents a problem of a Peltier cooler heating up after operating for a while. The explanation was that the Peltier cooler is only able to maintain a fixed temperature difference between the cold side and the hot side. Because of this,... |
H: Simplifying a Boolean expression that has 3 variables in it
Problem:
Simplify the following expression using Boolean Algebra:
$$ z = (B + \overline C)(\overline B + C) + \overline{ \overline A + B + \overline C} $$
Answer:
\begin{align*}
z &= (B + \overline C)(\overline B + C) + A \overline{B} C \\
z &= \overline... |
H: Why do older (green) PCBs have primarily a darker color, whereas new ones are lighter
Note the difference in color between this old commodore board and this newer board. It might seem like lighting, but after looking at my own collection of scrap boards, the older ones tend to have a much darker color than the new.... |
H: Using open termination to intentionally reflect RF signal
Part of the calibration for an RF system we designed involves measuring the frequency response so that we can equalize the return. Part of this calibration requires measuring the reference response of our test setup so we can remove it during our calculation... |
H: String DAC - Question
I was reading about String DACs here https://www.allaboutcircuits.com/technical-articles/voltage-mode-r2r-dacs-operation-and-characteristics/
and I saw
Is the highlighed wrong? I mean, if just SW4 was on, shouldn't the output analog voltage be 1/2 Vref, since there are 4 resistors above SW4 ... |
H: STM32 Nucleo UART2 tx/rx pins wired to UART3 tx/rx pins
I am exploring UARTs on the STM32F103RB on a nucleo board. The board is connected via USB to my laptop, and I can send/receive messages using the HAL_UART_Transmit_IT and HAL_UART_Receive_IT functions.
What I am actually failing to do, is send a message from U... |
H: Why does my IR receiver spit out random codes when my motor is on?
I'm learning electronics and trying to understand why my IR receiver spits out random codes when my motor is on.
I have a basic setup with this:
Arduino
Power supply set to 5V
IR sensor receiver module
PN2222A transistor that turns the motor on/of... |
H: Can I use a ST-LINK V2 as a universal JTAG or TTL serial interface?
I have a ST Link V2 as pictured below. I would like to use it as a general purpose JTAG and or Serial TTL USB interface for communicating with a wide variety of devices. The documentation claims it supports SWM, which appears to be JTAG, but it's u... |
H: Capacitor Discharge Pin 7 555 Timer
I am very new to electric engineering, so bear with me ;) Before building the circuit IRL, I wanted to try to build a simple 555 timer with a simulator following Ben eater's tutorial on it. Here are the schematics of the circuit...
If you want to see the tinkercad project... Now... |
H: Why does this electret microphone with op-amp circuit cause the negative half wave of the signal to distort?
This circuit works quite well with low signal levels, but when the RMS AC signal is approximately 0.8 to 1.0 V (measured on pin #1 of the op-amp,) the negative half wave of the sinusoidal signal is distorte... |
H: In practice, what is the difference between the "nominal plant model" and the "plant model"?
I am reading a book on nonlinear control and disturbance rejection, and in many examples, they distinguish between the "plant model" \$G_p(s)\$ and the "nominal plant model" \$G_p(s)\$. They also add that the discrepancy be... |
H: How to classify power electronics components in 2 main groups?
I'm working on preparing a course about power electronics, and with my basic search conclusions. I thought that if it's possible or acceptable to classify the power electronics components in 2 main groups.
Group1: Controlled/Uncontrolled rectifiers
Incl... |
H: Is it possible to create power factor compensation for a single power supply?
A 24V 150W power supply's power ratings is marked on its surface as follows:
In this case as you can read the cos phi is 0.45.
I know that the utility which provides power to the systems wants to supply low current so by compensation the... |
H: can use these printer motors to made CNC machine?
can i use this motor to make a cnc plottor ?
is there any way to make a stepper motor using this motor?
AI: No. That is a simple motor. It cannot be changed into a stepper. To use a simple motor then you will need feedback, an encoder. You will be better off gettin... |
H: CPU cache write policy - evict already dirty? + storage of memory address
I'm reading about cache in wiki https://en.m.wikipedia.org/wiki/CPU_cache and the following phrase seems not clear.
Also, a write to a main memory location that is not yet mapped in a write-back cache may evict an already dirty location, th... |
H: Why are there 2 connectors on li-ion batteries
I'm looking at just about any assembled li-ion battery pack for sale and they all have 2 connectors coming out (4 wires total) and I'm wondering why is that?
AI: Li-ion Ebike batteries often have a built-in BMS (Battery Management System) or PCM (Protection Circuit Mod... |
H: Help identifying pins in EVQV9C00116E rotary encoder
I'm trying to make a button box for a sim racing rig and need a few rotary encoders for menu browsing. I plan to connect it to an arduino but I can't seem to figure out how to wire things up. I have found the datasheet for the encoder, but can't figure out what ... |
H: How many ALUs (and threads) are in a Pentium CPU?
I'm reading a book bottom up where it said:
The Arithmetic Logic Unit (ALU) is the heart of the CPU operation. It
takes values in registers and performs any of the multitude of
operations the CPU is capable of. All modern processors have a number
of ALUs so... |
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