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H: Series or parallel fan connection
So I wish to wire a project that uses three 12 V fans but I don't know if I should get a power supply with 12 V or 36 V.
AI: Use 12V and wire the fans in parallel.
If you use a 36V power supply and wire the fans in series, the voltage might not be shared equally. This could even c... |
H: Voltage regulators in series
I'm trying to figure out if my power distribution setup is hurting my circuitry.
Below is a picture of the setup for one device:
The power supply is a wall adapter rated for 6VDC/900mA output.
The middle item is a special power hub I created from two pins of each USB plug and it is pow... |
H: My RT8272 buck dc converter fried in my test charging circuit for arduino
I'm building a circuit to power an arduino and later a stepper motor from a 3A 24V DC source. The DC power source is a switching power supply, much like those used in notebooks.
I'll need after powering off the circuit, 3-4 seconds of charge... |
H: Fatal Error Audio equalization simulation LTSpice
I'm doing a 3s audio.wav simulation on LTSpice with the following circuit (3 band pass filters and amplifiers):
In this example it's boosting the bass and attenuating the highs.
It loads the first second really fast and then it start to take a longer time:
When do... |
H: PCB Panelization Impact
What is the impact on a PCB design if it is panelized? I received a message from a PCB manufacturer:
In your order, the quantity of boards is large and the boards are quite small. Can we panelize the boards for easier handling? If no, will cost an extra $32USD additional
While I wouldn't m... |
H: Thermal resistance Junction - Maximum Power dissipation
I want to understand the real meaning of the parameter 'Thermal Resistance Junction to Air (°C/W) to calculate the power dissipation. So for example if the value of this parameter is 250°C/W, should I take this value as a constant if my ambient temperature is ... |
H: M.2 PCIe x2 and SATA connections and key/notch with SATA/PCIe x4 SSDs
For my current project I am adding an M.2 slot for additional storage. Even though SATA data throughput is more than sufficient I would like to support both SATA and PCIe based SSDs, as I dont know what will be more/less available and affordable ... |
H: What is the Voltage on a tablet's battery when it is turned off
Basically I tried to find out what's wrong with my broken tablet, so I used a multimeter to measure the voltage at the battery pins on the tablet's board and it was 0.1 roughly, and the transistors had some voltage on them, but the device was not booti... |
H: Can analogue Hall sensors be used in BLDC for static angle measurement?
Everything I have read on using Hall sensors with BLDC motors appears to use latching hall sensors which provide repeatable latching angles as the magnetic fields change at specific angles. I am wondering if an analogue hall sensor can be used ... |
H: Why are core losses mechanical and not electrical in an AC power flow diagram?
The power flow diagram of a generator (a) and a motor (b) are shown. But why are core losses mechanical losses?
AI: The synchronous motor/generator has two power ports, a mechanical power port at the shaft and electrical power port at t... |
H: I2C in STM32F103 longer data
I am trying to use PCA9539 as an IOexpander for my project. I have a STM32F103 connected to PCA9539 via I2C.
The problem I have is to write into PCA9539. Based on the datasheet I should to send (1) address (2) command byte (3 and 4) data bytes via I2C. When I check the I2C bus lines wit... |
H: Driver circuit calculations
I am attempting to built this circuit here:
It is used by an LED manufacturer to provide pulses to a high-power LED. In my case, I'm using an ARDUINO to provide the TTL signal. I haven't sourced the other parts yet as I'm trying to understand the system first.
I'm a bit confused as to ho... |
H: Arduino RGB spectrum problem
Over the last few days I've been working on an anode RGB LED in Arduino, I've tried getting it to do an RGB spectrum but all I would get is just the colors from red to green, then it would get stuck on white and cyan, I believe that the red LED in the RGB Anode turns on and off, as the ... |
H: JK flip flop PRESET and CLEAR function
I understand that Preset and Clear inputs are asynchronous inputs which means whenever Clock signal is low one of them can immediately set the output to 1 (Preset) or to 0 (Clear) (assuming they are active high inputs). But I wonder what happens when one of those inputs has be... |
H: Rotary encoder sensor
Is there a way to get reading from rotary encoder without microcotroller?
just simple circuit that count and increment, like op amp or 555 timer or logic gate . anything that u can help me .
AI: Is there a way to get readings from rotary encoder without micro controller?
Yes
BUT, the encoder ... |
H: How do I program an ItsyBitsy 32u4?
How do I load code onto a ItsyBitsy 32u4 without using the graphcial Arduino IDE?
I've looked for "ItsyBitsy 32u4 programmer" and ItsyBitsy 32u4 bootloader".
AI: You could use the AVRDUDE software from command line. See e.g. https://learn.adafruit.com/atmega32u4-breakout/using-w... |
H: Is it possible to help accelerate a starting motor externally?
I have a rather small motor and a matching energy source.
When the motor starts, it needs a (short) amount of time to 'rev up', to accelerate at its max speed.
Is there any cause for this other than mechanical inertia and friction? Would, say, a pullcor... |
H: How to upgrade StdPeriph drivers for STM32F103 project
I have an old project which is built on using "StdPeriph drivers" for STM32F103 MCU and Keil environment. It uses various drivers for gpio, adc, can, dac, dma, i2c, spi, tim, uart etc.
As these drivers are obsolete now so I want to move to new available ones. B... |
H: Does USB power delivery support arbitrary voltages?
I'm looking for a USB power delivery power adapter to charge my Canon EOS RP camera via its USB-C port. Canon sells its own adapter for insane prices, and the Canon adapter is apparently nothing but a USB power delivery adapter, so according to my logic, a cheaper... |
H: Three terminal LED pilot. What's the matter?
Long story short, I've purchased a 24VDC LED pilot and I've got a 12VDC pilot with three terminals instead. I was wondering what are each one of those three terminals for, the terminals have standard names (X0, X1, X2) but in the case there are additional names written (... |
H: Normally closed mosfet circuit
I'm designing a battery charging circuit for a portable device. Conceptually it looks lik so:
simulate this circuit – Schematic created using CircuitLab
As a safety function, the circuit can be interrupted by the transistor, thus interrupting the battery charging process. What leads ... |
H: What does the multimeter dial do internally?
Everyone who has ever handled a multimeter is familiar with these dials. The position of the dial indicates the maximum range of the quantity that can be measured.
But why are we required to adjust the maximum range ourselves? What happens internally in the multimeter w... |
H: Why less protection on a GPIO RS485 board compared to an UART RS485 board?
When I search for RS485 board (to be used for my Arduino to control DMX512), I find mostly two types:
GPIO / TTL based (which I want to use), like TTL RS485, which mainly has a MAX485 and some resistors/capacitors. This one works with DMX51... |
H: Which is a better conductor, a very thick rubber wire or a very thin copper wire?
I read somewhere that very thick wires are generally better conductors than very thin ones. Is this true? If yes, then would a very thick rubber wire be a better conductor than a very thin copper wire?
Edit: By rubber wire, I mean a w... |
H: Need a non-volatile memory IC with near unlimited read/write operations capability
I need a memory solution which is going to be used to keep track of an accumulated count on a micro-controller based project.
By accumulated count, I mean to say that the micro-controller uses this memory location to keep count of th... |
H: Magnetic induction with varying rpm: Dealing with excess energy
I would like to get some advice regarding the following scenario:
I want to build a cheap, small generator for an energy harvesting application. There are magnets on a rotating shaft and off-the-shelf inductor(s) are positioned (fixed) near this shaft.... |
H: Mosfet Gate Resistor
I am building a high power ZVS induction heater. I originally used this famous design. It worked like a charm when I used a 48v 31A power supply. But I want an upgrade. I recently got a few of these FCH072N60F 600v 52A power mosfets. They have a low Rds on, fast switching and low gate charge. A... |
H: Are Verilog if blocks executed sequentially or concurrently?
I'm learning Verilog with some background in VHDL and C. I would like to know if Verilog if blocks are executed concurrently or not, and if this is IDE- or vendor-dependent.
For example, are the following always equivalent or never equivalent, or sometime... |
H: Is space division multiplexing really multiplexing?
I don't know much about electronics, but happened upon the Wikipedia article for Multiplexing, which defined it as:
a method by which multiple analog or digital signals are combined into one signal over a shared medium
Shortly after are listed different types of... |
H: Switching 10 contacts with one switch
I am looking for a way to switch 10 contacts but without having to switch these tiny contacts one after another. So basically one movement, 10 contacts open/close.
I saw this little switch:
But there I have to swtich them all. Unfortunately I didn't find anything useful in the... |
H: Razer Laptop Power MOSFET replacement
I have a failed power mosfet on my board which is PSMN3R0-30
https://assets.nexperia.com/documents/data-sheet/PSMN3R0-30YL.pdf
It has low Rds (on) = 3 mΩ
It is common for these to fail in these laptops (poor design) and would like to know if I can replace it with a more suitabl... |
H: Does "1KV" on this disc capacitor mean 1 kiloVolt?
One of my power supplies died. Investigation turned out that this capacitor is broken. "102" means 1nF, but does "1 KV" mean 1 kiloVolt or is that some sort of tolerance code?
I've tried several "capacitor code calculators" but none of them mentions "KV" (only K, w... |
H: 1500-6000V linear regulator (noise eater)
Is there any known approaches to regulate HV in the range of 1500-6000V in order to eat noise? Low-side regulation is a possibility.
The idea is to get ~100V higher voltage than needed, and then regulate it down with a linear regulator in order to achieve lower ripple nois... |
H: Switching between battery and external power sources with reverse polarity protection
In my design, I will use AA batteries to power the electronics board.
As a requirement, also it should accept the power from external power supply (12V) - The board should automatically switch from battery to external source.
- T... |
H: My Buck-Boost Converter Circuit Isn't Working
I am currently working on a heated glove project using a Buck-Boost converter to adjust the temperature of the glove. I'm using the LTC3112EDHD#TRPBF QFN Buck-Boost IC to control the Buck-Boost functionality. I just finished soldering my test PCB, and my Buck-Boost Conv... |
H: High Side Switching Inductive Load with MOSFET
I am attempting to make a PCB that high-side switches an inductive load (water pump) that draws 4.6A peak. The switching scheme will not include any PWM, just basic on/off functionality.
My concern is clamping the voltage spikes from the load during turn-off. I want t... |
H: VHDL: is there a way to create an entity into which constants can be passed?
Lets say we want to create a generic t flip flop counter, the structure of this kind of counter is perfectly repetitive, and you can synthesize one with arbitrary length just using a for generate
however the bound for that for and the leng... |
H: Use of Power Pins in ICs
This question might seem very basic, but it will help me a lot if someone can answer it from the basics!
I have just finished my first year at college and there was a course on digital design, where we studied the fundamentals of digital systems and also implemented various circuits using I... |
H: Why don't motors coupled to gearboxes spike up significantly?
A 5,5KW motor is rated 11,40A for the delta connection at 400V. This motor is coupled to a gearbox that reduces it's speed from 1440rpm to around 121rpm. On the gearbox shaft is a sprocket and chain which reduces the speed even further.
According to wha... |
H: Op Amp integrator (square to triangle) not always start working correctly
I created an Op Amp integrator with LM358 to convert square wave to triangle wave as shown below.
simulate this circuit – Schematic created using CircuitLab
Though the circuit sometimes works as I expected, but sometimes when I restart my si... |
H: Can I use 1 transistor to switch on and off 3 loads?
I am running an ESP32 microcontroller with a Co2 sensor, a real time clock (RTC), and an SD card reader. I will be putting the microcontroller into deep sleep and waking it every hour. I want to switch off the power to the aforementioned components before the m... |
H: Complementary transistor pair with a bipolar transistor and a MOSFET
I own a set of Soviet IN-14 Nixie tubes and I would like to use them to make a vintage clock. I found this example schematic of a "Nixie clock":
I don't understand what is the purpose of using a MOSFET in the second stage of this quasi-"Darlingto... |
H: How Qi charger reads data from receiver
I saw a guy making Qi receiver module with ATTiny13A: Qi wireless power receiver from scratch.
In his circuit, secondary shorted through capacitors to ground to send data.
My question is how transmitter side (base) reads this data?
AI: When the output is loaded, the power dra... |
H: What misconception about telephone circuits are they trying to address?
I'm reading a book called "Telephony" published in 1905 (Miller,Mcmeen).
The book starts with this quote:
To properly understand the manner in which sound is transmitted from one end of an electric circuit to the other, it will be necessary t... |
H: Different colors for Power Transmission Towers
I have observed that some areas have some power transmission towers painted in Red and white colors. But, more often, transmission towers are unpainted. An illustration of what I mean by this,
Left: red and white tower, right 'regular' tower
If I am right, radio/cell-... |
H: Why polling works rather than interrupts
I have several devices like for example connecting with ESP8266.
I have tried to use the SPI with it with STM32F4.
First I have tried to work with SPI interrupts, the result of the communication is not stable, sometimes the communication works between both, sometimes it doe... |
H: Minimum Current(not for switching) On a Relay?
I'm trying to understand how the pictured device works. It's a Sonoff WiFi controlled electrical relay. I was told that it is designed to control mains voltage only, and cannot be used to control a 5v dc current. This doesn't make any sense to me, because I'm under th... |
H: Using a low-voltage switch in a high voltage circuit
I have an application that requires switching a circuit between the following two configurations. Circuit Lab is infuriating as it does not allow you to draw diagonal wires, so I used arrows instead. They are not connected in the middle.
simulate this circuit – ... |
H: Do high and low side labels on bidirectional logic level converters matter?
Logic level converters like this one from Sparkfun have high side and low side labels on them. Now i have an application where I think I need to shift logic levels but the high side and the low side are likely to swap at some point due to c... |
H: How can I make it so that customers who buy my arm based product can easily update the firmware?
I'm building an arm-based (stm32F7) hardware device which will have a USB port. I would like to be able to update the firmware and distribute it such that customers with my device can easily install new firmware without... |
H: Microcontroller core voltage
Can someone provide me some explanation or clarity regarding the three internal voltage regulators that this Microcontroller has mentioned in chapter 40, page 1227.
From what I read, I think that we are not providing the core voltage (1.2V) to the micro directly. We are providing 3.3 to... |
H: Liquid / water level detection safely using AC voltage - Industrial circuit explanation
I am planning on working on a project to build a controller which will be used to detect the levels of water treatment chemical tanks and display them on a bar graph. then switch off the dosing pumps once the chemical tank level... |
H: Abuse TS339 comparator channel as a voltage multiplier
I have multiple free channels of a TS339 amplifier remaining and would like to use one of them to multiply voltages like this:
simulate this circuit – Schematic created using CircuitLab
Now it's a common rule that you should never use OpAmps as comparators or ... |
H: LED glows slightly during soldering
I recently soldered a number of white LEDs to a PCB using a Weller "standard" soldering station. I noticed some LEDs were glowing slightly during soldering. The PCB was placed on an ESD mat, but I doubt that this had an influence. Is that a thermal or electrical effect?
I suspect... |
H: How to work out this implementation of chua's diode?
The author of a book claims that this is the implementation of Chua's diode by [Kennedy, 1992], although I cannot find this article. My question here is, how does this circuit work? For me, the diagram is a terrible mess.
Note: The circuit shown misses a connect... |
H: Is it possible to program a RFID tag like a microcontroller?
I am working on an RFID project. I want to be able to send specific messages between the reader and the tag or maybe perform my own protocols on it. Is there a type of tag that I can provide some sort of firmware for? (be able to program it like a microco... |
H: USB Type-C wires
I have a USB type-C rapid charger 5V/3A, want to use that for one of my projects but there's 8 wires and i can't tell which is which to get 5V out of it!
sorry for the blurry image, couldn't get the camera to zoom properly.
there's 2 orange, 2 red, white, yellow, green and shield wire.
How can i c... |
H: Is a 4p4c rj22 plug physically compatable with a 6p6c jack?
cant seem to find any decent panel mount rj22 jacks but rj12 looks pretty close, and I cant help but wonder if it will fit.
AI: An RJ-22 plug will fit into a RJ-11 or RJ-12 socket but the RJ-22 plug is much more narrow than the RJ-11 /RJ-12 plugs. This wil... |
H: How does a capacitor affect the flow of the current?
I understand that the capacitor is like a secondary DC source when it's almost fully charged. What I don't understand is the way it behaves in a circuit.
It discharges itself when it's full or when it is the only DC source in a closed circuit?
Consider this slow-... |
H: Is there a good way to test your schematic before buying the parts and building it?
I'm trying to design a BMS that can handle 12 cells, be powered either with a isolated dc-dc converter or the batteries themselves and uses active balancing, but I'm not sure if my design will work:
AI: No there is not, computers wi... |
H: Forward Error Correction over Unidirectional Serial Link
I’m designing a master-slave, one way RS-485 over plastic fiber optic physical link layer network using low power PIC MCU. While I expect the link layer to be very reliable, nothing is ever perfect.
Since the network is unidirectional to keep costs down, I’m ... |
H: What is the purpose of these diodes?
What is the purpose of these didoes? I couldn't find it because I don't know it's name.
Thank you.
simulate this circuit – Schematic created using CircuitLab
AI: On the left is a full-bridge fully-controlled thyristor rectifier. With that circuit it's possible to turn DC into A... |
H: Colpitts oscillator : having trouble while respecting Barkhausen criterion, is this criterion insufficient there?
I'm trying to simulate a Colpitts oscillator.
I've determined transfer function of the low-pass filter of this circuit:
I reached this expression: \$H(j\omega)=\frac{1}{1-LC_2\omega^2+jR_3\omega(C_2+C_... |
H: How to make an electrical connection to thin gold plating?
Hello fellow engineers.
I am trying to make an electrical connection with some gold plating. The gold plating is shaped like a rectangle, with dimensions of 3mm x 1.5mm x 0.1μm thick. Here is what the part looks like, it's quite small.
My procedure is:
T... |
H: Help with thevenins voltage
Have to find the power developing on the 7k resistor (I*U).
Calculated (hopefully correct) Rthevenin to be 12k//4k which would be 3k.
Circuit simulator shows that the current through the resistor should be 3mA but i can't figure out how to get to that number with the voltages provided, s... |
H: servo control using a microcontroller and separate power supplies
I'm trying to get a very basic servo control circuit to work using an Arduino and can't figure out where I'm going wrong. I've got separate 5V power supplies for the microcontroller and the servo, grounds are connected (through the microcontroller) a... |
H: Wiring USB 2.0 to USB C Receptacle
I have a keyboard that uses a USB 2.0 cable to connect to the computer. I would like to remove the current USB 2.0 cable and replace it with a USB C receptacle. The goal is to be able to connect the keyboard to the desktop with a male to male cable (USB C to USB A or C).
My proble... |
H: LTspice: Including Time Derivative of a Node Voltage in Initial Condition
I am trying to simulate an RLC circuit with the initial condition that V1(0)=2 and V1'(0)=0. I used D(V(V1))=0 in my spice directive, but I don't think the condition on time derivative has actually been implemented.(D(V(V1)) is negative inste... |
H: How to find Gate charge
I want to drive a 650V 21A SiC mosfet at 100kHZ. Would this mosfet driver be able to drive the mosfet?
How can I find Gate charge of the mentioned mosfet gate driver?
The mosfet I am planning to use is SCT3120ALHR.
Please suggest if this driver will be able to drive the mosfet.
If not, the... |
H: LTSpice: simulate transient voltage and current in RL-circuit
My goal is to calculate transient current and voltage in a following circuit:
Also, immediately after the switch is closed, initial current is 0 and then it exponentially increases until the value reaches the value defined by the steady state. Mesh anal... |
H: Comparing MAX3232 vs MAX232 for line length
Which parameter in the datasheets of the line drivers MAX3232 and MAX232 can tell about the maximum length of the line for their correct operation if all else is same for the two circuits, that is baud rate = 115200, Vdd = 5 V, same UTP cable used.
AI: 100 ohm twisted pai... |
H: Custom bootloader passing control to application code in STM32
I am trying to understand that if for STM32F405 MCU a custom bootloader is used on the MCU then each of the two projects for the custom bootloader and the application code will have their own 'startup.s" files.
What I understand is that both of the two ... |
H: Why does this potentiometer in an op-amp feedback path cause noise when adjusted?
I have placed a dual-gang 100k potentiometer in the feedback path of two op-amps that work as a Sallen-Key filters. This controls gain but also the Q factor of the filter (somewhat demonstrated on wikipedia. However, when I move the k... |
H: Where does STM32CubeMX generate AF GPIO initialization?
i was wondering where does CubeMX (when you export it to an IDE such as Atollic) generate GPIO initialization for alternate functions such as Timer capture pins, UART pin ect. (we are talking about HAL drivers) I've noticed it's not initialized in GPIO_Init no... |
H: Need Help To Identify Attached SMD Component
I am trying to fix a RS485 circuit.
There is 3-pin protection components on both A and B pins.
The component is connected serially to the line and mid pin is grounded.
There is no label on the component.
The resistance is nearly 0 ohm and the component is short circuit b... |
H: What is Mikrobus purpose?
I'm new to embedded systems. I have MPLAB Xpress Evaluation Board.
I see that the board has MikroBUS connectors. Going through the internet, I couldn't understand what is the purpose of the MikroBUS? Which functionality does it allow? What is the way to connect to it?
AI: The specification... |
H: Use a TVS device to protect meter from live capacitors, workable or not?
I've been working on a LCR/Impedence meter and want to protect my inputs from possible damage if I forget to discharge a large cap.
I know I've seen various types of diodes and relays used for that purpose. But from what I've read and experie... |
H: Why is the air gap between the stator and rotor on a motor kept as small as it is?
Between the stator windings and rotor is a small air gap. What would happen if this gap were larger than it is? Surely the magnetic field set up by energizing the stator windings would still cut the rotor and induce an emf across it.... |
H: How to substitute this pickle switch with a software controlled switch?
I'm working as a research assistant. We have three high frame rate cameras that currently save the recorded video when the pickle switch (purple cord) is manually pressed. I want to replace this purple pickle switch cable with a microcontroller... |
H: Half Bridge Low Side Mosfet vs. Flyback Diode
I intend to use this high side switch in a PWM application with a brushed 12V motor drawing 8A steady state max: https://www.nxp.com/docs/en/data-sheet/MC33981.pdf
The switch allows for a half bridge configuration, where an external low side MOSFET is placed across the ... |
H: Switch LED with Solid state relay (PhotoMOS)
The SSR is a PhotoMOS AQY211EHAX rated to drive 1 amp. I seem to be shorting the output side of the SSR.
Is a pull down resistor normally required on the output side or am I missing something fundamental?
AI: You still need a current limiting resistor on the LED. There ... |
H: PIC12F675 ADC not working properly
I wrote a code that takes an analog input from a potentiometer and controls the frequency of a clock pulse. So, the idea is to increase the frequency when I increase the pot and decrease the frequency when I decrease the pot. It should change at a constant rate.
The problem:
When ... |
H: Trying to find value of two capacitors using resonant frequencies in three conditions, but wrong formula is derived
I was trying to find capacitance of two capacitors in the following way.
Connect each capacitor individually to a same inductor and find resonant frequency in each case.
Connect the same capacitors i... |
H: How does one position control a voice coil actuator?
I am looking at trying to position control a voice coil actuator (something like these). On the end of the voice coil actuator will be a small load (let's just imagine a 10 oz cube), screwed onto the end of the shaft.
Here is where I come from. When position co... |
H: Re-soldering SMD with SMD rework station
I recently purchased a clone 858D SMD rework station and would like to get familiar with de-soldering and re-soldering SMD chips.
I was able to de-solder fine, but when trying to re-solder I can't seem to get all the legs to solder onto the PCB. My question is, what could be... |
H: LDO vs Switching Voltage Regulator for Drone Application
I have been designing a drone flight controller and currently have been using LDOs to regulate the voltage to 5V.
As I have started to use higher voltage batteries the LDOs have started to overheat. I know that switching regulators are so much more efficient ... |
H: Designing an effective power supply for embedded products
I'm currently designing several embedded microcontroller products to be powered from a wall outlet. I plan to use wall-wart power supplies to give an input of approximately 5-9V DC but I want the input of my device to work at up to 30V just for the sake of c... |
H: I2S to PDM Conversion
We are looking to use the TLV320AIC3111 audio codec to process some sound data that we are receiving from MP34DT05-A microphone. We then look to transmit the data wirelessly over BLE using the BlueNRG-1 BLE Module. We've already worked on the BlueNRG-1 and have managed to transmit PDM data inp... |
H: Power Amplifier Modification
I am trying to build this amplifier. Looking at the diagram, am pretty sure how it works, but is there a way I can modify this variable resistor with some fixed ones?
AI: Your variable resister is for setting up the idle current in the main powermosfet bank .More resistance means more g... |
H: Triac power dissipation
I'm driving a high power load with the BTA440Z (datasheet):
line voltage is Vac = 230 AC, load power is P = 1.33 kW, thus load current is ~ I = 5.8 A.
If i swap the load with another that draws P = 2.33 kW, then I becomes ~ 10 A; in this condition the triac overheats and it doesn't un-latch ... |
H: Correct Initialization Routine for LCD Panel (HX8357D)
I have acquired a color 320x480 TFT LCD display based on a HX8357D driver. It is an Adafruit 3.5" Touchpanel display. I would like to use it for one of my projects based on Rust. Currently, there are no drivers out there for Rust and therefore I plan to pull... |
H: Why are all my yellow 2V/20mA LEDs burning out with 330k Ohm resistor?
I have a very basic circuit on a breadboard using an Arduino's 5V+Gnd to power a few LEDs. All the LEDs are from Sparkfun and rated at 2V/20mA, coming in Red, Green, and Yellow. I'm using 330 Ohm resistors but I also have much higher resistors l... |
H: Why different SOCs have different CPU power voltages for given frequency?
Recently, I studied dvfs tables for 3 SOCs: exynos8890(LITTLE cluster), exynos7880, snapdragon 625.
Here is the result:
octave source code
The point is, that different SOCs with pretty same manufacturing process (14nm), same CPU architecture... |
H: TSOP34838 noise in dark areas
I'm using a TSOP34838 IR reciever on an ATMEGA MCU, However, I see a problem in dark areas... If I put my finger in front of the receiever, it starts spewing out garbage, even worse when the room is completely dark (intended use case is a custombuilt rgb controller, so.. darkness is ki... |
H: Assigning a 16 bit number to two bytes of a buffer
Currently I have this out buffer that I am assigning values to like this:
char out_buffer[OUT_DATA_SIZE];
…
out_buffer[7] = 0xD0;
out_buffer[6] = imu_union_ACC_Y.byte_data[1]
out_buffer[5] = imu_union_ACC_Y.byte_data[0];
out_buffer[4] = imu_union_ACC_X.byte_data[1]... |
H: What is the benefit of a mosfet gate drive which is constantly biased instead of driving to ground?
I recently came across a circuit with a drive signal which never went to ground, and instead always kept the MOSFET biased. What it the reason/benefit of doing this?
I've drawn an example like the circuit I saw, wher... |
H: How can I trickle charge NiMH batteries as part of an IOT controller?
I have built an IOT motor controller board that's powered by 4 AA NiMH batteries in series. I want to use a solar panel to trickle charge the batteries, but the voltage slowly decreases even when the ESP12F WiFi module is sleeping and there's ful... |
H: Why we see a spark when we connect a plug into an already switched "ON" socket?
Why we see a spark when we connect a plug into an already switched "ON" socket? But I've also noticed that this isn't the case always, ie. sometimes when connecting a plug into a socket which is already "ON" it doesn't spark, while some... |
H: What is this triple-transistor arrangement called?
For an old Fuji 2DI200D-100 power transistor module, it uses three transistors internally for each half-bridge:
The circuit in question doesn't connect to the middle bases at all, just B1 and B2, so this (dual) triplet is being used solely as two big transistors.... |
H: Digital Logic Design - Sequential Circuits
The circuit diagram below is in a stable state because of the two inverters. Why and how did it reach a stable state?
AI: If you accept that a logic level can be only 0 and 1 it is clear that the circuit must be in one of the two states, because there are no other (stable)... |
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