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H: EEPROM usage in ZS-042
I have bought a realtime clock module (this one). According to the sparse data I found there is a EEPROM on it. It's called 24C32 as can be seen on this schematic I found:
As I want to rebuild this schematic as a part of a custom PCB I wonder what this EEPROM is used for? What would be the i... |
H: 10000 pF - so many zeros
Why are 10 nF capacitors sometimes (usually) specified as 10000 pF?
Why are we trying so hard to avoid nF? Seems unnecessary and error prone.
Note: Question also relates, of course, to 1 nF vs 1000 pF - of which there are four 1 nF ceramics on Digi-Key, versus nearly 17,000 1000 pF (though... |
H: Digital data to digital signals with Non return to zero(NRZ)
NRZ codes share the property that voltage level is constant during a bit interval. High level voltage = bit 1 and Low level voltage = bit 0.
A problem arises when there is a long sequence of 0s or 1s and the voltage level is maintained at the same value f... |
H: Current transformer with no load?
The apartment complex I’m in is only a year old, so we’re still in the Defect period with the builders. I’m on the Committee of the Owners Corporation, so I get to see the utility areas. The builders put in private metering; those meters always show 243V (expected) but 0W. I just a... |
H: What is the use case for a tantalum capacitor?
I am doing some research on the different kinds of capacitors.
Here is my brief understanding of the use cases for each kind of capacitor:
Aluminum Electrolytic: Filtering low frequency, high current signals (such as rectified line voltage.)
low ESR at low frequencies... |
H: Soldering MEMS sensor
I have a problem with soldering the LIS2DH12 MEMS sensor accelerometer. I searched for soldering recommendations but I do not understand exactly how to solder.
I couldn't find the needed heat and time requirements.
The datasheet says:
leave "Pin 1 indicator" unconnected during soldering.
Th... |
H: Component in series with digital communication lines
What is the component highlighted in picture?
Main IC in the picture is PCM510xA.
AI: that looks like a resistor network. Basically four 33 Ohm resistors. |
H: Does phantom powered audio system's ADC also works on 48v
Phantom powered microphones with their preamplifier can generate signal from -48 to +48 volt (or 24 or 12), then it run through wire and maybe receiver and reaches ADC. I want to know if 48v signal is attenuated before DAC or directly (with ~48V peak) drivin... |
H: Opamp - find current coming to the noninverting input - the basics
In the picture there is an inverting opamp, so the equation for gain is:
$$ A_{CL} =\dfrac{-R2}{R1} $$
How can I find: $$U_⊕ , U_⊖, U_{wy}$$
How can I find the current (I)? (see picture)
What rules should I use?
AI: First off, this is a non-inverti... |
H: Questions on hooking up an old cathode ray tube (CRT)
I bought an 8LO29I Soviet era CRT (intended for use in oscilloscope/instrumentation):
Now I'd like to get it to work. After almost endless reading up (I'm not an electrical engineer) I think I now know what to do. The CRT also came with extensive original docum... |
H: Voltage divider formula
How to find value for both R1 and R2 for Vout=1.23 volts, where Pot=5K, Vin=4.5 - 12 volts?
simulate this circuit – Schematic created using CircuitLab
In reality, I want to adjust lm2596 buck converter output to 4.5 volts to 12 volts with any potentiometer, by adjusting R1 and R2 value.
For... |
H: BJT collector power limit in pulsed usage?
Assuming that my circuit respects the voltage, current, and thermal limits of a BJT, can the device be electrically damaged by exceeding an instantaneous collector power limit?
In other words, are BJT power limits only for thermal protection, or is there some other way tha... |
H: Does coil winding impact current direction? (Lenz Law)
When a magnet is moving toward a wire loop north-side first, the current goes counterclockwise according to the magnet's perspective, as shown in the image below from Wikipedia. Now, consider a solenoid where each loop is wound so that travelling counterclockwi... |
H: What do OD and PP stand for in SD card frequency fOD and fPP?
It seems all SD card specifications mentioned two frequencies (fOD and fPP) as used in identification and data transfer mode respectively. What do the subscripts (OD and PP) mean?
AI: They mean Open Drain and Push Pull.
Identification is done slowly in O... |
H: Is choosing a high HSE frequency beneficial for the PLL CPU clock?
guys.
The NUCLEO-H745ZI-Q board didn't populate the high-speed external (HSE, 4-48 MHz range) oscillators and I'm planning to solder one.
I want to use the PLL so that the STM32H745's CPU1 clock can reach the max value 480MHz.
HSE frequencies like 8... |
H: Confusion about the estimated phase angle in SRF-PLL
I am working on a simple PLL Simulink model as a proof of concept:
I have two problems that are causing confusion for me at the moment:
What should the estimated phase angle look like? Mine is like this. I feel that something is not correct because all the ref... |
H: Large series resistor to protect from shock
I built a high voltage generator and want to protect myself against shocks.
Would putting a large series resistor on the powering circuit be sufficient to protect me in those cases:
I build a large Marx generator (large DC impulsions), and I put a 10 Mohm resistor on my ... |
H: Square wave to triangle wave converter using Op-Amp not working
I have built an integrator to act as a 5V 30Hz square wave to triangle wave converter.
My output currently looks like this.
I am unsure why. The value of the triangle wave amplitude, according to one of this posts' answer, should be 0.833, which is w... |
H: How to prevent body from influencing electrometer reading
I am setting up a lab involving a parallel plate capacitor connected to a 6V source and an electrometer. After disconnecting the voltage source from the capacitor, I attempt to find the charge stored in the plates by dividing the voltage of the capacitor by ... |
H: Op-amp output voltage offset
Hi i wanted to ask what causes an offset for the following integrator setup:
I`m no sure if its the virtual ground or another fundamental reason im not aware about since the signal should always be biased at 0V. If someone could help that would great thanks!
AI: The actual issue is that... |
H: Exceeding guaranteed memory write cycles
I have an STM32 MCU with integrated flash that has a specified endurance of 10'000 write cycles. What exactly is the risk if I exceed this number during my products lifetime? My understanding is that the 10'000 cycles are "guaranteed" by the manufacturer but what is the erro... |
H: LDO PSRR Value Problem
I am searching a LDO for my design but I have a problem. Some of the LDOs don't have PSRR value. So, I can not compare these LDOs then others for noise feature. For example here are 2 LDO.
Why these LDOs don't have PSRR value? What does it mean?
MCP1801T-3302I/OT
AP7354-33W5-7
(doesn't have ... |
H: How to replace diodes with MOSFETs?
The circuit shown below allows clips the output to +1 and -1. How can I replace the diodes with MOSFETs that have a similar behavior?
AI: Here's one with using NMOS:
simulate this circuit – Schematic created using CircuitLab
The diodes shown are body diodes. If you short gate an... |
H: DAC70508 connected to Arduino does not give any output
I am trying to use a DAC70508 with an Arduino Mega, but I do not get any output from the DAC.
I connected the SPI communication pins and the power supply pins of the DAC to the Arduino (Vio and Vdd to 5V), and I did not connect the REF pin of the DAC because I ... |
H: A question about memory address in microcontroller vs PC
In context of embedded C, considering the following line:
*((volatile uint32_t *) 0x48000414) |= 1UL<<12;
Now 0x48000414 can be a memory pointer to a hardware register of a memory mapped microcontroller. So the above code tells: Go to the register at the add... |
H: Noob questions about my accelerometer (ADXL345) and Arduino components in general
I've just bought this accelerometer: https://www.amazon.co.uk/XTVTX-ADXL345-Digital-Acceleration-Gravity/dp/B09NRFDH5J/ref=cm_cr_arp_d_pl_foot_top?ie=UTF8
I've bought it to learn about accelerometers and practise them with my Arduino ... |
H: LC filter for inverter
I am designing a 1500W inverter. With 24VDC input source and 220VAC 60Hz output voltage.
I currently have the topology shown in circuit 1. This results in a square wave at 60Hz. But I need the output to be a pure sinusoid at 60Hz. The M1 and M2 mosfets are driven at 60Hz by PWM and NOT_PWM.
T... |
H: How to use case for continuous assignment?
I get a bunch of these errors on the following code:
(VERI-1100) procedural assignment to a non-register 'nextstate' is not
permitted
The problem is mostly with the case statement.
I am genuinely confused. My design clearly cannot be implemented using clocked registers f... |
H: Why does this BJT leak so much collector current at cutoff with high V_CE?
I have some 2N4401 NPN transistors that I'm trying to use with a 12V supply. I saw some strange behavior at cutoff and reproduced it in this simplified circuit. (The base is not connected, in case the schematic is unclear.)
If I'm reading t... |
H: Inverter DC link voltage rises when motor decelerates
For a voltage-source-inverter (VSI) powered PMSM, as shown in the picture below, the DC bus voltage across the DC bus capacitor Udc normally drops frequently, which will cause no harm to the cap itself. However, when the low speed command is given, the motor wil... |
H: How to characterize an input signal?
I'm planning on doing some signal processing on my electric guitar with an MCU and I was wondering how I can characterize my input signal so I know if and what kind of pre-amp/ADC I'd need or if the MCU's ADC would be sufficient for my needs.
Typically when connecting a sensor o... |
H: MOSFET device selection for LED dimming
I am thinking of developing a controller that can adjust the brightness of 12 V, 50 A, and 600 W LED.
MOSFET 1 Spec
Model: NTBLS0D7N06C
Datasheet:
https://datasheet.lcsc.com/lcsc/2108141230_onsemi-NTBLS0D7N06C_C903210.pdf
Rds(on): 0.75 mΩ
MOSFET 2 Spec
Model: IRFP1405P... |
H: 12V-only (and no 110V/220V) household electrical installation
Power outlets are in 220V/110V in houses for historical reasons (light bulbs and other appliances probably required >100V voltage) but nowadays as:
we use a USB charger 220V->5V for phones, tablets, ...
we use LED bulbs which probably work on low voltag... |
H: What is the proper way to handle a status led when HardFault_Handler or any error is raised?
I am trying to implement a very basic status indicator using an STM32 - Basically I would like to toggle a RED LED when a fault is triggered by the MCU.
Naively I added a toggle LED function in the while loop of the HardFau... |
H: Op-amp square wave to triangle wave converter not working as expected
A follow-up to a similar question from yesterday since the problem I've run into has differed enough to warrant something more than an edit.
I have built an integrator to act as a 5V 32Hz square wave to triangle wave converter.
This is my output... |
H: Help identifying blown power supply line
I have a "330v200" CCTV camera that died some while ago and now that I disassembled it, I discovered that the S4 diode blew up and another component is shorting out.
However, I can't find a schematic for this board and am not sure which components these are.
Above photo fro... |
H: Digital voltmeter reading half the voltage measured with Fluke multimeter
I recently purchased these cheap digital voltmeters from Amazon to display the output of my 2.5 kV HV supply. The HV supply has a dedicated 1/1000 output (0 - 2.5V)for monitoring, which I am trying to measure using the cheap voltmeter.
The vo... |
H: Transistor used in 3 GHz LNA
I've got this 3GHz RF amplifier off ebay, and I'm trying to figure out how it works. I've took the RF shield off, but the markings on the component that I assume is the transistor, are scratched off.
What transistor could have been used here?
Also, how can this thing work with just one ... |
H: Battery with inner resistance circuit problem
"Battery Ba is connected in series with resistor Ra = 2Ω. Battery Bb is connected in series with resistor Rb = 4Ω.
Battery Ba has a voltage of 2V and inner resistance of 1Ω. Bb has a voltage of 1V and inner resistance of 2Ω. The two circuits are connected in parallell i... |
H: How do I calculate a voltage divider with an offset
I've got the following circuit:
simulate this circuit – Schematic created using CircuitLab
By running the simulation I can see that a signal voltage of 3.13 converts to an output of 2.14, but I'm not sure how it got that.
If I simply use the voltage divider and s... |
H: Problem with determining currents in multi-source circuit
I need to solve the circuit shown below:
simulate this circuit – Schematic created using CircuitLab
And here is my attempt.
I'm sure my attempt is wrong here but I'm not really sure why.
I've tried to use the mesh method to determine the currents in the ci... |
H: Current consumption of a tachometer circuit
I am trying to determine how much current this circuit will draw under rest conditions when the Ign- is at roughly 12.5V. Would current run through the blue path? Sourcing from Ign- passing through 330 and 1k ohm resistors and optocoupler to ground?
If this is true it s... |
H: MOSFET's delay of off falling time
I made the circuit using MOSFET.
The falling time when MOSFET is off is too long.
I use the resister 200kohm for test load.
HA17555 output max. current is 200mA and output voltage waveform looked complete squre.
Is it because I use too big resister(200kohm)?
It's my circuit and w... |
H: What is the reason for the current spike in below simulation - at the end when cap voltage drops to zero?
Is the current spike at the end due to the constant power behavioral model?
I have chosen an arbitrary MOSFET for the simulation. The initial current spike disappears when I add a series res to gate.
AI: The vo... |
H: What would be the amplification circuit for PP02 sensor using LM324 pressure sensor?
I am planning to use the PP02 Omron pressure sensor. The user manual of the sensor (Usermanual link) suggests using LMV324 type of instrumentational amplifier with four op amps within in the schematic diagram. The problem with LMV3... |
H: Does a secondary battery always charge to its maximum open circuit voltage?
I'm wondering if secondary batteries have a slight open loop voltage drop after multiple cycles. I found on another forum that a rechargeable battery always has the same open loop voltage after charging, even after lots of cycles, and that ... |
H: Rising edge of signal missing
I've simulatated this circuit with Multisim and obtained an output that seems correct:
I built the same circuit on a breadboard and analyzed it with an oscilloscope:
The output of the real oscilloscope is quite different:
I cant't view the right side of the simulated signal (when it... |
H: What effect does a splitting an audio signal using a y-cable have on that audio signal?
Given a clean instrument-level audio signal of reasonable amplitude passing from point A to point B via a TR/unbalanced cable, what effect would replacing that cable with a TR to dual TR cable running from point A to points B an... |
H: Low Cost andd Urgent H Bridge Need?
I am Creating a H Bridge for 4 x 12V 5A BDC Motor with driving ESP32 Digital Output.
Do I need any Components? because I Must be Small PCB design.
(Maybe I can place 1k Resistor to N Channel MOSFET Gate-Source)
I am Sorry to say (BLDC) it.I Have 4 BDC Motor.
and I Re Upload the ... |
H: Headphone output - what is the function of these resistors going to ground between the decoupling capacitors and headphones
The Korg Monotron Duo synth uses the TPA6111A2 headphone amp. The circuit they use is largely the same as the one from the datasheet - except for R78, the 470ohm resistor going to ground right... |
H: Connecting a Panasonic EVQ-VVD00203B radial encoder to Arduino
I purchased this Panasonic EVQ-VVD00203B radial encoder for an Arduino project, and am having difficulty figuring out out to wire everything up. This is the encoder:
If I understand the schematic correctly, the top is 5V, the bottom left and right are ... |
H: TI Microcontroller Programming Circuit
I am working on designing a pcb that will contain a TI TM4C1231D5PZ microcontroller. I have only ever used a launchpad before for coding, so I do not know how to get my program code onto a microcontroller that is going to be on a pcb. I have looked at multiple resources, inclu... |
H: What is the purpose of this block in UC2854 based PFC circuits?
Below is a snippet from the datasheet of UC2854.
Current transformer senses the input current of PFC. But Rs also does the same. What is the square block shown here?
AI: Looks like a full-wave bridge rectifier which powers the controller IC. The secon... |
H: This is a diode related problem: Assuming the diodes used in the circuit are ideal. Find the current through the resistor
I tried to solve this question but i donot know how to solve. Any one can help?
Assuming the diodes used in the circuit are ideal. Find the current through the resistor.
I asked in foroum and g... |
H: How unsafe is 220V over NEMA 5-15 really?
I'm from the Philippines but the U.S. had a very large influence on our electrical standards. It is especially evident on our electrical sockets.
While all of the sockets in a typical Filipino home are rated 220V, they are all NEMA 5-15 (except for outlets of air-condition... |
H: Why does switching cause power dissipation?
I know that switching logic values causes power dissipation but I could never understand why.
Is it because transistors need to be turned on each time we want to charge/pull up a node and discharge/pull down a node? Is this power consumed by the transistor responsible for... |
H: What is the practical advantage of root locus method in control system engineering?
Recently I learned about the topic.
Decades ago, when no computational power was available for engineers, it was surely helpful in some way. But I do not understand what the advantage is nowadays, because with any math-tool I can co... |
H: Multiple Feedback Band Pass Filter Noise
I designed a multiple feedback filter using the analogue devices filter wizard. I have never designed this type of filter therefore I followed up by reading about it and manually calculating the components. I used arbitrary values to learn the process.
My first filter has Q ... |
H: Unknown SMD Component
I'm trying to find the components of the PCB I have. I have a problem with a 5 pin (SOT23-5) component. Can someone help me with this?
There are version1, version2 and version3 of the PCB and marking codes are AA43, AA44 and AACB respectively.
There is a reset button and an error switch on the... |
H: Why does reverse recovery behavior matter for half bridge bootstrap diode?
I have seen several recommendations in the past to use a schottky bootstrap diode in half bridge drivers, even if the driver integrates a Si junction diode for the purpose, because supposedly the reverse recovery of that diode would be reall... |
H: How do I use a 4x2 ROM to build a 16x4 ROM?
I tried solving it but I'm not sure if I got it right
AI: The outputs do not appear to be correct.
Each pair of ROMs should have an output to each of Y0, Y1, Y2, and Y3.
The first ROM should have one output to Y0, the other to Y1, the second ROM one output to Y2, the othe... |
H: ST-Link doesn't show any data on the serial port
I am working on Nucleo board programming circuits. This board programs like an Arduino, you can compile, run and show data on the serial port. Actually, you can do debugging, too. You just need a USB input for everything.
PROBLEM:
I designed a flight computer that ha... |
H: Can someone explain how this code execution is happening?
module test;
int j;
initial begin
for(j=0;j<3;j=j+1)
fork
$display("inside fork join",j);
join_none
$display(j);
end
endmodule
I am really confused about the values I see in the output. Can someone please explain how it is working.
OUTPU... |
H: Unknown MOSFET symbol
I came across the schematic symbol shown, and I am unsure of what the symbol in the green box is. It looks like a PMOS (yellow box), but it has the line before the gate. Has anyone seen this before?
AI: Those FETs are both nMOS transistors, drawn in the CMOS schematic style. This is the style ... |
H: ESP-WROOM-32 unable to flash with auto-program UART
I just made a custom schematic and PCB with an ESP-WROOM-32 module. The board has a USB-UART chip (CP2102) and an auto-program circuitry to flash firmware without pressing buttons, but it doesn't work: esptool.py stops with
Failed to connect to ESP32: Timed out wa... |
H: In calculating the inductor for a boost converter, where does the power of the voltage source calculate in?
simulate this circuit – Schematic created using CircuitLab
As I am using LTspice to develop different types of dc-dc boost converter topologies and wanted to define the best inductor to use when the voltage ... |
H: AC adapter makes high pitched noise when a notebook is turned off or asleep
When I put my notebook into sleep mode or turn it off the notebook's AC adapter starts making a high pitched noise. When the notebook is on the adapter doesn't make any noises. Could anybody explain why this happens? Is it OK or should I ge... |
H: Why do resistors not result in voltage drop when measuring an open circuit?
I'm very new to electronics and have been trying to learn the basics of electricity as a starting point. The mental model I've developed so far is the standard water/pipes analogy. I.e. voltage is like the pressure, amperage is flow of wate... |
H: Best way to measure microvolt potentials in an electrolyte solution?
I wish to measure microvolt-level fluctuations in a small volume of electrolyte solution, currently saltwater. My existing setup works but has some strange data so I'm hoping someone with more experience can help me sort it out.
Equipment
I'm usin... |
H: What does it mean when there's a minus sign in front of a signal?
What does it mean when there's a minus sign in front of a signal?
For example:
reg [8:0] A;
reg [4:0] B;
wire C;
assign C = -A[4:0] <= B;
What's the meaning of the -A[4:0]?
AI: The unary minus operator - produces the 2-complement of the operand. Tha... |
H: How to generate .ruc file?
I am using RA2A1 MCU for my product and want to use UNIQUE ID code for security purpose and restrict the debugging without ID code.
While flashing from Renesas Flash Programmer (RFP-3.09.01) we required to provide security key which should be store in .ruc file.
My problems is that how to... |
H: How do you determine that a MOSFET needs a gate driver as logic levels are not good for it?
I'm using an IRF620 MOSFET paired with a TC4420 high speed gate driver. Just using the MOSFET by itself with the Arduino does not work properly. It works a lot better and faster with a gate driver.
What I'm confused about i... |
H: MSP430 ADC, using a different memory slot other than MEM0
I'm working with the MSP430Ware Sample Code for a basic ADC on the MSP-EXP430FR5994 development board. On the code, it uses MEM0 and the supporting infrastructure such as flag 0 to convert. The one underneath is my modification; I've used MEM2 and flag 2 to ... |
H: STM32H747 MDMA Transfer Error Address when using FreeRTOS
I'm using the MDMA to communicate with an external flash over QUADSPI.
I have an implementation which works great without FreeRTOS, but when I implement it using FreeRTOS I get Transfer Error Address. I have verified that the RAM address exists in AXI memory... |
H: Drain current spikes when switching on MOSFET with LT1160 driver
I'm designing a control circuit meant to drive a proportional valve. I'm trying to simulate the driver and mosfet side of things in LTspice using the LT1160 half bridge driver and two readily available NMOS transistors. The problem I have is that whil... |
H: Safety check - Is this Amazon PV combiner box labeled wrong? 15A Vs 32A - 500V vs 1000V
I'm currently working on a solar circuit. I wanted to protect my internal systems from my panels in the event of a surge. I purchased a PV combiner box from Amazon - link to product.
It claims to be a four-string box with 15A DC... |
H: How do Li-Ion batteries detect their temperatures?
I know that Li-Ion batteries have specific charging temperature ranges... but how do they detect when they're too hot/cold to charge and prevent the charger from working?
Secondary question: a component on the board a Li-Ion battery is connected to just blows up. T... |
H: Escape room: How how to switch between lamps?
I’m building an escape room and have a little puzzle here…
There is a lamp normally turned on when the people enter the room. When they solve a puzzle by putting a magnet in the correct place, I want the normal light to go off and a blacklight to come on.
I’m planning t... |
H: How can I characterize this voltage source?
This is my first attempt at trying to characterize a voltage source.
The voltage source is a 99.8% magnesium rod (10mm diam., 160mm in length) its length wrapped by paper 1mm in thickness then its length once again wound with 4 meters 3k carbon filament. Its electrolyte ... |
H: SystemVerilog ring oscillator simulation with different delays
I am currently encountering issues with my ring oscillator simulation in SystemVerilog, which I cannot explain.
Toolchain:
╰─○ iverilog -V
Icarus Verilog version 11.0 (stable) ()
╰─○ vvp -V
Icarus Verilog runtime version 11.0 (stable) ()
ring_oscillato... |
H: What are these types of coin cell contacts called?
I am working on a low-profile product that will be powered by a coin cell. I've seen some products that use coin cell contacts that allow the battery to be beside the PCB, rather than on top of it. This saves Z height, and is desirable for my application. Note that... |
H: I am trying to find equations for i1(t) and i2(t) using laplace transform for this step input
The place that I am confused is that for \$i_1(t)\$ im trying to use the loop method to develop the first equation which is
$$v(t)-L_1\frac{di}{dt}-(R_1+R_2)i_1(t)=0$$
and then use \$i_2(t)\$ for the second loop
$$R_3i_2(... |
H: What is the name for this connector socket pin configuration?
Does anyone recognize this female socket pin layout as a standard design of any kind?
I was looking at 5-pin CB Radio Microphone sockets, and they are similar, but not the same layout.
Also, the ones I saw did not have the "sixth" connector pin in the mi... |
H: Need help with simulation of three-phase active rectifier on LTSPICE
I have already successfully simulated a three-phase rectifier on simulink. However, I wish to implement the same on LTspice because I would have liked to see the effect of using non-ideal components. In order to make it easier and avoid whole cont... |
H: What is the result of wiring an electrolytic cap in series with a ceramic when parallel was intended?
FINAL UPDATE A reassessment of my power consumption has led me to the solution to all of my problems. I picked up a 5V, 5A power supply (giving me plenty of overhead), reassembled my project, and it is now working ... |
H: What type of connector is this and how do you safely disconnect it?
While disassembling a Samsung Plasma TV, I've come across this connector labelled "High Voltage" on the power supply PCB.
I'm not sure how to remove it from the PCB. It seems to have two tabs on the side, but I'm not sure how to use them (if at all... |
H: What is the actual purpose of pad via library in Altium Designer?
The Altium Designer has schematic symbol library and PCB footprint library. I understand both of these. However, there is a third one called pad via library.
Pad is the exposed copper on PCB where a component is soldered. It could be a SMT pad or a t... |
H: Why does Japan use 100V AC as opposed to 120 or 230V, and why are many of their plugs ungrounded?
I don't live in Japan but I have noticed this interesting phenomenon when it comes to their electronics.
I'm buying a PC-9800 and because it remained isolated in Japan its power supply is only rated at 100V. If I am to... |
H: Is there a way of converting easily binary numbers to its ASCII equivalent?
I have this digital circuit design problem where we receive two two-digits numbers in ASCII, I have to convert them to binary, add them, and the result I have to encode it to ASCII again.
I actually did all the ASCII to binary and the addit... |
H: Rise time and clock frequency: when does it start biting me?
I have spent quite a bit of time reading (mostly the questions and answers on here) about rise times of square waves and how they can cause transmission line effects (reflection, ringing, etc.).
Everyone seems to be talking about rules of thumbs about whe... |
H: Why do we say that the load impedance must be equal to the characteristic impedance to have adaptation/maximum power transfer?
If impedance matching requires conjugate complex matching of the transmission line to the generator impedance (for optimal power transfer), why do we say that the load impedance must be equ... |
H: Transfer function for Sallen-Key notch filter
How can I find the transfer function H(s) of the following circuit by using impedance of the circuit?
Should I instead do it by nodal analysis?
AI: The exact "no shortcut" way (by assuming the opamp works ideally) is to replace the opamp and its feedback resistors with ... |
H: Control power through a resistive load from a DC source and achieve low current peaks
I want to control the power through a resistive load from a DC source and achieve low current peaks. The use case is 0-1000VDC and 0-15kW (not for the entire voltage range). All other parameters and circuit design are changeable.
... |
H: High side power switch IC drops 0.5V when loaded
I setup a circuit shown in AP2411 data sheet on a solder-less test board and connected the output to 30 ohm resistor to ground to simulate about 100mA of current. Input voltage is 3.3V from a lab power supply and looks clean on a scope. Output voltage when the resist... |
H: Diode and resistor in parallel
I was recently investigating a model of a circuit in which there is a resistor in parallel with a forward-biased diode.
Why is the current passing through the resistor dictated solely by the forward voltage of the diode? Why doesn't the resistor 'see' the supply voltage?
For reference... |
H: Why do some electronics have two power/ground pins?
I was looking at the BMP280 temperature/pressure sensor schematics on KiCAD, and I saw that it has two power pins, and two ground pins. Why is that?
Please let me know if more information is needed on this part.
AI: The GND pins are largely the same, they are dupl... |
H: Why use two transistors driving LEDs when one would work?
Recently received a small PCB from China with a simple LED driving setup (12v input).
I spent some time probing it out and reverse engineered this schematic;
I'm trying to understand why they designed it so that this uses 2 transistors (granted my understan... |
H: H-bridge gate driver for an ESP32
I used an H-bridge for 12V 10A brushless DC motor. The motor must run in both directions.
ESP32 ----- Multiplexer Circuit ---- Gate Driver ---- H Bridge ---- Motor
I have a few questions.
Am I using too many components for a motor like this?
Is the 10k resistors necessary for the... |
H: LED flasher circuit: unexpected behaviour
I am a beginner so bear with me.
I have attempted to design an LED flasher circuit but it gives unexpected behaviour.
Diagram:
When I apply the 9V DC voltage, the LED stays on for about half a second then turns off and will not turn on again until I discharge the capacitor... |
H: Energy cost conversion
If electricity costs $0.06 per kilowatt-hour and is used for electric heating with an efficiency of 100%, what is the equivalent price of natural gas per gigajoule if it can be burned with an efficiency of 80%?
(A) $8.00/GJ (B) $13.30/GJ
(C) $15.10/GJ (D) $21.20/GJ
(E) $24.30/GJ
The Book Answ... |
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