All Questions
195,224
questions
3
votes
1
answer
98
views
Identifying this coax connector?
Circular 1-pin coax connector. Trying to identify so I can buy a new socket for it.
- 131
1
vote
1
answer
18
views
Is it possible to multiplex thermistors for multiple cell battery configurations for the BQ25756 or other JEITA charge ICs for spaced apart cells?
I'm trying to figure out how to safely implement fast charging using the BQ25756 with a most likely 2s (though up to 4s is possible) layout of physically spaced out cells.
I haven't fully decided on ...
0
votes
1
answer
32
views
Does the RCD go before or after the MCB?
I am going to connect a 4 pole RCD and MCB to the input of a power supply. Which one should I connect first, the RCD or the MCB? I have seen them connected both ways.
- 1
1
vote
1
answer
39
views
Multisim simulation insight
I want to simulate an AC circuit in multisim. I would like hints or articles on how to simulate complex-valued impedance, for example this circuit:
I don't have an option in multisim 12.0 , to have a ...
2
votes
2
answers
46
views
I2C BME688 Read Request Sent, but no data received
As the title suggests, im interfacing with the BME688 using I2C. The signal I captured using my logic analyzer is shown below. The slave address is 0x76 and register address im trying to read is 0xD0. ...
- 21
0
votes
1
answer
32
views
What is the direct coupling problem which differential amplifiers help avert?
The discussion below comes from Chapter 3.5 of Analysis and Design of Analog Integrated Circuits by Gray, Hurst, Meyer, and Lewis.
In particular, I do not follow what is meant when they write
This ...
- 309
2
votes
3
answers
113
views
How does common ground work in this Arduino project?
I just saw a video on YouTube explaining common ground with an Arduino, leading to some headaches. I'm a beginner, so I apologize for a primitive question and a primitive description.
In the video, he ...
- 21
0
votes
0
answers
37
views
Reduce noise coming from DC brushless fan
First of all, I'm an amateur when it comes to electronics so thanks for your patience!
I have added a fan on a sound processor which tends to overheat but then I discovered I can hear the fan on the ...
2
votes
2
answers
68
views
BJT Amplifier simulated gain is only around 80% of calculated gain. Why is this and how to improve calculation vs simulation accuracy?
I'm trying to design a CE BJT amplifier in Multisim with 100mVp 1kHz input, and target gain of around -208.8. Starting from my choice of Vcc = 50V and Ic(DC) = 15mA, here is the design I came up with:
...
- 23
1
vote
0
answers
50
views
Mix of power supplies
I am struggling to understand what happens when two power supplies are connected:
Both supplies build a whole circuit, the rest of the second supply is left out for simplification
Both power supplies ...
- 29
1
vote
2
answers
244
views
How to write the equation for the input side of a JFET?
I have been reading about the voltage gain of JFET, but I am unable to understand how to write the equation for the input side. Can somebody explain the method to write the equation for the input ...
- 153
3
votes
1
answer
80
views
Sign Modulator - Class Project [closed]
I need to simulate a specific circuit, and I'm running out of time, so please someone can tell me what I am doing wrong?
I think I have this part correct:
Here starts the problems, I don't know how ...
- 31
2
votes
1
answer
98
views
MAX7221 with multiple LEDs per point
I am using a MAX7219/MAX7221 chip in a keyboard design in order to light up the individual keys. The keyboard is going to have exactly 64 keys so with the 8x8 matrix the chip handles I will be able to ...
- 191
0
votes
1
answer
22
views
PL230 DMA & PL022 SPI transmit only 9 bytes
I am trying to implement SPI+DMA on W7500. The chip has a PL230 DMA and PL022 SPI (with 8 level FIFOs). First I just want to transmit N bytes using DMA basic mode. On the pins I only see 9 bytes (or ...
- 8,901
-1
votes
0
answers
39
views
mcs-51 interrupt function executes twice while a signal in [closed]
I make a counter with mcs-51 and photosensitive sensor, use an LED segment display to display the number.
my code is
...
- 1
0
votes
1
answer
28
views
HDMI Termination analysis
Recently came across one ULX FPGA board add-on. HDMI TMDS signals are terminating on this board. I am unable to understand why highlighted resistors are used for. Seems like some sort of voltage ...
1
vote
1
answer
79
views
Where to place an LED to indicate the charging of a battery via a solar panel?
See the attached circuit diagram and PCB design. All I'd like to do is have a very small LED turn on when the panel is charging the battery.
Circuit description: Q1, a PNP transistor ensures that when ...
- 113
0
votes
0
answers
37
views
A varying-frequency control flyback rectifier for constant current LED driving in boundary-conduction mode [closed]
I would like to build a constant current LED driver using a flyback converter in boundary conduction mode.
What are the equations required to obtain the inductance and capacitance values in the ...
- 1
0
votes
0
answers
29
views
Can I load a transmission line to more than 10x surge impedance loading?
Assuming that I use a high temperature low sag line that can withstand 210°C CIGRE. These lines have a thermal limit around 20x surge impedance loading (SIL). If I use such line:
Do I still need to ...
-1
votes
0
answers
48
views
Aircraft Simulator Intercom [closed]
I'm new in trying out electronic projects and I am an aviation enthusiasts. I'm trying to build my own "Intercom" system for my simulator that is connected to a PC but I am lack in ...
0
votes
0
answers
91
views
Can opamp directly drive the MOSFETs?
There is a 12 V DC source. I am also generating a 10 V source from it. The output is connected to a battery. This is basically a battery charging and cutoff circuit. The charging part is working fine ...
0
votes
2
answers
45
views
Unity Gain Buffer Output Impedance
First time here. I'm not an engineer so please pardon my lack of technical expertise. Thanks in advance for your help!
Here's is the circuit in question:
I've been told that R5 (10K) sets the ...
- 1
0
votes
2
answers
64
views
Circuit that outputs signal A when AC sine is positive and signal B when AC sine is negative
I need help designing a circuit that outputs Signal A high when AC sine wave is positive and Signal B high when the sine wave is negative. It's part of a larger project that cycles power in a ...
- 13
1
vote
0
answers
22
views
How to improve the electromagnetic field in this HFSS design for microstrip patch antenna?
[electromagnetic field for my patch antenna design]
The thing is I am trying to design a patch that resonates at four different frequencies with the dimensions of 13mm x 13mm x 0.25mm. I am actually ...
-1
votes
0
answers
8
views
connecting a tasi ta612c USB to laptop [closed]
how can i connect a temperature thermocouple to the laptop, is a Tasi ta612c data logger, ive downloaded the software, but when i plug the USB it doesn't show on the laptop
0
votes
0
answers
28
views
HDMI termination board
We are trying to make one HDMI termination board. This board will plug-in into my motherboard and emulate 1080p display. I want to use this termination board for EMC chamber testing of the motherboard ...
0
votes
0
answers
42
views
Why doesn't my JK FlipFlop built in Logisim work?
My JK Flip Flop in Logisim doesn't work and it shows the oscillation apparent error and I can't figure out why. I do remember seeing a similar question where one of the answers claimed that a circuit ...
0
votes
0
answers
57
views
How is clearance and creepage considered in this case? [duplicate]
I'm making a high voltage PCB where there are 2 grounds - one is HV ground (HV-) and the other is the microcontroller ground which is isolated. HV+ is at 100VDC. How do I consider the clearances and ...
- 47
1
vote
2
answers
120
views
How long would it take a 400 W solar panel to charge a 28 kWh EV battery?
I'm located in The Gambia which is almost on the equator. We get over 11 hours of sunlight on Dec. 21st. Being a tiny country, daily travel is minimal, at most, maybe 28 km. If I place a 400 watt ...
- 13
7
votes
2
answers
828
views
What's the point of memory compilers like OpenRAM or Synopsys Memory Compiler?
I am relatively new to ASIC design. I have experience at RTL design level and have successfully developed designs on FPGA's, but the ASIC world is still new to me. I don't have access to commercial ...
- 71
0
votes
1
answer
30
views
Speaker and buzzer sound levels issues
I have designed two test boards to evaluate the sound levels of several speakers and buzzers. While the buzzers are functioning as expected, the speakers are producing sound levels that are ...
- 15
-1
votes
0
answers
22
views
Branch current analysis [closed]
How to solve this question anybody can help me........
0
votes
1
answer
94
views
Was my Arduino Uno killed by ground loops?
Important context:
A couple weeks ago, I ported a C based nqueens program I found online to the Arduino Uno.
Today, and I'm all like "LETS OVERCLOCK THE NQUEENS ARDUINO!!!" Ugh.
I swapped ...
3
votes
1
answer
222
views
Shielding bottom of PCB in THT design
I'm designing a PCB where I could use one layer as massive groundplane and shield. Do I have to make some form of shield for THT part pins, or are they small enough to not pickup a lot of ...
- 31
0
votes
1
answer
53
views
Charge leakage in home appliances [closed]
I have a basic question which isn't cleared through answers found.
We experience a slight electric shock in case of home appliances like fridge, oven etc. when we touch the metallic parts of those ...
5
votes
2
answers
83
views
How to find the tolerance on the output of an op amp circuit?
I'm trying to determine the accuracy of the DC circuit below but I am unsure how to account for input bias currents, input offset voltages, open loop output impedance, input resistance and open/closed ...
- 51
-3
votes
0
answers
44
views
Energy Harvesting - General Requirements [closed]
Generally speaking - what ideal parameters would you want for an energy harvesting device specifically for the following :
Max Power output?
Output Voltage variation?
Size of energy reservour?
Is ...
- 57
2
votes
1
answer
82
views
Do you put a ferrite bead on both the positive voltage and GND trace?
I'm designing some basic DC power filtering for a very simple PCB. Do ferrite beads go on BOTH the positive voltage trace AND the GND trace, or should GND be completely free?
- 221
2
votes
1
answer
39
views
Properly Charging NiMH Batteries that Have been Stored for Too Long
For a Robotics Project, I've purchased two equal NiMH batteries, seven months ago.
PRODUCT = NiMH Battery 12V 3000mAh XT30 Connector [MH-FC] 20A Fuse 12-20
LINK TO PRODUCT = LINK
There is no ...
- 21
1
vote
1
answer
33
views
LED brightness control with limit and LDR
I made a digital circuit that follows the signal of an LDR, setting on a LED when the voltage is grater than the limit. It also changes the intensity of the brightness as the voltage rises and fall, ...
- 11
0
votes
0
answers
14
views
Load cell / distance sensor [closed]
I'm looking for a device and/or software that will allow me to graph force VS distance using a load cell and a distance sensor.
Ideally, I want to use an arbor press to compress a spring and measure ...
3
votes
1
answer
80
views
What would be a good way to program an MCU in a mid sized (few hundred) batch?
I'm looking to have a few hundred boards made and they all have an MCU on them, that will need programming. With large scale production, it seems the way to go is usually programming the IC/MCU before ...
- 31
0
votes
1
answer
41
views
Can my smartphone's microphones get damaged by recording loud sounds? [closed]
I recorded some songs with my Android phone from another phone at maximum volume.
Will this damage my Android microphones?
- 1
1
vote
3
answers
120
views
Do I need a resistor in circuit when charging capacitors?
I want to charge a group of capacitors whose total equivalent capacitance is \$ 705 \:\mu F\$ and whose equivalent series resistance is on the order of \$10^{-2} \:\Omega\$. I am trying to charge them ...
- 11
0
votes
1
answer
80
views
Cannot isolate Raspberry Pi from the other circuit using optocoupler. Why not?
I'm sending data (Tx1-D) and command (Tx2-C) communication from Raspberry Pi 3 at baud rate 115200. I tried to isolate the RPi from the other circuits by using optocoupler as in the diagram but it ...
- 5
0
votes
1
answer
40
views
FTDI FT234XD not recognized
I designed a PCB that incorporates FT234XD (Datasheet) USB-UART converter but no matter what I tried, I couldn't get it working. Host computers does not even react let alone give an error so it's ...
- 159
0
votes
1
answer
29
views
Switch to handle two inputs and switch between two sets of two outputs (guitar amp send and return switch)
I am looking to build a simple box, for fun, to switch the send and return signals from a guitar amplifier effects loop between two different amplifiers, depending on which amp I am using at the time.
...
- 103
0
votes
1
answer
36
views
Transfer large data over CANopen [closed]
I am new to integration and implementaion of CANopen, so i would like some suggestions on one of the feats i am trying to achieve.
I am trying to send sensor data over the network cyclically every ...
0
votes
2
answers
59
views
163 A - 400 Hz CT Testing For Aviation Generator Application
What power supply equipment could I use to provide a 400 Hz, 163 A rms supply to support the testing of a wound Current Transformer installed to an aircraft power generator?
The test requirements are ...
- 1
0
votes
3
answers
136
views
Easiest way to get highly-accurate frequency reference?
I just want to check the calibration of my frequency counter, so anything constant under 250 MHz would work(?)
Mains are synced to atomic clocks, to maintain wall clock accuracy, but only ...
- 28.7k