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Transformer ratio of a transformer that connects a generator to a MV grid?

Inside my one-line diagram in which I am studying some properties of the medium voltage grid, I want to connect a generator to the MV busbar to study the hosting capacity. Therefore there is not a ...
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-2 votes
0 answers
89 views

What is the benefit of this capacitor?

As I know capacitor in DC circuit is not let current go through, and also it is just charging for a while and it becomes like open circuit, so what is the benefit of it?
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6 votes
1 answer
179 views

XKCD 356 puzzle

I was reading XKCD and saw this comic: Turns out it works, and have been thinking about this for an hour and have gotten nowhere. My first thought was to find the resistance of all paths of length ...
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1 vote
2 answers
43 views

Finding the voltage available at the terminals of the battery in a circuit with parallel resistors

I have four different resistors connected in parallel to a \$24.0 \ \text{V}\$ battery with internal resistance of \$0.500 \ \Omega\$. The resistor values are \$10.0 \ \Omega\$,\$15.0 \ \Omega\$, \$30....
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2 votes
0 answers
43 views

Linear Analog Optocoupler Arrangements

For optocouplers with a second photodiode for feedback for linearization, what is the functional difference between the two positive input stage configurations below? simulate this circuit – ...
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0 votes
0 answers
39 views

Polarized DC breaker between the battery and the inverter [closed]

I'm setting up a 5kW off grid solar system and planning to install a 125A polarized Dc breaker in between the 5kWh lifepo4 battery and the MPPT inverter. I heard that a polarized breaker isn't ...
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0 votes
1 answer
26 views

External RC oscillator fuse programmed instead of external crystal fuse

Is there anyway to revive an Atmega8A? avrdude says avrdude: error: program enable: target doesn't answer. 1 ever since I ...
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  • 798
0 votes
1 answer
66 views

How to switch a SIM800L modem on/off with an ESP32-CAM, without a relay?

I would like to turn a SIM800L modem on/off (to save battery), controlled with GPIO 16 on an ESP32-CAM, without a relay. It was working OK with an electromagnetic relay, but I'd like to avoid the ...
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  • 109
2 votes
1 answer
60 views

Off-grid computing

I am designing the electrical system for a school bus to tiny home conversion (skoolie, by jargon.) The current iteration is entirely solar powered, somewhere around 2640 W in panels, and likely 1000 ...
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0 votes
0 answers
21 views

What is a common non-SMT audio codec module with USB interface? [closed]

I am looking for a relatively cheap, audio codec with USB interface. Only thing I could find was PCM- series device from Texas Instruments, but they are too tiny. Also, I have 2 more related questions:...
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1 vote
1 answer
38 views

Possible damage to LED or driver from PWM power source and flickering? [closed]

I recently upgraded my car's headlamps from halogen to LED bulbs with integrated drivers (I believe this is the specific product), and I discovered that they flicker when the lights are on in "...
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  • 111
0 votes
1 answer
49 views

Calculating AC Unit Watts

I'm trying to calculate the watts used from my AC unit. Below I am including my sticker label that's on the AC Unit along with a electrical data sheet I found online for my model. So far this is ...
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0 votes
0 answers
36 views

Split-phase wiring [closed]

Please see wiring diagrams on side for single phase 3-wire motor. A new motor has connections labeled 1 and 2 and 4. My elderly mother owns a restaurant, and her commercial ice maker auger motor has ...
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3 votes
1 answer
85 views

Circuit that switches on at 4V and off at 3V

I'm new to circuit design so please forgive any misstatements. I'm wanting to create a circuit that turns on a device (mini water pump) when a voltage hits 4V or higher and turns off the same device ...
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-2 votes
0 answers
34 views

3 Floor DC Elevator Project [closed]

I'm using SG90 servos to open and close doors on each floor of my elevator. The Elevator will be controlled by PLC. What do I need in terms of circuits to run the servos?
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  • 1
0 votes
0 answers
38 views

Current transformer wire issues

I would greatly appreciate some advice regarding twisted pair conductors for a current transformer. So, according to the manufacturer, whose equipment I am installing, I need to connect 10 AWG, ...
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  • 13
0 votes
0 answers
42 views

How is the circuit behaving during positive and negative half cycles?

Took this from a IEEE paper. I am confused with converter configuration. During the positive half cycle of supply, wouldn't the diode D1 be forward biased and D2 be reverse biased? IEEE PAPER
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0 votes
1 answer
66 views

MC24C08 EEPROM Write Cycles

What is the MC24C08 maximum write cycle count for a given bit or for a given byte? It doesn't say so on the datasheet, and I get conflicting answers when I look up this question for other EEPROMs (...
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  • 47
2 votes
2 answers
72 views

Differential capacitive transducer

I would like to design a differential capacitive transducer to measure the capacitance change in an accelerometer. I cant seem to understand, how to demodulate the signal and keep the actual DC value....
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1 vote
3 answers
178 views

Why does this circuit produce a triangle wave?

EDIT: Op amp is a UA741CP I built a simple square wave generator on a breadboard as shown in the picture below. C = 1 μF R1 = 1k R2 = 10k R3 = 10k Supply voltages are +/- 12V The circuit produces a ...
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3 votes
2 answers
124 views

Why do I read 20 microamperes instead of 5?

I am trying to do this experiment, but I can't read the current Ib. Note that the multimeter I use in this experiment is very sensitive. I don't know much about BJT transistors, so it might be an ...
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0 votes
1 answer
45 views

Converting measured S-parameter to Z-parameter does not match the Z-parameters measured on the same circuit

I have measured the S-parameters for a 4 port circuit. For a certain frequency those values are: ...
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  • 1
0 votes
3 answers
131 views

Connect different "blinking LEDs" in parallel

I have a simple motor and two LED toy with different color leds: LED D1 is blue blinking listed as 30mA/3V/0.09W (osub5x31a), LED D2 is red blinking listed as 20mA/3V/0.06W (OSHR5X31A). Battery is ...
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  • 109
0 votes
0 answers
25 views

Inverter MOSFET Snubber: RC or Schottky diode?

I've researched this question and found a lot of theory, but not much practical anecdotal experience. I would like to hear from those with physical knowledge of this. I've constructed a transformer ...
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0 votes
0 answers
32 views

The relation between BLDCs the same speed and the different load [closed]

OUTLINE:After increasing different loads, why does the brushless DC motor always reach the speed under the corresponding voltage? This experiment does not use the speed closed loop. Details: BLDC ...
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0 votes
0 answers
43 views

How can I step down 24V to 5.5V and 3.3V with separate grounds?

I have a 24VDC 4A input that I need to step down to both 5VDC and 3.3VDC, but I need the 24V ground plane to be separate (isolated) from the 5V and 3.3V plane (these can have a shared ground). What ...
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-2 votes
2 answers
60 views

Why is the bridge rectifier circuit widely used to make power supplies?

Why is the bridge rectifier circuit widely used to make power supplies? Which is better - a bridge rectifier with capacitor or without capacitor?
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-1 votes
0 answers
34 views

Chip replacement suggestion [closed]

I am fixing a SNES cartridge and I suspect the RAM chip may be defective. The chip is an SN74LS139N by Texas Instruments. Are there any datasheet repositories? How do you read a datasheet? How do you ...
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  • 149
3 votes
2 answers
181 views

I do not understand this polarity symbol with 3 circles: positive, round, negative, and no lines

I am trying to figure out what is the right polarity of a power adapter for a small practice amplifier. I know it is 9 VDC and I figured out the size of the plug and I know the wattage needed. I do ...
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0 votes
0 answers
22 views

DC leakage in single and three-phase rectifier (Electric vehicle chargers)

It seems that the IEC 61851-1 standard ask for a device monitoring DC earth current for any EV charging station, either single or three phases. What I'm wondering, is, which topology of charger, or ...
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  • 21
5 votes
2 answers
135 views

What prevents old (low current) USB cables from catching fire if used to Quick Charge modern devices (at high-current)?

Let's say I have A very old Micro-USB cable. It's USB 2.0 and rated for a max current of 5V, 0.5A (2.5W). A modern, power-thirsty, quick-charging tablet that charges over micro-USB at a max of 100W. ...
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0 votes
1 answer
70 views

How does a system measure the speed of a servo motor using brushes on the commutator?

I have a servo motor with 4 brushes on its commutator. The motor is connected to a controller that enables the user to control the speed and at the same time it has an analog RPM meter which most ...
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2 votes
0 answers
35 views

Current Direction and Voltage Polarity in Capacitor/Inductor Circuits

I believe that this question may be simple for those with a little more experience, but it is still puzzling me. Studying capacitance/inductance, I understand that the capacitor in the DC case behaves ...
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1 vote
1 answer
50 views

Graphing modes of BJT

Suppose we have this Ic vs Vce graph of a BJT transistor I have been taught this graph is applicable for this BJT transistor configuration. simulate this circuit – Schematic created using ...
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1 vote
1 answer
68 views

Finding resistance for parallel resistors: how is my reasoning incorrect, and what is the correct reasoning?

I have the following circuit: The voltmeter \$V_1\$ measures the voltage drop across the \$9.00 \ \Omega\$ resistor and has a reading of \$4.50 \ \text{V}\$. The reading on ammeter \$A_1\$ is \$I_1 =...
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  • 1,201
0 votes
0 answers
22 views

SVPWM control on a BLDC Motor: No-load current is too high

I'm having issues running SVPWM control on a 2 pole-pairs. I'm using a Micronas HVC4223F with a 12V motor Faulhauber 2232BX4 with integrated Hall sensors. My card's half-bridges have over-current ...
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1 vote
0 answers
63 views

Frequency Response of Antennas

Electromagnetics and antennas are not my main area of expertise. However, I have a specific question about antennas that I want to get right in order to make sure my signal processing is right. What ...
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  • 11
2 votes
0 answers
19 views

DebugMon_Handler not triggered even after configuring DWT (Data Watchpoint and Trace) to look for memory writes

Can anyone advise why my actions described below do not work?: I have been trying to run the code snippet from the post Can Cortex M4 data watchpoint trigger an interrupt without a debugger? on(...
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1 vote
1 answer
112 views

Why this grounding scheme?

The NASA technical book about grounding in spacecraft (NASA-HDBK-4001) (I believe the question may be relevant for any other terrestrial application) mentions this grounding scheme for subsystems: ...
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  • 1,052
4 votes
1 answer
314 views

What is the meaning of temperature characteristics in capacitor datasheet?

I found a datasheet for a medium voltage ceramic capacitor in door knob form factor. I'm not familiar with one of the stated characteristics. Specifically, the temperature characteristics: +22/-33%....
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0 votes
3 answers
61 views

Altium designer PCB - Strange and confusing symbols everywhere (From DRC - Design Rule Checker)

I'm starting to learn Altium Designer, and I have this on my PCB screen: I've tried several things, but nothing works. Here is the same image, I just moved the components away: Can someone explain ...
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  • 43
0 votes
0 answers
17 views

How do you combine state space models of a large power circuit having control circuit?

I am trying to model a hybrid network using state-space representation. How do I start? I have modeled the individual circuit figures. but I don't know how to proceed with combining the control and ...
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  • 1
0 votes
0 answers
27 views

The problem with sensitivity time controlled (STC) based on pin diode

I'm using sensitivity time controlled (STC) pin diodes of PN:MPP 4201A-206 for our applications. Our operating frequency from 1300 MHz to 1400 MHz. See the schematic diagram below. As device ...
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2 votes
3 answers
249 views

DC motor speed control without changing the voltage

My truck's (2013 F150) blower motor lets you control its speed using a dial on the dash. I assumed the dash dial change the resistance of the circuit the blower motor was on, but when I took voltage ...
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  • 125
0 votes
1 answer
34 views

Motor voltage spike

The circuit below is used as a relay in order to cut-off the common ground C- and Motor-. In my system, the m otor driver (Motor+,Motor-) is connected in parallel with the supercapacitors (C+,C-.) ...
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8 votes
3 answers
2k views

How long can a micro SD card hold data without being powered? [closed]

I lost a micro SD card few years ego, and I'm worried that someone may find it and misuse the data stored in it. How long can a micro SD card keeps the data without being powered, ignoring other ...
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10 votes
6 answers
1k views

How does current flow in multiple vias?

How does current travel in multiple vias from one layer to other? For example, we connect four vias, each of which has a limit of 1.3A each from power plane to sink device. If the sink draws 4A of ...
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  • 395
2 votes
1 answer
33 views

ADS1113 ADC saturation at 0 Volts while sampling bipolar signal

I'm using a ADS1113 delta-sigma 16-bit ADC to sample a bipolar signal from a force sensor at 50Hz, and I have found a weird phenomenon. When the signal negative or positive, there is no issue, but ...
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  • 23
2 votes
1 answer
26 views

What is the link between conjugate matching efficiency and amplifier efficiency?

In the design of a class AB amplifier, there is part of the understanding that I miss. It is well-known that the maximum power transfer is achieved when the load impedance is the complex conjugate of ...
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-1 votes
0 answers
78 views

Help me to find out resistor for my ceiling fan board [closed]

I am moding my ceiling fan into a remote control. The fan has only 3 wires and changes the speed of a capacitor like this I buy a remote board like this I have already had the success of moding 3 ...
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  • 11

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