All Questions

116,704 questions
7 views

How fail-safe is \n\r as stop bytes?

In my UART communication I need to know the start byte and the stop byte of the message sent. The start byte is easy but the stop byte, not so much. I have implemented two stop bytes at the end of my ...
8 views

Neutral wiring in residential homes

I understand from the diagram below that the neutral wire provides a return path to complete the circuit so that the current can flow. But once the current goes back to the distribution transformer, ...
8 views

I am planning on building a 4 series battery pack using 18650 3500mAh batteries. I bought the batteries and this 2 amp charger, but for the life of me I cannot find a compatible BMS board. https://...
13 views

How an electrical grid works?

I am an electrical power student but my concepts are very weak. I want to know how the electricity that is generated is transmitted, distributed and utilized. How much voltage is produced on a ...
7 views

Limiting current in a NCP3020A switched DC/DC buck converter

I want to design a 12VDC to 5VDC converter using a NCP3020A. As my application has nothing special, I should follow the topology of the Typical Application circuit, and reapply the formulas in the ...
17 views

Does solar pannel develop current

I would like to know weather solar pannels and battery generate current the same way
17 views

Low power electromagnet for a light small load

We have a 3x3mm circular thin plate,this is made by copper,aluminium similar materials and thickness of the plate is 1mm, a very light and small piece of metal. For up to lift this plate about 2mm(...
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Comment on Git code for ACIM VFD drive

I am new in the field of Motor Drive. While searching for a sample code to get jump start I found this impressive repo on git: GIT Repo for VFD Drive There is not much help given there. I wonder if ...
15 views

Implementing UART flow control in microcontroller

I'm communicating data from my microcontroller (Teensy) to my Bluetooth module (nRFx) which is also a microcontroller that I can program. I use UART to communicate the data I want to send over ...
19 views

Not functioning Class-D Stereo Amplifier circuit

I am connecting a circuit for Texas Instruments TPA3125D2 Class-D Aplifier. Datasheet here: http://www.ti.com/lit/gpn/tpa3125d2 The circuit design is here: The problem is, that ALL I get, is some ...
5 views

I'm new to the Tiva Platform for the past two days I'm trying to read data from bme280's data registers. However, it always returns a 0(I2C bus not working). So far I've tried using this sensor with ...
26 views

When using SWD interface, is the reset pin necessary?

When using the SWD interface, is the reset pin is necessary? In JTAG, there are 5 pins TCK, TMS, TDO, TDI and RST but usually SWD is a 2 wire interface. So I am confused about this.
13 views

atmega128 doesnt return from function even if Extended.M103 fuse bit is disabled

Hi I know i should n't be using atmega128 but it will take some time to replace besides there are 100's of PCB already in making. my problem is, if you look at the main() i have declared each function ...
22 views

Flipflop value a long time after startup

After power up in an ASIC, is it save to assume that all flipflops are in a stable state ('0' or '1')? I do not care in which stable state they are, but it is crucial that all metastability has ...
19 views

How does the voltage remain constant at secondary side of flyback SMPS when secondary current is decreasing linearly with time?

Continous Mode of Flyback SMPS
9 views

Series-feed patch antenna, pattern-S11 tradeoff with element spaces

I've simulated series feed antenna with 5 element. after tuning spaces between patches I have achieved nice broad side pattern normal to antenna feed lines with s11=-6.5dB. But if I subtract 0.8mm ...
19 views

Can I take the voltage across diode to be same as the input voltage in a limiting circuit?

My doubt is a trivial one, can I take VD1 and VD2 to be V1? If so doing that doesn't make sense to me 'cause when the current flows VD1 is certainly not equal to V1. This isn't a Homework question, ...
20 views

Can anybody please explain what is race condition in jk flipflop?

I'm studying about jk flipflop, there I got race condition. I have gone through many subject sources but I didn't get any clarity about it. Can anyone please explain about race condition in detail ...
34 views

I have a 2 A 12 V regulated power supply and I want to use it to emulate a 9 V battery for a breadboard

I have a 2 amp 12 volt regulated power supply and I want to use it to emulate a 9 volt battery for a breadboard. However, I need to protect the power source and the components used in my breadboard ...
12 views

common source pole calculation vs. simulation

I would like to compare my pole simulation results to my hand calculations, I'm receiving quite a big error. when simulating a Common Source stage without output capacitance load there is a big ...
19 views

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Buck converter design using MCP1630V

I have already designed a buck converter with the following specifications using an MCP19035: Vin=14V, Vout=1.8V, Fc=63kHz(Crossover frequency), Vref=0.6V, Iout=10A step load High IOH=7.5A step ...
6 views

PIC SPI PPS and pin selection

I need to communicate with a Dual DAC : DAC , by using SPI. I use PIC18F26K83. It is the first time I use SPI so I have some very basic questions: So I have seen that SPI uses 3 PINS: SPI Data Pin, ...
19 views

What's the conduction angle for a full wave rectifier with filter capacitor?

Shouldn't the conduction angle for a full wave rectifier with filter capacitor be twice that of a half wave rectifier with filter capacitor? The conduction angle for a half wave rectifier with filter ...
14 views

Inducitve Proximity Sensor - Safety Gate Latch Codes?

If I am using an inductive proximity sensors as a safety gate latch, what codes and standards do I need to abide by? Some safety sensors I research have: - Category 3 (EN ISO 13849) - Safety ...
38 views

How to get a constant voltage output from a capacitor?

I have a piezoelectric device hooked up to a rectifier that is charging up a capacitor. I want to be able to use the energy from the piezo to charge a phone so I need to get the output voltage to be ...
25 views

STM32F3 I2C hangs on busy flag (interrupts)

I am using two STM32F303K8 Nucleos and hooked up the SDA/SCL (GPIO B PIN 6 & 7) pins to 3.3V across roughly 4.7K resistors to 3V3. When I check the voltage on the pins, both are 3V3 so it's not ...
23 views

Resistance/Voltage relation in Rheostat?

According to "How Computers Work" (Tenth Edition) by Ron White, he features a graphic of a potentiometer with three terminals on the bottom with the one on the left being for current flowing in and ...
45 views

Logarithmic amplifier with high slew rate — mutually exclusive?

Does anyone know if the basic construction of a log amp (with a diode or BJT providing feedback from output to input) is in conflict with any ability to reach high slew rates? I've been looking (...
70 views

Why am I getting a red wire for my out?

I am attempting to create an output that goes on for a certain amount of time an then goes low for a certain amount of time and my out simply won't simulate. Attached is my code, test bench, and ...
49 views

Low capacitance value capacitors in LC bandpass filter

I am going to try to build a Butterworth LC bandpass filter. However, using some online calculators result in some very low value capacitors (sub-1pF). I am thinking that the performance will not be ...
38 views

Wrong frequency response - LTSpice

So I have this simple OP-AMP circuit that is supposed to be a low-pass filter for which I made the calculations so it passes all frequencies below 1591 Hz (approx). The values of the components are in ...
68 views

Problem understanding MOSFETs

i can't understand how, in a MOSFET N, to get an expression of the voltage Vds with respect to time if Vgs > Vth (closed circuit) and if Vgs < Vth (open circuit). I saw many equations with current, ...
57 views

Is there a motor design where a rotor gradually moves into a stater?

I was wondering if there is a motor/generator design where the rotor moves gradually in and out of the stator along the axis of rotation, or the stator over the rotor, but the primary motion is rotary,...
28 views

Sequential circuit: What does state mean exactly?

I have read some posts like: What is state in a sequential circuit? about explaining what a state is in the sequential logic circuit. But the responses are pretty much the same as those ones in my ...
31 views

DC-AC converter draws large current

I am planning to build a circuit that could convert a DC voltage (i.e. 18V) to an AC voltage with frequency f=1kHz and Vpp=36V. Here is my schematic in Orcad Capture Lite. The main idea is to use an H-...
18 views

LoraWan Packet Repeater

I want to use some kind of lora-wan packet repeater or Amplifier that would amplify the lora signal, so that I can use this kind of repeater in place where there are blind spots. I know about packet ...
24 views

How do I get rid of headphone static from my old Pioneer VSX-402 stereo receiver?

I plug in my headphones, and hear static. Not just a little in the background, but A LOT of static. What is even more interesting is that the amount of static stays consistent regardless how high I ...
607 views

Circuit to “zoom in” on mV fluctuations of a DC signal?

I have a signal that is roughly 0.2V + noise fluctuations of order 0.1-2 mV. Ideally I want to amplify this signal such that the mV fluctuations become about 1V. In other words I want to amplify the ...
17 views

I have not done a lot of work with SMD LEDs and have a question about pad layout. I have done quite a bit of research and haven't found much helpful info yet. I am working with 7030 SMD leds ...
846 views

Is there a kind of relay only consumes power when switching?

The relay must stay on its state. When an electrical impulse is sent to it, it should switch its state and should maintain its status. So I am really curious about it. Is there such a thing for ...
36 views

Why a system is causal if the impulse response is zero for $t<0$?

I was reading a definition that Suppose $h(t)$ is the impulse response of any system $Y$, then the system is causal if and only if $h(t)=0$ for $\forall t<0$ I know what a causal ...
22 views

No data being displayed from ADC0804 in program using FT232RL

I'm attempting to read analogue voltage from a potentiometer by converting it into digital using ADC0804 and then passing the data onto y pc using FT232RL. As it stands the ADC0804 circuit is working ...
24 views

Hall Effect pulse multiplier circuit

I would like to use a Phase Locked Loop (PLL) to multiply a 4x signal to be an 8x signal, and modify the same 4x signal to be a 64x signal so that all three signals are available as a 5v clean low - ...
40 views

Help me interface these two nautical devices [on hold]

I'm crew on a boat which has a GPS and a tiller pilot that seem to work fine separately, but don't seem to want to talk to one-another. My captain is adamant this combination "used to work, but is not ...
19 views

MAX30003 SPI MISO line unresponsive

I am interfacing a slave MAX30003 analog front end ECG (Devolpement board, MAX30003) to a master SPBTLE-1S BLE microcontroller (Devolpement board, SPBTLE-1S). However, I am unable to see any data ...
25 views

Resistor value for Opto-coupler input

This question is in regards to the EL817 Opto-coupler(http://www.everlight.com/file/ProductFile/EL817.pdf). I'm trying to choose a suitable resistor to lower the current/resistor of the Opto's LED. ...
29 views

Transformer and Thevenin Theorem

Consider an ideal transformer connected to a real AC voltage source (with output resistance Rg). Now consider to apply the Thevenin theorem between the output terminals of the secondary circuit. I ...