All Questions

0
votes
0answers
5 views

Vdc in ripple factor

V_p(rect) is the rectified unfiltered peak voltage V_r(pp) is the peak-to-peak voltage after filtering by a capacitor Here is a picture: V_r(pp) is given by the expression: Which I have no problem ...
0
votes
0answers
3 views

DW01x vs AP9211

I plan to use DW01A + FS8205A for LiPo (or LiIon) battery protection. But when I searching alternatives I found AP9211 (internal Dual N-Channel Enhancement Mode Power MOSFET). Is anyone works both of ...
-1
votes
0answers
7 views

Custom IoT embedded device

I'm looking about an IoT device (computer board) to develop a system for production purposes, I have used Raspberry pi 3 for testing, and all things works fine. Now, for production, I need a board ...
0
votes
0answers
4 views

Altium: Error on PCB Footprint Updating

I am using Altium 14.1.5 I made a change to a footprint in a non-integrated library and then wanted to update my PCB with the new footprint and it is not updating properly. I may be doing something ...
1
vote
1answer
26 views

Cause of background buzz in my walkie talkie example?

I got a simple RF24Audio walkie talkie example working. I'm using the sketch file provided by the RF24Audio getting started example: https://github.com/nRF24/RF24Audio/blob/master/examples/...
-1
votes
1answer
53 views

How can Vo = A(V+ - V-), if V+=V-=0?

We’re considering an ideal opamp here; so does that mean that Vo is infinity ♾ * 0 (A * (V+ - V-))? Thanks!
1
vote
0answers
15 views

What are ADC channel “map,” “max,” and “amount” used for on a Microchip ATSAML21 ARM MCU?

I'm working with a Microchip ATSAML21J18B ARM microcontroller and learning how to set up an ADC input. Coming from the AVR world, things are rather more complicated. The ADC features (datasheet pg ...
0
votes
1answer
17 views

DAC offset error vs. output low voltage

I am looking at the datasheet for the MCP4725 DAC and trying to find the minimum voltage the DAC will output. In other words, when my code tells the DAC to output 0v, what will the output be? There ...
2
votes
1answer
164 views

Why does a single AND gate need 60 transistors?

Looking at the datasheet for the MC74VHC1G08, under the "features" section, it states Chip Complexity: FETs = 62. Why does this IC need 62 transistors, while an ...
1
vote
0answers
23 views

Diode behavior when reverse biased with small voltage

I'm designing a simple circuit to use a lithium-metal coin battery as a backup power supply, and I'm considering something simple like this: simulate this circuit – Schematic created using ...
1
vote
1answer
26 views

EM Vs PM Speaker

Modern Speakers have permanent magnets and are called PM speakers.Permanent magnet materials technology has improved a lot over the last 80 years .Around WW2 EM speakers were common because permanent ...
0
votes
0answers
22 views

2 pole single phase induction motor appears to have starting capacitor permanently connected (no centrifugal switch)

I am trying to repair and rewire an AC induction motor from a small compressor. From what I can tell it's a 24 slot, 2 pole single phase induction motor that has main coil and starting coil. The ...
0
votes
0answers
22 views

How to control single 12V LED with 3,3v GPIO?

Heyo! I need to control single 12V LED using Raspberry's GPIO To be more exact, I need to connect 12V LED & push button to 3.3v GPIO in order to control LED (on/off) and read button push events. ...
0
votes
2answers
34 views

Rounding up or down with Motor Overcurrent Protection

When sizing motor over-current protection, CSA 22.1 28-200 3a states that a circuit breaker can be sized up to 250% of the rated full load amperage (FLA) of the motor. E.g. 100hp, 575VAC motor ...
0
votes
1answer
40 views

Calculating Roll Pitch and Yaw from Accelerometer Data

I found these three formula to get roll pitch and yaw angles from accelerometer but these don't work when the accelerometer is in linear motion in any axis. pitch = 180 * atan (accelerationX/sqrt(...
1
vote
2answers
51 views

Any equivalent load circuit when an animal is connected to a current injector?

When the human body (chest, arm, etc) or an animal (limbs, belly, tail, etc) is connected to a circuit, I think this acts as a load. For instance, people simply model the connection between the AED (...
1
vote
3answers
55 views

What does input/output resistance/impedance mean?

This keeps coming back in every single class, and I still don't have a clear idea of what it is. I keep seeing certain statements in other explanations such as "seen by X", "looking into Y" and so on. ...
0
votes
1answer
38 views

Does alcohol set off Liquid Contact Indicators?

I have a MacBook Pro PCB that has lots of yucky, gooey and sticky grime from a spill that thankfully didn't damage the board. I would like to clean it thoroughly, but I fear turning the liquid contact ...
0
votes
1answer
15 views

Absorber effect on EM RF pattern

If I have an omnidirectional antenna and put a perfect reflector plane near it (in the near field), it will obviously change its radiation pattern in the direction opposite the reflector. ...
0
votes
0answers
22 views

Affect on C_ds in MOSFET turn off

Question boils down to whether the voltage across a capacitor can ever exceed Q/C. It relates to what happens to the drain-source capacitance when a NFET turns off. At the start of turn off V_ds and ...
0
votes
1answer
23 views

Lt-spice switch model

I have a very simple circuit and want to see the current in the inductor. But I do not know why switch is behaving like that... Actually, I supposed to get KA range current. but it gives me very ...
0
votes
1answer
38 views

Circuit MOSFET Pulldown Circuitry

Now, I have already made some progress, I have figured out what the W/L should be and made most of the circuit. Though I am not sure how I should put the MOSFETs ...
0
votes
0answers
22 views

Reduce AC voltage - op-amps circuit

I´m trying to reduce the amplitude of 160 VAC peak to peak to 2 VAC peak to peak using op amps with virtual ground. I've made this circuit but it isn't working. My offset voltage have to be equal to ...
0
votes
3answers
36 views

Resistor in series needed with LED string?

I have an adjustable 24VDC power supply. I have 1W LEDs that I was planning on stringing 7 or 8 in series to get approximately 24V across all of them together. They are rated 3.3-3.8V each. Do I need ...
0
votes
3answers
40 views

What is the importance of separate power and logic ground (ie a Vss pin) in gate driver

I have 2 different versions of a high and low side driver; IRS2186 AND IRS2186. I have attached the typical connections, taken from the data sheet (data sheet: https://www.infineon.com/dgdl/irs2186pbf....
0
votes
1answer
35 views

Passing usb data traces underneath of DCDC converter

RKZ0505D is a DCDC converter which has maximum 85kHz internal switching frequency. It is placed as large surface of it placed directly on PCB. If USB data lines pass under plastic package of DCDC ...
0
votes
0answers
18 views

Read RFID correctly with multiple cards stacked?

This may sound like a stupid question, but I'm curios about weither this works and how. Is a RFID reader (for example when paying contactless at the supermarket) able to read my credit card correctly ...
0
votes
2answers
38 views

Voltage in an RC Circuit

I made an RC curcuit on a breadboard gave it a of 25V measured the voltage across it with an oscilloscope. During my experiment it has come to my attention that the peak voltage level was getting over ...
0
votes
1answer
53 views

High PWM frequency weird shape

Using a STM32F407 if I generate a 200 Hz signal it looks like this: If I want a higher frequency, for instance 10 kHz I get this: I am using a PicoScope 2205A, resolution 8 bits at 200Ms/s, ...
0
votes
0answers
13 views

Liberate - Custom Cell Characterization

Tools and Tech: ST 65nm | LIBERATE Library Characterization Platform (x86_64) 12.1.4 (altos 121) | Cadence Virtuoso 6.1.5-64b | Calibre Interactive - PEX v2012.4_16.11 I am trying to characterize a ...
1
vote
0answers
35 views

Finding equivalent capacitance and resistance from DC circuit with combinations of R and C

In order to get the simplest RC circuit and get equivalent circuit tau: I would like to know if it is possible to reduce the next circuit to another one with an equivalent C and equivalent R? How ...
-3
votes
0answers
24 views

Phase shift between the winding of a three winding transformer [on hold]

What is the phase shift of the output voltage of a three phase three winding transformer connected as follows: Primary: Delta1. Secondary: Delta11. Tertiary:Wye. Is there a 15 degrees phase shift ...
0
votes
1answer
34 views

Use lithium ion car jumpstarter to charge netbook?

I have a Gooloo car jump starter pack. https://www.amazon.ca/gp/product/B06X9R8QSY Can I use it to charge a small Gateway Nav50 netbook? What kind of adapter would I need? I suppose I could use ...
-1
votes
0answers
27 views

Wiring Connection from RS-485 to RJ-45 Port

I want to connect/wire from RS-485 A and B (only 2 pin) to RJ-45 port, anyone has the schematic diagram that show hows the wiring?
0
votes
1answer
41 views

Some questions on inductance measurement of a solenoid

I'm planning to measure the inductance L of roughly this solenoid-valve roughly by using the following setup: I measured the resistance of the solenoid RL as 55 Ohm. L is unknown. I think I can ...
0
votes
2answers
58 views

What happens when switch is open

In a simple circuit, composed only of a lamp, a generator and a switch that connects the generator to the lamp. What happens with electric current when the switch is open? Electrons turn around? They ...
0
votes
0answers
54 views

Voltage regulator not outputing desired voltage and extremely hot

Now that I have understood how to connect my transformer to output 18V, I now have a huge problem with heat and wrong output voltage. I also smells and you can feel the heat. Here is my design ...
1
vote
1answer
27 views

USB 3.1 Gen 1 Transfer Speed Through Hub

If I have a USB Host Controller that supports USB 3.1 Gen 1 plugged into a hub, and 2 storage devices connected to the downstream ports, if I transfer data from one storage device to the other through ...
0
votes
0answers
23 views

Nand Flash Memory Chips [on hold]

How would I program a Nand Flash Memory chips to read and write? I have an FPGA, a Nand flash memory, a socket, and some cables. I just want to know the procedures or step by step by doing this! How ...
0
votes
0answers
28 views

Microcontroller resets with motor driver (L293D)

I am making a simple robot with 2 BO motors driven by L293D on ATmega328P (took out from Arduino Uno). The robot when tested on Uno works fine. But when I put it on the board that I have designed (as ...
-1
votes
1answer
84 views

Could someone explain what is clock data recovery?

I have read that clock data recovery is essential for decoding signals, for instance decoding output of rotary encoders But I don't know how it helps to decode signals. Any hint or reference would ...
-7
votes
0answers
26 views
0
votes
1answer
16 views

Definition of Field Wiring Terminals as in UL 499

I'm wondering if anyone can tell me where I can find the definition for "field wiring terminals" as referenced in UL 499 "Standard for Safety Electric Heating Appliances" table 27.1 "Minimum ...
0
votes
1answer
40 views

Using Character Match functionality in a STM32F7 chip

I'm trying to implement a UART receiver that works by finding a '\0' in the datastream, OR when it receives 256 characters at which point the data should be processed by an interrupt. The point is to ...
1
vote
2answers
86 views

How to take resistance reading when value is effected by measurement?

Context I am trying to measure the wiper resistance of a potentiometer. This is performed by leaving the potentiometer wiper in one position, and measuring from each terminal to the wiper (\$R_1\$ ...
5
votes
2answers
617 views

What really causes series inductance of capacitors?

Doing some research in selecting capacitors for high frequency applications, concept of equivalent series inductance comes up a lot. Apparently all capacitors have this parasitic inductance which ...
0
votes
0answers
20 views

BLDC hoverboard motor with no specifications

I have this kind of motor but I can not find any electrical specifications about it. All I know is that is a 36V,250W BLDC motor. How can I determine the number of poles, the coil resistance/...
0
votes
0answers
11 views

ili9341 using 3 wire with stm32f030

I am working with ili9341 TFT Display with STM32F0 MCU. And TFT display was connected with 3 configuration. I am confused between sending the "command" and "data" using spi communication. So can ...
0
votes
1answer
80 views

What causes the series resistance in capacitors?

Especially in high frequency circuits there often seems to be the problem of ESR of capacitors. ESR apparently is a characteristic of non-ideal capacitors, and is essentially a resistance appearing in ...
0
votes
1answer
36 views

DC Motor Controller using only one button?

I have been trying to create a DC motor controller that can do numerous actions with just the use of one button. Basically when I click it has to go on way, when I click again it has to stop, and ...

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