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Seeking low-cost level shift solution

I need to interface two high-voltage MOSFETs to a PIC microcontroller. This normally easily done simply using a MOSFET or bipolar transistor as an inverter. However, my added constraint is that the ...
0
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0answers
3 views

What is causing that characteristic chirping noise in switching power supplies?

every now and then a switching power supply like the ones from mobile phones, laptops, etc. is making this very characteristic chirping noise. I wondered what component in there is causing this noise, ...
0
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0answers
10 views

Optocoupler always on

I am trying to experiment with optocouplers, and eventually use it to connect my Raspberry to a relay I have done this circuit: using a Toshiba TLP523: http://www.farnell.com/datasheets/24716.pdf?_ga=...
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1answer
10 views

USB data and Power cable with Switch to power Arduino. Is it a safe design?

I have some projects with Arduino and a separate battery power source and I'm tired of plugging and un-plugging my usb cable when to program the arduino using my laptop USB. Sometimes it even broke ...
0
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0answers
8 views

What would happen if I spliced a 240v 2.71a line from a generator to the output of a computer UPS?

I need a way to switch between a generator and a UPS when the power goes out to keep my internet connection and a small 65w server running. I cant just pull the UPS outta the wall and connect the ...
0
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0answers
19 views

Repair MRAM that's been exposed to a magnetic field

Is there any way to repair MRAM that has been exposed to a magnetic field? I've got a bit stuck (3rd bit) on my MRAM. Probably due to exposure to a magnetic field. Is there any way to fix this short ...
0
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1answer
19 views

RC Filter vs Bypass Capacitor to Ground

I am confused with how to implement a method of filtering out the impedance from the ground path of an IC. I'm thinking that I should use an RC filter circuit in order to smooth out the current and ...
0
votes
3answers
58 views

What is the box at the end of a USB cable?

Not the cylinder that hangs onto the cable itself; the actual box at the end that you grab onto in order to pull it out or push it in. They often have the USB logo on them. Is it some sort of ...
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0answers
11 views

Cascading Isolated Power Supply

I want to implement a few chips for battery management and due to the ADCs of each cell working at bigger voltages each, and each chip(I have to cascade thre ICs LTC6803-4) with a maximum voltage ...
0
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1answer
25 views

Digital High with 3.3V and 1K resistor

I was wondering if it's necessary to add a 1KOhm resistor on a digital input that listens to HIGH signals (3.3V) or I can just feed the 3.3V to it without any protection. I'm making a circuit to ...
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0answers
31 views

Generate spikes on RS485 bus

I was thinking to build some test equipment for a RS485 bus, but Would like to get some suggestions on how I can introduce bursts of spikes in a "safe" way without damaging the connected ...
1
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2answers
28 views

3.5VDC Lights on 3.2VDC Cell and charges cell voltage too Fast

I had a light string that was powered by a 120 VAC to 3.5VDC 800 mA transformer. I hooked it to a single 3.2VDC Cell. It burns really bright at first, then dims, then goes out after 2 hours. The Cell ...
0
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0answers
17 views

Solution for a 5V battery on PCB (with USB charging)

I don't know with which keywords I can start my research efficiently so I'm coming to you. I'd like to add a part on my PCB where I can store a 5V battery (on the PCB) with possibility of charging via ...
0
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0answers
36 views

How can I boost the voltage of a headphone output signal to use with “aux in” on car radio?

I'm frustrated by the fact that I always have to crank to volume to max in order to utilize "aux in" ports on things like my car stereo when sourced from a smart phone or PC. It seems that ...
0
votes
1answer
37 views

Saftey regulations of multiple 1mW lasers

AFAIK devices containing exposed 5mW lasers are illegal without a license, but those containing 1mW lasers are. But how about a device with ten 1mW lasers? Is it still a safe and legal device? The ...
0
votes
1answer
37 views

Can a thyristor regain its forward/reverse blocking capability if the current through it is “instantly” brought to zero?

I am imagining a situation where we have several series-connected thyristors, say 10, each that can block a voltage of 100V. So, the ten series-connected thyristors together can block a total voltage ...
1
vote
1answer
28 views

How can I reattach tiny wires to a tiny circuit board? [closed]

These power supply wires broke off due to my carelessness. How can I reattach them without soldering?
0
votes
1answer
45 views

Why did the designer of this flyback circuit choose to set the oscillation frequency as high as possible with the smallest resistor tolerated?

This circuit uses a current mode controller with an oscillation frequency response of: In the circuit, the designer chose to use a 10nF cap, with a 680 ohm timing resistor, which according to the ...
0
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0answers
29 views

explanation of DC ceiling fan motor and hum and noise [duplicate]

I asked a while back why does a ~$150 120vac electric ceiling fan, above my bed at home, hum and agitate me. Didn't come to a 100% solid reason but I believe it's due to that motor being a brushless ...
0
votes
1answer
30 views

TF-Mini S lidar not sending any serial data

I have a TF-Mini S Lidar. I have hooked it up to my arduino like so: (Above image from learn.sparkfun.com) And have uploaded this code to the arduino board: ...
3
votes
1answer
52 views

What prevents the lead attached to a semiconductor from forming Shottky junction

What prevents lead attached to a piece of semiconductor (for example in BJTs and FETs) from forming a Shottky junction?
0
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3answers
92 views

What's the name of this electrical connector?

What's the name of this electrical connector?
1
vote
2answers
35 views

Identify molex connector

Anyone know what kind of connector is this?The female connector size is around 18x7 millimeters
0
votes
1answer
37 views

Powering the blue pill board from laptop and using another power supply at the same time, will this cause problems?

The components: a laptop, a blue pill board, a +5V power supply(taken from old PC). I have a blue pill board(stm32f103c8t6 mcu). Schematic here. I connect my laptop to the blue pill board via SWD ...
-1
votes
1answer
45 views

Use capacitor as keep-alive for alarm clock [closed]

I would like to integrate a capacitor onto the power supply of an alarm clock to prevent the flashing "12:00". Which would be the best way to implement?
2
votes
1answer
38 views

Need Help Creating SATA Power Cable for Lenovo C540 AiO

I need expert help. I have an old Lenovo C540 AiO desktop that I am trying to salvage. This model is prone to a failure in the SATA power cable, at the HDD connector end. I have found video guides on ...
0
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3answers
67 views

How can i make a frequency dependent switch?

Is it possible to make a circuit/switch that turns a relay ON whenever there is a certain RF frequency applied and keeps it OFF for all other frequencies. The RF signal should not carry any ...
0
votes
1answer
50 views

How can i protect N-MOSFET from failing

i have made simple inverter circuit with z44 MOSFET but circuit work for minutes and the primary coil start heating then shorting finally damage the MOSFETF, it is my 6th time facing this issue. i ...
0
votes
1answer
45 views

Ferrite core StepUP Transformer Design

So, I want to make a High-Frequency Ferrite transformer that can convert my 150-volt peak Square wave into 100000 Volt Peak. I am using UUR6440 Ferrite Core. Material is CF139 https://www....
0
votes
1answer
42 views

FET electrode convention?

Are there any conventions that allow one to tell which electrode is source and which one is drain?
-2
votes
0answers
27 views

2 Phase servo motor operation

Can somebody explain to me how 2 phase servo motors move loads? Have researched online but all explanations are very brief, a main winding connected to an AC source, a control winding with variable AC ...
0
votes
1answer
23 views

How to compute Rth for this circuit using OrCAD PSpice

Take a look at this circuit The question asks to find Rth and Vth between a-b terminals. Hand calculation yields Rth=3.857 and Vth=4V. With OrCAD, the result is shown below using Bias Point ...
1
vote
1answer
37 views

Linear regulator with tab at ground

I am searching for a linear regulator with tab connected to GND instead of Vout because it would be easier for thermal management. Unfortunately, all linear regulators seem to have their tab connected ...
0
votes
1answer
43 views

Do I need to suppress ringing in a flyback converter?

I am about to design a flyback converter. As all flybacks with no extra measures it has some ringing. You can see that ringing in this example from -1µs to 4µs: This ringing can be surpressed by a ...
1
vote
0answers
44 views

Schmitt trigger output waveform coming as sinewave

I am new to Proteus. I tried simulating an easy circuit which was a Schmitt trigger using an op-amp. After simulation, the output waveform was an sinewave instead of rectangular wave. Any idea where I ...
-1
votes
0answers
36 views

Disadvantage of an AC tachogenerator

I was researching on AC tachogenerators and how they are used for velocity feedback to reduce load oscillation. However I came across a disadvantage of using it, it always will have an output even ...
0
votes
2answers
57 views

Logic buffer design

Logic buffer is usually depicted like this: But can this work equally well? And if it's not the case, why not?
1
vote
1answer
24 views

MPU9250 IMU wearable design considerations and device address problem

I need to use 12-16 mpu9250 IMU for wearable design. Each IMU will be placed different places on the body. Therefore, I want to read data from each device by using I2C interface. However, problem is ...
0
votes
1answer
31 views

Not matching 50 ohm impedance

For my RF circuit (868MHz), I need 50-ohm impedance. When I calculate the impedance as PCB manufacturer layer stack-up, the impedance would be 66 ohms. How does this affect my RF circuit performance? ...
0
votes
2answers
53 views

Confusion in current calculation

I'm confused about two different approaches for current calculation through a 5 ohm resistor. The 5 ohm resistor is in parallel with a voltage source so the current through it should be 2 amperes. ...
0
votes
0answers
22 views

Low Power Toroidal Conductivity Sensor Inconsistent Values

I have been trying to build a low power toroidal liquid conductivity sensor using the principle given in this image. This link has more information about the principle behind the sensor. What I have ...
0
votes
1answer
29 views

PCB designing of GSM module

I want to design PCB of a GSM module. Inside a GSM module there is a place to put a (mobile cellular ) SIM card. And then this GSM module can send SMS text messages to different phone numbers. ...
0
votes
1answer
26 views

E/I inductive position transducer sensing device operation

so I have been doing some research on AC servo position flight control surface systems an was trying to find the component used to set the pilot's input command. Found out that a E/I inductive ...
-3
votes
0answers
28 views

Ethernet switch- Communication

I have a small doubt on using Ethernet switch. Query: Below is my setup will the communication happens between Board1 & Board2 through ethernet switch.
-1
votes
0answers
26 views

Trying to power up Amazon Echo in car

So I want to connect my car with Amazon echo show. Currently I connected it to the 12 v power output( cigarette lighter ), however when the car is started the power is interrupted ( while starting the ...
1
vote
1answer
63 views

Opto-isolation amplifier output is too off

(As a follow-up to an earlier question answered by the community - thanks!) So I've got the test circuit setup using the HCPL 7520 (datasheet) now and planning to use an Arduino Uno to measure the ...
0
votes
1answer
34 views

Differential gain of op amp

So I was reading the chapter on Op Amps in Microelectronic circuits by Sedra, Smith, the topic on Differential Amplifiers to be exact. Here's the amplifier: https://i.stack.imgur.com/3qWzi.png To get ...
0
votes
1answer
33 views

Non-inverting unity gain buffer appears to be inverting

I have constructed a circuit which uses two non-inverting unity gain buffers on one chip as stage seperation. I'm using a TL072CP chip with dual op amps on it and have followed the datasheet design ...
0
votes
1answer
38 views

4 layer buck converter layout

What is the standard layout for a 4 layer PCB that everyone follows for a buck converter or similar? I was planning to go like this: Signal Vcc GND Signal Since inductors and FETS are noisiest of ...
1
vote
3answers
73 views

How does the Colpitts oscillator provide positive feedback?

This is a Colpitts oscillator in a common-emitter configuration: For oscillation to occur, there must be a positive feedback. But I'm confused how can this oscillator provide a 360° degree turn for ...

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