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3 views

simpelst way of i2s/pdm microphone with usb

i have developed, a mems i2s microphone with a USB-C, that uses the PSOC4 chip from cypress. now we want to scale this product but the problem is the delivery time of the PSOC is horible, this is a ...
0
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0answers
5 views

What is the voltage output of an Apple 85W MagSafe 2 model A1424 without a load?

What is the voltage output of an Apple 85W MagSafe 2 model A1424 without a load? Thank you in advance
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0answers
2 views

LinkSwitch-XT2 (LNK3696) with opto feedback

What's a proper circuit if I want to use a LinkSwitch-XT2 device (from Power Integrations) with an opto coupler in the feedback loop? This is the typical application circuit of LinkSwitch-XT2 devices....
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0answers
12 views

Parallel RLC Circuit: how to write differential equation?

Please consider the following circuit: At t>0 this circuit will be transformed to source-free parallel RLC-circuit, where capacitor voltage is Vc(0+) = 0 V and inductor current is Il(0+) = 4. Now is ...
1
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1answer
26 views

Designing a 555 led blinker

Found a nice guide on how to make a led turning signal for bikes based the 555 timer which contained this schematic: But no matter how I do it, I cannot make it work.The leds won't blink.... What's ...
0
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0answers
20 views

How to calculate current in a symmetric circuit diagram

I am relatively new to circuit diagram and i am trying to find how out how i can calculate Io shown in the above diagram. From my understanding, this looks like a symmetric circuit diagram, however i ...
0
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0answers
21 views

Replacing smoothing capacitors in vintage guitar amplifier without datasheet

I'm in the process of servicing my Carlsbro stingray super combo amp and whilst disassembling I noticed that one of large caps (I assume smoothing) has started bulging and leaking. Ive tried ...
0
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2answers
30 views

Is there a reason why lower voltage batteries are preferred for high AH?

I was looking at these batteries and considering whether to use a 12V battery or multiple 2V batteries for backup power. In any case, I came across this battery by Exide Tech - GNB Flooded Classic H1T ...
0
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0answers
18 views

Why is my Voltmeter/Ammeter not reading amps correctly?

I am having problems correctly setting up my volt/ammeters. I am attempting to use them to monitor a boost converter I recently purchased. I would like to have one set up on the input of the boost ...
0
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0answers
6 views

Problem with driving TCD132dg CCD sensor

I'm trying to drive TCD132dg, which is a ccd sensor, by FPGA Spartan6. All clocks and controlling signals are correctly produced by the FPGA according to datasheet whithout delay, but the output doesn'...
-1
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0answers
15 views

HIN232(max232) IC burnt frequently

I made a circuit using a MAX232 IC. I used that for 2-3 week and it was working well. Suddenly yesterday I found that serial transmitter and receiver is not working. I tried to debug circuit and I saw ...
0
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3answers
22 views

Capacitor Selection for high voltage

I have a circuit which has about 10 kilovolts input and I want to store that voltage on a capacitor. I calculated and drew the circuit but I am now using an 18 nano farad capacitor at the end. I ...
0
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0answers
9 views

Mesh equations currents

Hello guys. I am in freshman year of electrical engineering. And finding it difficult with circuit analysis. Please help me to write mesh equations, current mesh and current through each source.
0
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1answer
13 views

Can servos have a true neutral gear?

I am developing a mechanical arm that can be pitched remotely at a certain angle using a high-torque servo motor. The servo needs to keep the arm at a precise position for any give amount of time and, ...
0
votes
1answer
16 views

Controlling a 19x19 input matrix

I'm designing a go board that can detect where pieces are placed through a raspberry pi for the purpose of game recording. I'm planning to put magnates on the bottom of pieces and do the detection ...
0
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2answers
32 views

Motor choice for quietest (mechanical and electrical) operation

We are investigating a motor for a laboratory test dynamometer. What is the best type of motor for the following specifications. One of the key requirements is a minimum of mechanical and electrical ...
0
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0answers
20 views

Design Bootstrap Follower

I got confused in the emitter follower circuit with tracking feedback (bootstrap). The mechanism of operation is understandable, but how do I choose the resistor values ​​correctly and optimally? For ...
0
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0answers
11 views

High Side Driver Array Against ULN2804 For Motor loads Such As UDN2981, TD62783, TPIC6B595

Building a circuit to drive a few DC motors with UNO, 74HC595 and ULN2804. I had no issues with coding, connections and timings. Then I started searching for high side driver arrays to control ...
0
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1answer
22 views

Unidirectional vs Bidirectional TVS diode for ESD protection UART bus

On my board comes a UART line with a voltage of 3.3V. To safely communicate with the controller on 5V, I use a level offset based on BSS138 transistors. My goal is reliable ESD protection of the UART ...
2
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0answers
29 views

Convert 3V unbalanced microphone to 48V phantom balanced

I have the following circuit in an existing product, which has a microphone, power switch, LED indicator, and is powered by 2 AA batteries: simulate this circuit – Schematic created using ...
0
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0answers
30 views

Ferrite Core Manufacturing Process

My question is about Ferrite Core. Is anyone help me or share with me how ferrite core is manufactured?
1
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1answer
25 views

Understanding pci address in lspci/dmesg

When looking for the pci devices on the host machine, I have seen something like this in lspci: ...
0
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1answer
46 views

Connecting Ne555 chip's 7 discharge pin directly to supply

I'm building a adjustable frequently generator with ne555 timer . But I don't want duty cycle to change with frequency so Can I connect the 7 discharge pin directly to supply and add a potentiometer ...
1
vote
0answers
18 views

AXI4-Stream TVALID stuck low between VDMA and video output block

I'm trying to buffer a single frame of video using a VDMA block on a Trenz TE0712 board (artix-7 based development board), based on a few examples (specifically Numato's framebuffer example and Xilinx'...
0
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0answers
45 views

UART read consistently missing half of the transmitted bytes

I have setup a simple UART test on my SAML21 and believe I must be misusing the library due to the behavior I'm seeing ...
0
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2answers
23 views

RS422 Receiver Not Reporting Errors When Too Few Stop Bits

I am interfacing with a device (the transmitter) which configures its serial settings to 8 data bits, no parity, 1 stop bit at a baud rate of 115200. These are known values and fixed values I can't ...
0
votes
1answer
35 views

ESC control with Raspberry Pi

I'm trying to control some ESC and brushless motors using a raspberry pi. I used the pigpio library to control them using servo pulses. But it seems that my motors wont increase rpm after a limit ...
0
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2answers
60 views

Component Identification 220V

A component of a board from an appliance has failed and I would like your help identifying it, in order to replace it. Below is a picture from the board, the arrow points to the failed component:
2
votes
0answers
29 views

Spurious microwave emissions perhaps coming from conducting TRIAC controlling AC power?

I have a TRIAC switch on an 240VAC single phase AC line. There is voltage on the gate as specified, there is a small dead band near zero. I.e. it is conducting as expected. However, I'm picking up ...
0
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0answers
23 views

How to ontrol a 12v dc water valve with battery powered Arduino?

I just want to open/close a valve when the soil moisture sensor reports a pre-determined moisture level, using an Arduino. The main issue I'm facing is that most valves operate at 12/24 VDC and I'm ...
0
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0answers
54 views

Three phase motor too high no-load current

I got an old three phase motor (20+ years) which consumes more current than it should. The motor specs are: ...
0
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2answers
86 views

Why is this circuit causing my breaker to trip?

I'm an electronics hobbyist and I decided to make my own electric heater/kiln thingy. It works fine for a couple of minutes, but then the breaker trips. This is my first project involving AC, so I'm a ...
5
votes
2answers
86 views

Discrete component FM radio receiver circuit - explanation needed

I have built an FM radio receiver from a kit. I'm very happy with the results! It is the Sinclair Micro FM. My goal is to learn about discrete electronics (NO IC's.) The radio works great, but I ...
0
votes
1answer
36 views

How to create a buck-boost converter with a low-voltage cutoff

Hello i would i am in need of a constant voltage regulator to power my motors, as voltage will affect the motors rpm. Although i could compensate via software, i would like to add a hardware ...
-1
votes
1answer
56 views

LED REACT TO MUSIC [on hold]

I want to ask if anyone can tell me what transistor and resistor I need to use for 5v led RGB lights ( i need them in green or blue only). Here is a link to the video I'm taking info from: https://m....
-6
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0answers
55 views

cabn;t contribute? Really? [migrated]

I was going to document my findings on Weller WTCPN repairs, part by part, but apparently i need do something more first. Kinda limiting ad chases away contributors, IMO. Unclear why you do this. ...
0
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3answers
81 views

So why do battery chargers need two prongs? Why not just one?

Electricity flows from area of highest electric potential to lowest, I get that. What I don't get is why any battery charger would use two prongs on an outlet (or a few other items of similar purpose)....
0
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1answer
39 views

Switch that change its state with a signal of some seconds

I'm making an IoT project for a friend, but I need some tips: I want to use an old mouse sensor and convert it to a movement sensor (just for a door) and if it's activated, a second device (an esp8266)...
1
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0answers
47 views

Understanding Self Power Supply

I took the circuit below from an App Note from Texas Instruments, and I decided to study it. My questions are about the comparators U6A, U6B. About U6A: The inverting input is set to 0.7 V because ...
0
votes
1answer
25 views

PoE Design for Camera Interface Isolation Question

We are designing a PoE design to power our camera. The block diagram below is the basic design we are planning to implement. I want to get some advice to make sure we will not be damaging our camera ...
0
votes
1answer
28 views

Decoupling capactor for DC voltmeter

I have a DC measuring digital voltmeter. The power for the voltmeter is coming out of a charging rectifier. The frequency out of the charging rectifier is anywhere between 20 and 60Hz. Operating ...
0
votes
2answers
68 views

Why is current flowing mostly through the base (NPN transistor)

I am currently working to install an NPN photoelectric sensor (retro-reflective dark on: https://www.automationdirect.com/adc/shopping/catalog/sensors_-z-_encoders/photoelectric_sensors/18mm_round_-...
0
votes
3answers
44 views

current drawn by led increase with more leds you put in parallel??against V=IR?

current drawn by led increase with more leds you put which i saw in a video about thyristor ,but more leds means more resistance which means lesser current which is not true as per the video(https://...
0
votes
1answer
53 views

Simplest circuit to reliably produce two voltage peaks, then nothing

I'm trying to make a circuit with basic components and simple IC's that starts low, produces two pulses of high returning to low in between, in ideally a square wave though anything that doesn't ...
2
votes
2answers
81 views

How can you damage DMM if you haven't discharged a capacitor?

Hi, I measured capacitance on some capacitors using my UNI-T 139S True RMS Multimeter without discharging them first. To be clear, I don't even know if they were charged because they are mounted on ...
-1
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3answers
99 views

Zener Diode vs LM78XX

To get, say 5VDC, from the AC mains, after stepping down the high AC voltage using a transformer, we have to rectify it and regulate the output DC voltage. As I have seen, there seems to be two ...
7
votes
2answers
471 views

What is wrong about this application of Kirchhoffs Current Law?

At a recent exam I had this very simple problem concerning Kirchhoffs Laws: I am concerned with problem c Now my understanding of this is: I can combine both nodes, and since all currents in the ...
0
votes
1answer
26 views

Designing a circuit for TRRS Socket

I'm building an electronic musical instrument which I would like it to have a 3.5mm audio output socket, so it would work with any "regular" headphones, like a cellphone does. For a long time, I've ...
-5
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0answers
78 views

Future of Electronics [on hold]

Actually I am studying electronic engineering and I have to make a choice of specialization. Until now what I have learnt about circuits can be divided in two cathegories: on one hand everything ...
0
votes
1answer
37 views

Identifying motor

What kind of motor is this and what is the signal used to rotate it? It has 4 coils and each coil has a pin coming out of it except for one coil (number 4) it's only connected to the coils next to it. ...

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