All Questions

0
votes
3answers
17 views

what is the triangle component in electronics?

From the following image we can see 3 triangle symbols: looking to the triangle to the right i suppose it is a voltage buffer, but the ones at the left have 2 inputs. What are they?
0
votes
1answer
16 views

Band pass filter bandwidth problem

I am trying to design a band pass filter that allows frequencies between 16,384Hz and 32,768Hz. Firstly I tried to make it using a passive RC band pass filter: Using the formula fc = 1/2πRC, the ...
0
votes
1answer
34 views

Does current drive voltage in a transistor?

I have this circuit, but I want to know how much voltage will be dropped between base and emitter of the transistor, and how much over the 1k resistor on the left. Since a transistor does not have a ...
0
votes
1answer
33 views

What's the purpose of the inductor in this microphone biasing schematic?

I'm just wondering what's the purpose of the inductor in this microphone biasing schematic? Could it be that I have very low input signal from the microphone because of missing L1? Bias generator ...
0
votes
0answers
11 views

Does my PWM led circuit controlled with NodeMCU and Mosfet work properly. What should I do to improve it? How to calculate for each components?

If I understand it right, when there's is signal from ESP, the PNP and NPN be ON, and Vgs=0. If they're OFF Vgs=+12V and the LED will shine. R=1K is to limit the Ib of NPN, and R=10K is the resistor ...
-1
votes
1answer
57 views

Will love to understand how the circuit works based on this schematics

Just a pure understanding of the workability of this circuit.
0
votes
0answers
13 views

Connecting a standalone temperature probe to a Raspberry Pi

I have a standalone temperature probe. I have also a raspberry pi. I would like to get the data from the temperature probe to the pi. I have thought about cutting the probe and using direct but ...
0
votes
1answer
25 views

Building Led light which work on 230V supply

I have a couple of 9W LED bulbs(1) at home with blown drivers. I got some replacement boards(3) with driver circuit and LEDs on the board itself. Now that the old LEDs(2) along with the aluminum PCBs ...
0
votes
2answers
18 views

Grounding balanced secondary isolation transformer for EMI suppression

simulate this circuit – Schematic created using CircuitLab Which is the best secondary connection to clean the main line power from EMI, line noise and HF harmonics by using an isolation 1:1 ...
0
votes
0answers
7 views

Can torque angle of motor be positive?

For any motor text say that, the rotor field follows the stator field with a certain torque angle. And in case of generator, the stator field follows the rotor field with a negative load angle. The ...
0
votes
2answers
17 views

Adding a sound adjustable Potentiometer for LM4910

Guys iam attaching an LM4910 headphone audio amplifier circuit with this thread, Can anyone help me where i need to place a potentiometer to control the sound output. Also is the shutdown pin needs to ...
0
votes
0answers
14 views

Unstable speed with A4964 BLDC controller

I am using an Allegro A4964 for controlling a BLDC micromotor. I have tuned the PID and all available parameters according to the documents available from Allegro. Problem: In the control modes I ...
-1
votes
1answer
30 views

40kHz Ultrasonic transducer - datasheet gives capacitive load at 1kHz what is it at 40kHz?

A hopefully simple question, the datasheet for a 25kHz Ultrasonic transducer gives the capacitance load at 1kHz what is it at 25kHz? I've been calculating the current using I = fCVpp where f is ...
-1
votes
3answers
53 views

Motorbike turn-signal blinker starts OFF, i want it start ON

I've bought a cheap blinker that claims to be good for LED bulbs (so the frequency is indipendent from the load). It is true, but it has a flaw: the lamps go ON only after about a half second from ...
-4
votes
1answer
69 views

The Art of Electronics Third [on hold]

Is this a good book to learn electronics with bad maths skills ? e.g algebra I find hard to solve and rearrange equations
-1
votes
0answers
19 views

Sinotimer progamable timer relay

Unfortunately it burnt due to power short circuit or another reason. After open the circuit I have found two problems: The resistor acting as a fuse is burned which was wire wound fuse resistor. The ...
-2
votes
1answer
33 views

Tool for designing electrodes for PCB Mill Machine [on hold]

I need to draw really simple layout, where i have only 2 electrodes and traces for them. Electrodes are 2x2 cm squares and i need traces to be thin like 0.15mm. I will need to create gcode from this ...
5
votes
3answers
96 views

resolution bandwidth

I have the following trivial question: I have acquired a noise spectrum with a resolution bandwidth of 124 Hz. I would like to convert it to V/sqrt (Hz). Shall I simply multiply or divide the signal ...
0
votes
0answers
24 views

“Solder PCB High Voltage connection” or “Flying Lead HV connection” reed relay model for high voltage PCB design?

I'm searching for the HV reed relay solution for channels multiplexing board design: V < 6KV, I < 10mA. 8 relays that connect 8 input pins to V or GND (given for an external supply device). ...
0
votes
2answers
70 views

What is the triangle components in this diagram?

I am reading through datasheet of a voltage translator for I2C (FXMA2102) and I cannot understand the triangle components in the block diagram: Are they diodes to make current flow in one direction? ...
1
vote
4answers
74 views

Is this way of sizing the series resistor for Zener regulator correct?

This is a completely made up imaginary question to ask the question easier. Let's say I have a 0.1W 5V Zener diode. And I want to use this to regulate from 9V to a 10k load. I draw this as in the ...
0
votes
1answer
36 views

Long Distance High Speed Wireless Data Transfer

What kind of device can I use to transmit data at a rate of 1MB/min up to a distance of 100 miles? If that's not possible, what's the farthest distance to which I can transmit the data.
0
votes
0answers
62 views

Need help getting started on my first project - Flexible PCB circuit routing

I am new to electrical engineering so I am trying to explain my project in simple words - please excuse wrong terms, etc. :) The software part is less an issue for me because I know how to write code ...
1
vote
1answer
75 views

What is the role of the rightmost transitor in this circuit?

I extracted the following circuit from an schematic. It is part of power section. The switch on the +2V line is actually a GPIO from a microcontroller which turns to +2V when powering on the device. ...
1
vote
0answers
13 views

Unitary property of scattering matrix

From s-parameter lossless network definition , The sum of the incident powers at all ports is equal to the sum of the reflected powers at all ports. But how do we derive the above unitary property ...
-2
votes
0answers
40 views

What's best for separating signal from noise, lock-in amplifier or averaging with digital oscilloscope?

Or isn't there a best one but maybe they are good in different scenarios, say that the noise is 10 times bigger than underlying signal, which one is to be preferred? Similarly, if the noise is say ...
0
votes
0answers
26 views

Laptop battery SMBus broadcasting

I connected a laptop battery connector to a micro-controller through SMBus. I can read information from battery such as state of charge. I listen to the battery broadcasting charging current and ...
0
votes
0answers
13 views

Command from Openocd to deactive Target

Can someone tell me if there is a command from OpenOcd that we can deactivate/stop the Target for a while? I am flashing 4 devices in a daisy-chain with Jtag and OpenOcd. After devices were flashed, ...
1
vote
0answers
14 views

Can I use the transfer function of a servo DC motor as a close approximation to the transfer function of a stepper motor?

I have been trying (just spent many hours on this) to find/calculate/derive the transfer function of a hybrid stepper motor. I don't need an exact transfer function (the electrical and mechanical ...
0
votes
1answer
22 views

Why double synchronizer alone is not enough for multi byte transfer between two clock domains?

When one bit information is transferred between two different clock domains, we use 2 Flip-flops or double synchronizers. But when we transfer multi bit signals across two different clock domains, why ...
0
votes
0answers
13 views

Flash and debug of multiple STM32 in JTAG with J-LINK

I have a board where 3 STM32 are connected to a JTAG port. The 3 STM32 are daisy chained. I am using a JLINK EDU Mini with Atollic TrueStudio IDE. One STM32F746 is a master for the two slaves ...
3
votes
1answer
492 views

IR receiver - what part it is?

Bought an IR repeater with the simple schematic: The question is, what is this receiver? It looks almost like 4838, has the same pinout, but it outputs encoded signal and I cannot find what is it. ...
0
votes
1answer
50 views

Styrofoam cooler/chest ok for electronics project?

I'm building a DIY power supply using 6 server power supplies. I've been looking for a case/enclosure to hold them and the necessary wiring and came across a styrofoam cooler that's the perfect size ...
-3
votes
0answers
24 views

Mobile gpu for 2x30megapixel~200megapixel 30 fps image processing? [on hold]

I would like to build some hardware to toy with my vslam/odometry algorithm. But I cant decide which gpu should I pick. Anyone may give me a pointer or some kind of good reference? Thanks.
0
votes
1answer
36 views

Garage sensor - in a need of a distance/obstacle detection relay to work for 2-3 m distance

I am building a distance/obstacle detection sensor to detect if it is safe to close garage door already (i.e. car is fully in and is not blocking it, still preserving some space to walk in the rear). ...
-1
votes
1answer
35 views

Simple battery backup

I am experiencing sudden outage in my area from few seconds to a hour or so. I am currently using this circuit. Turning on and off every time for a blackout is just annoying. I just want to cut off ...
1
vote
2answers
34 views

SVPWM: Does setting modulation index to 0 still consumes power?

I've implemeneted a 3rd harmonic injection SVPWM (Space Vector PWM) scheme and it performs quite well. One peculiarity i have noticed was, when i set the modulation index to 0, the motor stops as ...
0
votes
0answers
24 views

vintage amp component popping and crackling [on hold]

Hi i have a vintage pioneer sx-650 recevier when I plug it in I hear a light poping / white noise sound coming from around the transformer area not Shure if it is the electrlitic compassitors or if I'...
1
vote
3answers
86 views

Finding short-circuit across 3.3V power rail and ground rail on PCB

I have a short-circuit between my 3.3V and ground power rail on my assembled PCB. How do I find where the short is? Should I start by removing components one-by-one from the board?
1
vote
1answer
113 views

What this component is?

I'm reverse engineering a pcb but i'm stuck at one component which i cant find out what it is.i thought it is a diode because of the marking on top of it but when i test it with multimeter it behaves ...
0
votes
1answer
57 views

Limit 540 mA CC driver to 300 mA?

I have five 10 W, 34 - 38 V, 300 mA LED COBs I'm wanting to run these in series but to reach the voltage and watt range in the driver, I can only find a 540 mA constant current dimmable driver. I want ...
0
votes
2answers
29 views

Finding the settling time of an oscillatory response

I was reading my book on circuit analysis on chapter about RLC response and became curious about how to get an approximate value for the settling time of the response. Particularly this response ...
0
votes
0answers
14 views

What is T_e in stepper motor equation?

The description for T_e is missing on this page. Source: https://se.mathworks.com/help/physmod/sps/ref/steppermotor.html
0
votes
0answers
42 views

How to allow input on bits of Microcontroller port

I'm trying to figure out this question: Write a line of code in C to allow input on bits 2 through 4 of port A. I am familiar with writing code, I just don't understand the question. Can someone ...
0
votes
1answer
30 views

Exceeding voltage on STM32 Vbat pin

I want to power STM32F429 Vbat pin with an existing Lithium Ion battery on board. However, the maximum voltage on the discharging curve of this battery is 4.2v which is above the maximum operating ...
0
votes
2answers
66 views

Offsetting Voltage from 2.5 V to 0 V without Effecting gain

I'm trying to digitize a Hall Sensor whose center voltage is 2.5V and the gain it's output is 1.5V to 3.5V, or ±1V. My digitizing card's center voltage is 0V and I would like to get the full range of ...
0
votes
1answer
38 views

5 V from power bank not constant when supply circuit

Now I'm working on my project which contains Arduino, LCD, electromagnetic lock, 6 channel 5v relay and 500V isolated converter. My project was designed to power by using a power bank. Now I use eloop ...
0
votes
0answers
12 views

How do I wire in a capacitor into an LED circuit to eliminate a flicker issue? [migrated]

I have led running lights on my truck (with a resistor already inline) and am encountering a flicker issue ONLY when the engine is running. I was thinking a cap would fix it.
0
votes
0answers
14 views

+24VDC to 5v converter - does the positive make a difference? [migrated]

I have a fairly general question, but cannot seem to find an answer to confirm my thoughts. I have a garage motor door, and on the top has 4 terminals - 1 and 2 for a switch button to open and close, ...
-4
votes
0answers
84 views

Lead Contamination in house after touching solder [duplicate]

I may have accidentally touched my laptop and keyboard and mouse and maybe my desk after soldering the one time I did and was wondering if it's contaminated with lead and how to clean/dispose of it if ...

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