All Questions

0
votes
0answers
22 views

How to combine a charger for LIPO battery with a boost step-up voltage converter?

I want to power a device with up to 4A at 5V from a single-cell LIPO battery of 3.7V 5000mAh and be able to charge it. The idea is to have everything packed up inside a case, so I don't want to rely ...
0
votes
0answers
35 views

pcb-4-pin passive crystal is soldered to a 2-pin crystal PCB package

I would like to know whether it is suitable (not harmful) to put a 4 pin passive crystal in a 2 pin footprint. Thanks in advance.
0
votes
0answers
28 views

my LM35 temperature sensor gives weird measurements, [migrated]

Board: esp32 I know my wiring is correct because I get data from the sensor, but the data is a bit weird. At 22 celcius I get 140, even though if I do the voltage calculation (* 0.473372) it still ...
0
votes
0answers
22 views

RF device connection issue

I have a surface acoustic wave based separator device built on piezoelectric (PZT) substrate and this is mounted on a PCB for the external connection as you can see from the picture. When I was ...
-1
votes
0answers
25 views

How to find force pull solenoid

Sorry for the previous post that was wrong. I want to know F=(NI)^2*μ0*A/2L^2. What is the cross-sectional area? Reference.
0
votes
0answers
28 views

150 A 12 - 16 V DC Short Circuit Protection

I am powering a ROV from a 4S LiPo battery (12.0 V minimum, 16.8 V maximum). The resistance of the battery is 36 mΩ, so that a maximum current of 470 A can flow through a short-circuit. In order to ...
0
votes
0answers
24 views

Getting positive and negative DC voltage from an 230 Vac power supply

I am trying to build a power supply and control circuit but I need both positive and negative 5 Vdc to power the device and 0-1.1 Vdc to control the gain. How can I get the positive and negative 5 ...
0
votes
0answers
25 views

Driving an XLR input with virtual ground

I am building an audio circuit. I would like it to have XLR as an input (as well as others). It needs at least 12 Volts to operate. To drive my operational amplifiers, I am using a rail splitter with ...
0
votes
1answer
36 views

How to select the best opamp for a constant current MOSFET driver

I'm trying to create a constant current LED driver. I have found and read information about the miller effect and came up with the schematic below. What are the most important parameters for choosing ...
0
votes
0answers
32 views

Debug uart serial communication on nucleo l010RB [on hold]

I want to implement an UART interface on Nucleo L010RB. I am using a project inspired by the examples provided by ST as there is none for the board I am using. I am using this data format: 8N1. The ...
0
votes
0answers
29 views

Video transmission using microcontroller [on hold]

I try to stream video using a microcontroller. I tried Raspberry and it was expensive and boot time was very slow (which is crucial for my project). I didn't try arduino because I assume it wasn't ...
-4
votes
0answers
20 views

Interfacing RFID reader directly with computer [on hold]

Can I connect RFID Module directly to PC without MAX 232 IC
1
vote
0answers
39 views

Noises of switching power supply

I made a switching power supply (input: 24VDC, output: +-15Vdc) for LEM (current sensor). Noises of the power supply caused the output of LEM to become a bad waveform, but I don't know how to ...
0
votes
1answer
30 views

Dysfunctional IRF9540

simulate this circuit – Schematic created using CircuitLab I am trying to build my own SMPS and I was intending on using a P-Channel MOSFET for high side driving the main circuit. The MOSFET in ...
0
votes
1answer
33 views

Ouput resistance of a charger

I want to measure output of a charger (MODEL: GB28-25126) with below picture: When I connect my HIOKI multi-meter (3280-10F) to output of my charger in order to measure the resistance, it shows OF (...
1
vote
3answers
68 views

Help identifying an SMD component [duplicate]

I need help identifying an SMD component it is a small(1 mm X 1.5 mm) black part with an "O" written on top if it. I think it is a Schottky diode for reverse polarity protection ?. (Source, first ...
-1
votes
1answer
29 views

Driving Triac With MOC3021 for 12 v ac

i am using triac bt136 with moc3021 to drive 12vac but i found the problem is it possible to drive the triac on 12vac i made the circuit as shown in link on 12 vac but i didn't get any exact sine ...
2
votes
2answers
115 views

What, Why dual power supply?

My question is what is the difference between +12v and -12v. Can anyone explain it with a practical example approach. can any one explain the real need of negative voltage(-9v). please try to ...
-4
votes
0answers
43 views

Old tube amp from a Baldwin organ [on hold]

Hello to all and thanks in advance for any help .. ok well I have this tube amp its complete I have everything out of the unit .. I'm very curious about making this I to an audio amp for my home ...
5
votes
5answers
729 views

Reasons for having MCU pin-states default to pull-up/down out of reset

On many MCUs, pin-states default to tri-stated (a.k.a. analog inputs) when the MCU resets so as to not affect the circuits they are connected to until software configures the pins. The tri-stated ...
0
votes
1answer
32 views

Class D Amp headphones grounding circuit

I am having a problem with some of the class d amps I've played with (PAM8302A), and it seems like this article here describes my problem: https://www.edn.com/design/analog/4313726/Add-headphones-to-...
2
votes
1answer
59 views

Finding the broken cicuit in an Xor Gate

I am new to this particular stack site but I feel that this is the most appropriate place to ask my question. -Background- I've been following an online web course called Nand2Tetris that takes you ...
0
votes
1answer
41 views

Impact of capacitor on half-wave ac to dc rectifier

I'm trying to convert 24AC from a furnace into a DC signal I can step down to power a 5 volt microprocessor. Following this blog post I bought a 1n4002 diode and a 220 uF capacitor. Then I built this ...
0
votes
0answers
81 views

What am I doing wrong? (Basic circuit excercise)

I've tried to solve this circuit and I get that Iy and I5 are 0 A, and this can't be possible since Iy is a current source. What am I doing wrong? The second KVL equation englobes the whole circuit. (...
0
votes
1answer
55 views

DC Current Measurement (resolution of ~ 1 uA)

I haven't worked with electronics in a long time, and now have the task of measuring the power consumption of a low-power device I'm writing firmware for. I hope my question makes sense.. When the ...
1
vote
2answers
44 views

Thévenin's Theorem Example

I just started learning Thévenin's Theorem. My textbook gives the following example: I'm referring to online sources such as this to complete this problem. However, all of the circuit diagram ...
0
votes
1answer
49 views

BJT differential amplifier: What causes common mode voltage gain?

In any normal op amp, if it was ideal it would have a gain such that the output voltage would be However in reality this is not the case as there is a common mode voltage gain and hence in reality ...
4
votes
1answer
348 views

What is the chip with this PN?

I have one IC for which I can not find any clue for the part number (PN). It has "BA7P16" and "5810" on it. What manufacturer has that logo and what chip is it?
0
votes
0answers
32 views

Implement Digital Logic with Edges

I am looking for some kind of pin channel selector design for 16 signals, 0-5V. When a specific signal got high, I should get its number (address) over a 4 pins address. No simultaneous highs will ...
1
vote
0answers
40 views

How do I calculate this inverse Laplace Transform

I have this transfer function and input, and I have to manually calculate what the systems response will be. The transfer function is: and the input is: I multiplied the two functions and used ...
0
votes
1answer
27 views

MSP microcontroller Watchdog timer

I am new to programming microcontroller. what does the following like of code do: WDT_A->CTL = WDT_A_CTL_PW | WDT_A_CTL_HOLD i have looked at the technical ...
0
votes
0answers
34 views

Converting Pulse Sequence Inputs Into Separate Outputs

I'm trying to find the simplest way of accomplishing the following task: Convert 3 different pulse input sequences into one of 3 different output lines The image below explains the problem ...
1
vote
1answer
77 views

Why would Discontinuous Conduction Mode be desirable for an LED driver?

I saw this press release where DCM was listed as a feature for a new Infineon driver chip. Source: led-professional.com I'm involved in LED driver design for Horticulture where DCM is undesirable....
0
votes
0answers
22 views

Concurrent DMA streams handling UART

I've currently got a STM32F777VI microcontroller working with UART receive working through DMA. The problem starts when I try to receive data from 2 UART peripherals using DMA. According to the ...
0
votes
1answer
40 views

Does a common neutral between solar inverter and utility affect current measurement?

I have solar hybrid inverter at home that's connected to the mains using both, the line and neutral wires. However, to save the costs, I've connected the load to it using a common neutral i.e. I've ...
0
votes
0answers
50 views

Would a device with different power rails become one if both rails are shorted to ground

I'm trying to repair a nintendo switch that seems to have multiply shorts to ground. The shorts to ground are on the 3v3 rail and on the 1v8 rail. I seem to be getting continuity between the two ...
1
vote
1answer
36 views

Is the system y[n] = x[n] + x[n-1] invertible?

Is the system y[n] = x[n] + x[n-1] invertible? If yes, what's the value of x[n]? If no, could you please introduce a counter ...
-1
votes
0answers
18 views

Simple 5-6S lipo battery system for diy speaker

I'm building a Bluetooth speaker based on this YouTube video, but I want to have a integrated battery system with charging/power from 12V. Could someone tell me how to do this safely with Li-Po, BMS, ...
0
votes
2answers
61 views

Elimination of interfering voltage

I have a problem deriving a formula I will be using in my bachelor thesis. It's about eliminating interfering voltages during measurement. To understand how the interfering voltage is going to be ...
-1
votes
0answers
23 views

MOD 16 counter with adjustable MOD [on hold]

Is it possible to design a counter where the user can choose the MOD? The maximum that can be selected is 16.
0
votes
0answers
75 views

Help identifying a variable resistor's function

I have recently acquired a TC Electronics Tube Pilot guitar effect pedal. While exchanging the vacuum tube in it, I noticed that there was a 22k ohm variable resistor on the board. Can anybody tell ...
1
vote
2answers
99 views

How to check whether a byte of 8 bits contains 1, assembler 8051?

I need to know how to check whether a byte contains a 1 for touch status in a MPR121 project, so if: 00000010 then pin 2 is touched 00000100 then 3 is touched, how can i know it? A set bit means that ...
1
vote
1answer
25 views

Where is the boost converter in Cypress PSOC 5LP CY8CKIT-059 Prototyping kit?

I have been using the boost converter (dc-dc converter) of "PSOC CY8CKIT-050 development kit" for a time, but I wanted to use the one in PSOC CY8CKIT-059. Nevertheless, I didn't find the boost ...
0
votes
0answers
21 views

Output voltage for pmos with Vt= -0.8

simulate this circuit – Schematic created using CircuitLab What is VX? I am having confusion between 2.8 V or 3 V. Thank you for your help.
2
votes
2answers
67 views

Light sensors sensitive enough to detect for PWM from CF and LEDs?

I have an extreme sensitivity to PWM light sources such as computer screens and light bulbs. This can make it very challenging to make a purchase as I end up having to do lots of guesswork with ...
1
vote
3answers
75 views

7432 behaves like an AND gate & 7408 behaves like an OR gate

Ok. First of all, I'm an absolute beginner about IC and circuits. If you will view the pictures, you will notice that the 7432 behaves like an AND gate and the 7408 behaves like an OR gate. PS. I ...
3
votes
3answers
336 views

Difficulty understanding group delay concept

I’m having difficulty understanding the concept of group delay. The mathematical definition is not difficult, since it says it is the negative derivative of Bode plot’s phase curve wrt frequency. Most ...
0
votes
0answers
38 views

Find force pull solenoid

Sorry for the previous post that was wrong. I want to knowF=(NI)^2*μ0*A/2L^2 A What is the cross-sectional area? NewRef.https://www.researchgate.net/publication/...
1
vote
2answers
35 views

Use a TRIAC to connect/disconnect a capacitor to a PSC motor

In the image above, we see a PSC motor, with its 3 terminals, connected to a control board. This board has a RUN capacitor always connected to the motor. When the motor has to turn, the board applies ...

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