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working of lm386 ic

i am not an electrical engineer , but i am curious enough and my mind tells me to make a radio circuit , and now i am into it , so to make one , i need some components , but before that so that i can ...
0
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0answers
8 views

PIC24FJ1024GB610 MLA USB Device Lite USB stack stops working when multiple endpoints are enabled

I'm using a PIC24FJ1024GB610 and have configured the "MLA USB Device Lite [USB Framework Lite]" using the Microchip Code Configurator utility. The Microchip Lightweight USB Stack settings ...
2
votes
1answer
40 views

Can i make dram using bjt transistors? [closed]

Is it possible to make dram using bjt's or is it only possible with mosfet's? If not why not? Is there an advantage in using mosfets instead of something like a bjt ?
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0answers
25 views

Do I need to replace removed parts with a resistor?

I have some external hdd-drives. Their cases usually have a led and sometimes a fan. If I want to remove e.g. the led or the fan, do I need to replace them with a resistor? I am aware that removing a ...
0
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7answers
81 views

Why does voltage drop across resistance contradict ohms law?

Very basic question here, I have been Leaning a ton About ohms law, and I don’t seem to ever be able to completely understand it. One of which I am getting particularly confused about is voltage drop ...
0
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1answer
13 views

Damaged OLED LCD voltage regulator replacement

I have a 128*32 OLED LCD that is used with an Arduino. I recently damaged the voltage regulator and was hoping to be able to repair the board by soldering off the damaged component and replacing it ...
0
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1answer
12 views

FTDI and ST LINK devices together to STM32

I have an STM32 board (blue pill) that I am programming with the Arduino IDE. I couldn't program it using an FTDI adapter because I couldn't make the Arduino IDE communicate trough the USART for ...
0
votes
1answer
29 views

Can a resistor mitigate a maximum input voltage limitation?

I have a microcontroller running at 5v and outputting a digital signal. This signal can be high, low or high-impedance (tristated). This signal goes to an input pin on a target chip (the type of which ...
0
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0answers
40 views

what is 1 volt and 1 ampere? May sounds very basic but its deep. please help

Facts: Charge, or more specific electric charge, on 1 electron is -1.6 x 10^-19 Coulomb One has to do some work to get electron from its outer most orbit. It can be room temperature as well. Current ...
0
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1answer
12 views

Matching line driver output impedance over wideband

I'm designing a high impedance line tap for 10-10GBASE-T ethernet signaling. In the AFE I have a JFET LNA for high input Z which goes to a var. gain amplifier that is a fully differential ADC driver. ...
0
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2answers
47 views

How filterless Class-D amplifier works?

The image below shows how a Filterless Class-D amplifier works: The way I understand it: Vout(minus) is just the mirror image of the Vout(plus) but there was a certain phase shift(time delay?) ...
0
votes
1answer
24 views

Connecting a TCXO to logic buffer

I am trying to connect the O/P from TCXO (FOX Electronics FOX924B. 20Mhz, 2.5PPM, 3.3v supply, Output HCMOS VOL=0.5V and VOH= 80% of VDD) to 74HC240 buffer, which I also running at 3.3V. I am not ...
0
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0answers
26 views

How to receive a startup hex string during a debug session?

This is my setup: I have a 'smart display' connected to the serial interface of a PCB with a PIC microcontroller. The PIC powers the smart display. This smart display uses a boot mechanism. When the ...
1
vote
1answer
32 views

Can you dim already dimmed LED lights

Ive installed LED downlights in my room, these : https://www.screwfix.com/p/lap-fixed-led-downlight-contractor-pack-white-370lm-5w-220-240v-10-pack/728fj they are controller via a smart dimmer switch, ...
1
vote
0answers
36 views

How to convert this circuit to DC?

Premise: I'm a total noob. This circuit can be connected to the wall power source via its riser, connected to VCC, GND, S- and S+. You can see in the background a battery, connected to B+ and B-. You ...
-1
votes
3answers
53 views

Is this analog switch good for UART lines?

Currently designing a circuit to switch between two UART lines using an analog dpdt switch. Been searching for a while and found the BL1532. The datasheet says it's a DPDT USB2.0 Analog Switch, but ...
0
votes
0answers
31 views

Is ROC of Laplace transform of a right-handed signal right to the rightmost pole?

I know that ROC of a right-handed signal with a rational Laplace transform is right to the rightmost pole. Does it apply to any right-handed signal?
0
votes
1answer
37 views

Position components in KiCad for a test rig

I'm designing a test rig for a product. There's a number of test pads and a power connector on the PCB, which I want to match up with a tester device, i.e. the tester PCB should have pogo pins and the ...
0
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0answers
16 views

How to make test bench to test schemetics in cppsim [closed]

Format for creating schematics: project_xName_ Format for creating test bench tb_xName_
-4
votes
1answer
60 views

Which wire is best for solenoids [closed]

I am not an engineer but I want to make a small radio circuit. Which wire would be good for its coil.
0
votes
2answers
74 views

How do you connect alternators in series?

What does the circuit diagram of three phase generators connected in series look like? I know they are usually connected in parallel for obvious reasons.
1
vote
3answers
60 views

Controlling Z axis placement

What techniques are there for placing the components on a PCB at a desired height? e.g. so that potentiometers and switches can be both panel mounted and board mounted? For example, are there adapter ...
0
votes
0answers
54 views

Why ferrite core transformer not giving output? [closed]

I set the Bmax level below saturation level ,used handmade litz wire still not getting desired output. I am expecting 50KV at 50 kHz.
0
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0answers
57 views

How many flash drives can you power with an iPhone battery?

I will give a very specific example: Hardware: Iphone X device with 2716 mAH capacity battery, 3.81V Iphone "dongle" lightning to USB 3.0 port, bus-powered USB hub 3.0, bus-powered, 3V, 200 ...
4
votes
2answers
77 views

Need help with reading mosfet datasheet (safe operating area graph)

What does indicated time in below graph means? datasheet
0
votes
2answers
45 views

How do you split a summing point into two?

I am solving a control system example on block reduction rules and stuck on this particular step. According to me, I can move the summing point ahead of the middle block to get G4 multiplied to both ...
0
votes
1answer
35 views

Instrumentation Amplifier Gain set resistors

We are looking for Instrumentation Amplifiers for an application.  At this stage, we have decided a certain gain value for our Instrumentation Amplifier. The datasheet of the product mentions the very ...
0
votes
2answers
50 views

Sensor for Weight Measurement

I want to measure weight of some objects which range from 50 grams to 20 Kg. So what kind of sensor should I use to get values with a precision of 1 gram. I tried a strain-gauge load cell of 20Kg, ...
0
votes
2answers
34 views

Isolated RTD sensor

I need to read a Heatsink temperature with 5KV isolation. how is it possible? are there isolated temperature sensors ? or shall I design a board for it to isolate the output signals?
0
votes
1answer
10 views

KSZ8081RNACA phy address setting up

I have following PCB design, which use PIC32MZ2048EFH144 and KSZ8081RNACA, I want to set up phy address to be 3. From document it has following words "Config Mode: The pull-up/pull-down value is ...
0
votes
1answer
36 views

2S 10C LiPo 6000 mAh step-down to 6V

There are a ton of buck converters that can step-down 7.4V to 6V. But looking at their specs, all of them can't seem to handle the typical LiPo high current discharge rate of say 60A. Is there ...
3
votes
1answer
252 views

What is the meaning of this schematic symbol (labelled COMP.J1 JPAD3)

I am trying understand the schematic for a Waveshare Core 407I board, with an STM32F407IGT6 MCu. What is the meaning of this schematic symbol (labelled COMP.J1 JPAD3)? Link to full schematic: https://...
0
votes
0answers
39 views

stm32f401 usart: start bit detection sequence when oversampling by 8

I'm currently using usart on stm32f401. I'm wondering how the receiver detects start bit when oversampling by 8 is selected. The reference manual (RM0368) states that the start bit detection sequnce ...
0
votes
1answer
32 views

BE QM marking SMD component

Working on a board currently, but cannot find any info on what kind of component this is. I have some suspicion/intuitive feel, but I`d like to be sure. It appears to be a SOT 89 package. Anyone ...
0
votes
2answers
66 views

wiring up laser pointer directly to usb power

I have a red cheap laser pointer/lantern which I'm using to do some experiments. But I find that the batteries have a very short lifetime for what I'm doing, It uses three LR44 button cell batteries, ...
0
votes
0answers
16 views

Seemingly having trouble setting an ISR interrupt greater than configMAX_SYSCALL_INTERRUPT_PRIORITY

How does one set the priority of an ISR when free RTOS is ebing used? So I have an ISR for push button that I'm setting to a higher value than ...
1
vote
0answers
42 views

How to bypass step-up voltage converter?

I bought this great solar panel unit on amazon that has lithium batteries, 12v input and 12v output. I use it to power a 5v ESP8266 and I have a step down voltage converter from 12v to 5v on my end ...
0
votes
1answer
25 views

RF Matching Net

I am projecting a system that contains two RF chips, a LoRa SX1276 (915MHz) chip and a ESP32-D0WDQ6 (2.5GHz). In the schematic bellow, the ESP32 (2.4GHz) design has a matching net between the chip ...
0
votes
2answers
54 views

Unknown indicator of package specification

I am creating the footprint of an IC, and the manufacturer has specified this below: I cannot figure out what C0.3 stands for. Is it the length of the diagonal? If it helps, according to another ...
1
vote
1answer
38 views

How to calculate Pi filter for RF with PCB antenna - Nordic nRF52832

I have finished the layout of a bluetooth beacon based on SoC nRF52832 of Nordic, there is a Pi filter between the IC pin and the antenna that use the AN043 drawing of Texas. AN043: https://www.ti.com/...
0
votes
1answer
29 views

Power tree understanding

I am projecting a brushless motor driver that contains a LoRa SX1276 radio and a ESP32-D0WDQ6 chip. The power line then gets really noisy when everything is working. For the RF blocks (SX1276 and ...
0
votes
2answers
69 views

Adjusting Potentiometer Range

I'm using two 1K potentiometers and I want to achieve this result: When the first pot is set to 1K (100%), adjusting the second pot should change the output from 0 to 1Kohms. When the first pot is set ...
0
votes
0answers
52 views

Signal generator design [closed]

I need to construct a signal generator (DC), that can provide a square wave signal of 5V at 50% duty cycle and frequency of 0.125 Hz. What would be the best option, considering this situation? ...
1
vote
0answers
23 views

voltage monitor using tps3897 - understanding

Although I have some experience with circuitry it is mainly analog experience. therefore I can't solve the question i have been given in interview. I have been asked what does the next circuit do: ...
0
votes
0answers
57 views

How to create phase (hot) and neutral in single phase inverter?

simulate this circuit – Schematic created using CircuitLab I have made a single-phase 50 Hz-220 volts (RMS) inverters. I thought that one of the outputs will be hot and another one will be ...
1
vote
2answers
27 views

Passive (energy harvesting) tag / transponder chipset solution with 12 inches range?

I've been using a 134.2 KHz (FDX-B, ISO 11784/85) transponder/reader for use with implanted and pendant tags. However, I've been frustrated as to the range. Is anyone aware of a chip/circuit level ...
0
votes
3answers
52 views

Which cable connection will result in a greater loss of power?

I know that running a power cable (the cable is carrying 5V DC, I plug in an AC to DC converter to the mains) that is, for example, 50m will cause losses in the power output. So if you measure at the ...
0
votes
0answers
15 views

How to run TTP223 Module on AC supply?

My question is about TTP223 module. It is operated on 3-5 Volt DC. But how can I run it on AC supply? I mean I don't want to use DC source. I want to run MOSFET instead of Relay by this.
1
vote
3answers
75 views

SRAM/DRAM Price Difference

An SRAM cell uses 6 CMOS transistors to store 1 bit of information. A DRAM cell uses 1 transistor and 1 capacitor to store a bit. So one could guess that for the same amount of information (say, 1GB), ...
2
votes
3answers
490 views

Some basic questions about an accelerometer's unexpected behavior while tilted

I have an ADXL335 accelerometer connected to my Arduino. Here is some code that I am running based off a tutorial: ...

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