# All Questions

115,508 questions
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### High voltage and current

I have a DC motor that needs and works nearly 400v and 20A. I chose FDL100N50 for n-channel mosfet also IXTK40P50P for p-channel mosfet. I connect a 4n35 optocupler for output of every mosfet. Are ...
10 views

### Multistage Audio amplifier with gain 175

I need to Design the audio amplifier with following specifications . I am going to design for the first time and I don't know what sort of transistor should be used how should I start . Any tips . ...
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### Superposition with dependent sources

If the value of a dependent source (say CCCC) depend on the value of an independent source (say a current source). When setting the current source to 0, would that make the CCCC an open circuit (i.e. ...
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### Equivalent Circuit of Howland current Pump

Why is at norton circuit for Howland current pump the current source is taken as vi/R1 instead of vi/R0? Because the formula for Norton current is IL=In*(Rn/(Rl+Rn))
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### Wheatstone Bridge Single-Element Varying

So, this book is saying that when V_B is 10V, R is 100ohms, and delta R is 0.1 ohms, The linearity error is 2.5mV - 2.49875mV = 0.00125mV. I don't quite understand where 2.5mV came from. If I use ...
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### RFID UID vs “card number” on cheap chinese cloner

I built an RFID reader using the RC522 with an arduino. It is working great and when I scan the card that came with it it tells me the following: - Card UID: C1 44 53 63 Card SAK: 08 PICCtype: ...
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### Don't able to program ATmega2560

I have developed custom PCB based on ATmega2560 microcontroller. I'm not able to upload code to ATmega2560. I'm using USBasp programmer and ProgISP to upload hex file. Programmer and ProgISP are ...
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### Why do not we just decrease the voltage?

why do not we just decrease the voltage instead of pulling down a resistor to ground the `68k Ω' I don't know much about this so I'm just learning since the op-Amp LM324 is just checking V1 and V2 ...
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### why L298N driving the motors properly on battery but not on adapter?

I am using Arduino, l298n, adapter(12v,2A) to drive the motor 12v,200rpm when I test the L298N by simply making high and low using jumpers the motor works fine but when I connect the jumper to the ...
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### Plotting bode plot, how the starting gain is in negative?

For function; $H(jw)=10jw/((1+jw/2)*(1+jw/10)$ To find starting gain, i did, $20log(10)$ which equals 20, but in matlab, it shows ...
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### On a 3-terminal bench power supply (+, -, GND), are there positive and negative drivers behind each of the terminals?

In a 3-terminal power supply like this, are there individual regulators behind the positive and negative terminals? For example a LM317 on the positive and a LM337 on the negative? If not, what kind ...
48 views

### Word length in a computer system

i am currently reading about memory system in computer architecture. I wanted to know, Is the word length the number of bits input to the ALU?
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### Using internal regulator DVDD pin to power up external devices

I am designing a H-Bridge PCB and using DRV8323 as the driver. This chip has a pin name DVDD which from my understanding, from the below statement, is used to ...
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### Allowing different inputs without needing to alter gain every time; a situation for a pre-amp?

The goal I am attempting to make a small diy bookshelf speaker system using 2 16ohm, 25 watt speakers and a 2x25 watt class d amplifier board. If it matters, the amplifier board is a class d amplifier....
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### Reusing speakers from an old laptop: how to amplify them?

I would like to reuse two pair of speakers got from an old ASUS 1201T laptop. Since I don't know the specifications of the speakers, I looked in the datasheet of the Realtek ALC269 sound card and ...
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### Resistive Divider

In a nutshell, the book says However, I don't see how that's true. If I re-draw that resistive sensing part as follows: Surely, isn't it just Why do I have a minus instead of a +? EDIT: I just ...
102 views

### Moving brute-force search to FPGA

I am currently working on a scientific hobby project about computing the error detection capabilities of CRCs. Unfortunately the C++ code used for such computations has up to years of run time on ...
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### How to calculate resistivity from this cell design?

I was wondering how/which area and distance values are calculated for a concentric 2 electrode conductivity sensor (below) when trying to calculate the bulk resistivity of a fluid. The blue is the ...
25 views

### 8051 Open Drain Operation

While studying I ended up finding this question. Write the value (in hex) of the P1 after the execution of the code below. ...
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### Can a stepper motor driver run if powered using a lower voltage than its minimum voltage?

I have a stepper motor driver with input voltage(24-50 V DC) .can I use 12 DC ? what effect will under powering the motor stepper driver have? NOTE: i have stepper motor with 45 kg.cm .in practice, i ...
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### Can I programme modicon m258 plc with codesys [on hold]

Good morning, I know that modicon m258 plc is programmed with somachine. But it's a licenced software. So can I programme the modicon m258 with codesys
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### Atmega168 USART RX Interrupt does not trigger

I have been trying to get the USART RX interrupt trigger working on my ATmega168A using the tutorial here (updating my registers as per the datasheet): Tutorials I have setup the system to use a ...
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### Turning off the LM3914 dot/bar display driver per the datasheet

I'm designing a circuit with an LM3914 dot/bar display driver and want to shut off the entire bank of LEDs based on conditions in the circuit. I'm having some difficulty turning off the driver from ...
83 views

### explain the working of this circuit

I'm basically trying to understand how this Dc to Dc step-up converter work. please help me.[![dc-dc step-up voltage converter 1v-9v][2]][2] I need to design a DC DC step up converter using bjts. ...
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### Circuit Choices for AmpIifier Input

i have breadboarded a TDA2050 amplifier, using this schematic i get good sound intensity with a half acceptable quality. the down side is the constant noise and humming. i have found a possible ...
27 views

### How does the flux de-oxidize the outer most layer? [duplicate]

The copper's outerlayer is oxidized and the flux's job is to remove it and the impurities. But what type of chemical allows the oxidation on the copper to be removed? How does the flux remove the ...
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### Small 12V DC-Motor Non-Linear Torque vs. Current Curve

I am currently investigating a malfuction on 12V small electric motor. it is performed torque vs. current measurements on a group of samples and some of them are showing non-linear current i.e ...
52 views

### What is the least expensive way to build a three-bit shift register?

I'd like to build a queue of three internal bits as inexpensively as possible. Externally, the queue has two input bits and one output bit. The inputs are (dataIn) and (shift), and the output is (...
56 views

### I cannot figure out what kind of transformer this is [on hold]

So I was told this is from a welder but I would like to us it for fractial wood burning but I cannot figure out what kind of transformer it is and how to do it, all the videos use microwave ...
31 views

### KVL Issue - Telescopic Casocde Amplifier

Hi, my question is regarding the equation circled in red in the highlighted text above. I can't seem to understand the reasoning behind why all the transistors are included in that equation. My ...
51 views

### Photodiode - circuit questions

I am a bit confused on a few things regarding photodiodes. Here are two circuits that I am referring to: or   For the second circuit the capacitor is not of importance. Here are my fundamental ...
22 views

### How to convert a RS-274D gerber to RS-274X

I got from a website some gerber files, I tried to have them printed, but they told me that the format is not supported and I need to convert to RS-274X. I've tried using gerbv to open the gerbers ...
69 views

### Simulating a Buck converter

Im trying to simulate a buck converter done in class to see if this fits what the theory says it would be, It must receive 110 V and send to the load around 60V and 20 A, the circuit is: And with ...
85 views

### Is the US Power grid's voltage the theoretical maximum? [on hold]

At this point, most of the people on this site who live in America know that the voltage of common power circuits is around 120 volts. My question relates to the use of voltage dividers in a circuit. ...
51 views

### PIC32 Real Time Clock and Calender. What is a use case?

I have observed that some PIC32MX micro-controllers have an inbuilt RTCC peripherial. The first feeling i had when i saw this was joy, as it meant i could eliminate a component of my PCB. However ...
41 views

### Proportional Control Balance Beam

Bit of an unorthodox question I'm sure, but I'm making a balance beam (two rotors on either end of a see saw) with proportional control, and I can't seem to get it to balance at 0. The proportional ...
56 views

### Ammeter scale, not sure what my amp reading is

I have a basic multi-meter that I am using to measure amp on a load. I am trying to figure out how much amps my small entertainment system draws. (LCD TV, PC, speakers.) I want to build a small DC ...
38 views

### Operating AD5780 EVAL Board Via MicroController

OK, so thanks in advance because I am new here. I am reading the AD57XX drivers here https://wiki.analog.com/resources/tools-software/uc-drivers/renesas/ad5780 and am struggling to understand how to ...
31 views

### active pfc circuit

I have come up with a bridgeless active pfc circuit. Does this arrangement make sense? When M1 and M2 are on, the inductor current ramps up until M1 and M2 are turned off. No current flows through ...
42 views

### How to mount four 6-wire 10V load cells on Arduino or Raspberry Pi?

I want to connect four 6-wire load cells (Tedea Huntleigh Compression & Tension Load Cell 300kg, 15V dc, IP67, product page and datasheet) into an Arduino or Raspberry Pi and get four independent ...
34 views

### Single Clock FIFO with Single Port RAM

I wanted to make use of a single port RAM to be a single clock FIFO in verilog for an asic project , due to some constraints i can not use the dual port RAM. My confusion is when I have to perform ...
55 views

### What does Minimum Slot Aperature mean?

Exploring some fab houses and I came across this statement from https://www.viapart.com/PCB/Explain "Minimum slot aperture Mechanical drill 0.6mm The tolerance of groove aperture is±0.1mm" Does ...
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### LTM8073 integrated DC-DC buck converter issues

I have a board with two LTM8073 "silent switcher µModule regulators" by Analog Devices/Linear Technology being used to provide two separate power supplies. This is a 10-layer dual-sided board that was ...
42 views

### Switch for low voltage, high current Shape Memory wire

I need a switch to allow current to pass through a wire to Joule heat it. This is a nickel-titanium wire (Shape Memory Alloy, SMA) which has been programmed to bend into a particular shape when heated....
60 views

### Control GPIO pins using USB

What is the easiest way to make a device that can control GPIO pins using USB? Can I make a device similar to this on my own without any special hardware?
31 views

### Shape of a core for use in a solenoid

I am currently designing an electromagnetic accelerator meant to accelerate a spherical nickel-plated NdFeB (neodymium) projectile along a circular tube, in a similar manner to a particle accelerator. ...
65 views

### How is this equation valid?

I am trying to understand the Howland circuit.But how is the following equation formed .Isnt it should be(vi-vo)/R
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### Firmware only runs when I press the reset button

I've created a board using the STM32F405R6T6. I am experiencing some problems: after I program the firmware onto the microcontroller, withdraw the power and reinsert, the firmware only starts to run ...