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I'm attempting to create a 555 timer oscillator circuit, in which the rising and falling delays of the generated clock signal are independently controlled by two analog input signals. As an initial ...
Runsva's user avatar
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I am looking to better refine a design I have for a circuit that switches between two voltage sources: one stable (3V) and one variable (1V-5V), and I would like to be able to control the rise/attack ...
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Is it possible to design a circuit that acts like a resistor, but whose resistance is inversely proportional to the square of the voltage supplied at the input? This circuit would have one input and ...
Runsva's user avatar
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The value of a rotatory potentiometer is 1K. It is connected to a 5.1V power supply. The output values from centre of potetntiometer with respect to the angle are given below: 70° - 1 V 145° - 2.04 ...
Rajesh R's user avatar
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I have been working on a design for a surface mount practice kit for electronics students. I am a trained E tech, have a minor in EE and BS/MS in ECE with a focus on opto-electronics so PSU and PCB ...
Antone Bajor's user avatar
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I want to design a variable output regulator to convert 12V to -10V to 0V @1.5A. My idea is to convert 12V to -10V using an LTC7149: I have 40mV ripple at 1.5A. I need to reduce this ripple as much ...
Andromeda's user avatar
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Is there a way to create a variable analog multiplier using conventional op amps? I've been trying to wrap my head around analog multipliers, and I haven't been able to come up with a reliable answer ...
paraparabolic's user avatar
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I have for several years now been interested in CRT (Cathode Ray Tube) displays and the science behind them. I do not have a large amount of electrical engineering experience, but I've learned enough ...
ingx24's user avatar
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I am working on a small project using a cheap chinese MP3 player module, that can be triggered to play an mp3 by just sending it a pulse on one of its inputs. The modules are of this type: https://nl....
just me's user avatar
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I have three motors connected to a high pressure misting system. One motor is variable and is sized about 20% larger than the other two motors. They are on-off motors. All three motors work in tandem ...
Geo's user avatar
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2 answers
155 views

Variable capacitors are used less, since the preference is for digital adjustment. And through hole parts are used for less, since the preference is for SMD. Finally, many variable capacitors have ...
SRobertJames's user avatar
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I want to use a variable non-polarized capacitor which can vary between 10 pF to 1 μF, or at least up to 100 nF. I can only find trimming caps which can only go up to 100 pF. Am I looking for ...
pnatk's user avatar
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I have a basic tone generator circuit with LFO speed controlled by a 50K pot (variable resistor). I would like this resistance to fall (or rise, but I guess fall might be easier) after the circuit has ...
Jeff's user avatar
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I'm wanting to build a variable voltage-controlled resistor. The resistor would be in series with a 200 uA AC current source and need to be controllable between 1-20 ohm. My current plan is to take ...
Mekala's user avatar
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1 answer
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I have 440V 3 phase power that will be full wave rectified to 600V DC. My question is, would I be better off plucking one of the phases and rectifying the 120V AC to 12V DC or one of the DC rectified ...
ircsmith's user avatar
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I'm trying to understand how this topology of state-variable filter with summing amplifier produces a band-pass filter at the second integrator's output, in the context a parametric audio equalizer. ...
Domingo's user avatar
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Just for fun I want to make a lightweight, cheap, adjustable positive/negative bench power supply. "Lightweight" means that using an old PC ATX power supply isn't suitable as a basis. ...
Mike S's user avatar
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I am trying to understand how to get values at midpoint_diode and also at OUT. I understand this circuit is to step-down the voltage from Vin to something that is lower and also it used to have a ...
mdabdillah's user avatar
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First, the background context: I have a pair of these TCS-300 landscape lighting controllers which have a cloud-only control interface, which cannot be integrated with my local home assistant. My goal ...
Wez Furlong's user avatar
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I'm trying to start learning about electrical engineering as a hobby. I'm reading from a book right now, and it suggests using my multimeter to measure the resistance of my tongue while it's wet and ...
verarox's user avatar
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4 answers
836 views

I need to get a measurement from a variable resistor, ranging from 10-180 Ω. Measurement shall be better than 1% over a room temperature ranging from 5 to 45°C. This variable resistor is activated by ...
AutoPilot's user avatar
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I've been diligently working on designing a variable load for the purpose of testing both AC and DC power supplies. For this task, I have opted for the integration of back-to-back MOSFETs in the ...
Cinar Reis's user avatar
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3 answers
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I have an application where I need to provide a lower voltage from a starting voltage. In other words - I need a buck converter. My question is - if I have a known required differential but a ...
Daniel Miller's user avatar
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So basically, I want to store a pin of a PIC MCU inside of a variable. eg. int pin = LATB5 I also need to pass that pin to a function. If I do it like this, it ...
leo6002's user avatar
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I'm trying to design an automation for the status/current setting of my one electrical motor (1-6 variable settings) to drive a few behaviors to another motor or possibly two. The electronic devices ...
No-Reservations's user avatar
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1 vote
1 answer
414 views

I want to determine my minimum and maximum resistance rating for my variable resistor but failed to find the relevant information in the datasheet (this might be an issue more 'noobs' might have, ...
user2305193's user avatar
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3 votes
1 answer
295 views

I use an STM32 microcontroller board and to summarize the question, in the following code inside the if clause the variable called ...
user1245's user avatar
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2 answers
546 views

I have searched on google but I have not found a way to put different values in the variables of the same symbol placed more than once. Each component "X11, X12..." etc, are the same, and ...
Jose de la Rosa's user avatar
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2 answers
197 views

I'm trying to learn and in this case I have a power supply circuit that has a fixed 5V, a 1.25 to 12V and a -12V to -1.25. I understand that the regulators I'm using have a minimum limit output of 1....
wmorales76's user avatar
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1 vote
1 answer
670 views

I am looking for a way to create a variable resistance signal to mimic the signal that would typically be provided by a thermistor, but by using a digital signal that switches to ground. I currently ...
CSla's user avatar
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2 votes
3 answers
236 views

Is there elastic resistor material? I want to measure the respiratory rate and smoothness of each breath. And it would appear that a brute force solution to this problem could be a belt around the ...
user7858768's user avatar
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1 answer
146 views

I am a beginner, looking to make an extremely basic variable loudness (gain) audio amplifier. I have a general idea of how a class A amplifier works, but I am not sure how to make one variable. This ...
mihkelr's user avatar
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1 answer
78 views

I'm wondering if there is a way to store a small integer in a way that if you turn the microcontroller (an atmega328, in my case) off, and then turn it back on again, the variable won't reset. Do I ...
e3rowning's user avatar
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1 answer
160 views

I'm currently a senior ME major and just entered the EE world to complete project so I'm a little lost. I am building a circuit powered by an Arduino Mega Chip. The circuit is to control ...
Cuddisaveslives's user avatar
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2 votes
1 answer
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Is it possible to add a variable into the value of a component in LT spice? I'd like to simulate a resistor divider to look at current consumption but keep the ratio of the resistances the same. I ...
Pete's user avatar
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1 answer
374 views

We've purchased a bit old type of a power pack. It's got DC voltage manual reading bar and DC ampere manual reading bar. Assuming that it can measure the current while allowing to give a specific ...
AliceX's user avatar
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1 vote
2 answers
5k views

Say I have module_A , module_B and module_C and a variable as “reg[3:0] x”. I want all three modules A,B and C have access to read and modify variable x ( something like global variables ). Is it ...
Aug's user avatar
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810 views

I need to have variable resistor (from around 5kOhm to 100kOhm range). The problem is that this "resistor" see 350V (rectified 230V mains). The control signal is PWM and need to be isolated ...
eSlavko's user avatar
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0 votes
1 answer
596 views

I want to make a variable power supply up to 12V. For that I want to select resistor and adjust potentiometer values. I have calculated below values from this website.https://circuitdigest.com/...
usmandroid's user avatar
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-1 votes
1 answer
335 views

I am trying to switch on/off the connection between a load and a variable power supply (going from -10 to 10 V) using a combination of NMOSFETs and PMOSFETs. I want to use MOSFETs because of limited ...
Tungstein's user avatar
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0 votes
1 answer
85 views

I have a variable gain amplifier that can output a current of 90 mA. The output is directly connected to a µController I/O pin. My question is: do I need something like over-current protection, since ...
Yoomo's user avatar
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0 votes
1 answer
656 views

I'm building a clock/calendar with an ATmega, a DS1307, and a 20*4 LCD (LM044L). I have implemented the code showing the time correctly, I have initialized the RTC too, but for some reason when I try ...
Hitman2847's user avatar
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0 votes
1 answer
634 views

I have a fuel sender that works on 12V and sends the reading to the engine. The engine wont start with it disconnected (hence the diode). What I need is to copy the resistance of the fuel sender using ...
hughebeling's user avatar
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0 votes
1 answer
319 views

Total noob here, I'm looking to implement a circuit to control a fan that has these specifications: Pin 1 and 3 are DC- Pin 2 is DC+ Voltage should be from 6 to 16 V It needs to operate in 70-second ...
aelveon's user avatar
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0 votes
1 answer
107 views

I'm looking to have 4 dc-dc converters each with different outputs but one voltage input value. Vout of 9V 12V 15V and 18V. Would this chip be able to do that? Here is a bit from the data sheet and I ...
DRC's user avatar
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2 votes
4 answers
835 views

This is more a theoretical question: Let's say we use a potentiometer as a variable resistor. We can set it from 0% (0Ω) to 100% (let's say 1Ω for simplicity). Using this pot we can reduce the total ...
flawr's user avatar
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1 answer
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MCU: Atemga328P: Datasheet:https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-7810-Automotive-Microcontrollers-ATmega328P_Datasheet.pdf Note: I am a beginner :) Considering a 2 byte ...
user13174343's user avatar
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1 vote
1 answer
1k views

I've been wondering for quite some time how to create a sort of audio splitter. The idea is to get an audio signal (e.g. guitar) at the input, and have two separate outputs, one with the input's low ...
Piotr Sławęcki's user avatar
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0 votes
0 answers
404 views

I am using a hair dryer to increase oxygen/air levels in a torch assembly for a forge for metal work. I need to be able to increase/decrease the fan motor speed smoothly and more precisely than the ...
Ian G's user avatar
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1 vote
0 answers
840 views

I am making a variable DC power supply via Multisim and the values are given to me is V1=7, V2=15, Imax(load)=209mA (both V1 and V2 is DC value which is on U1.) I am using resistors, an LM317 voltage ...
Sabretooth 2438's user avatar
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