Questions tagged [basic]

Fundamentals of electricity, electronics, components, or theory

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2answers
54 views

Am I overthinking this simple power supply connection?

I want to connect a 12V fan and a motorcontroller to this generic ac to 12v dc power supply. The motorcontroller is pulling around 25 amps, and the fan about 1. I'm just wondering, should i add a ...
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2answers
121 views

How to find current through inductor when connected in series with an ideal diode?

Please help me with this simple circuit, which is creating lots of confusion due to different results from theoretical calculation and SPICE simulation. Ques: In this circuit switch is closed for time ...
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3answers
79 views

Resistors in series to increase maximum Voltage

Do the values of resistors matter when I want to use them in series to increase the maximum voltage they can handle? So can I just use a 1 megohm resistor for example that's rated for 200 V and then ...
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1answer
79 views

Controlling a motorized ball valve and appliance with a float switch(es)

I am trying to create some redundancies for a small commercial ice maker to prevent there from ever being a flood in my garage. The ice melts from the ice bin (which holds around 80lbs of ice) ...
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1answer
136 views

Undervoltage lockout

I would like to do a simple undervolatge lockout. I thought a BJT as a switch like this: In normal conditions I would have 30V (and -30 and the othre rail) and 25 mA to 50 mA. These power rails will ...
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1answer
47 views

Power Supply stopped working after soldering

I am new to electronic circuits. I built a basic led circuit on a breadboard to test everything out.It worked as in pictures,but the connections were not stable because the holes were very large.I ...
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2answers
131 views

How to get negative voltage?

There's a bunch of posts about this, but they're all for very specific scenarios. I'm a newbit, and some components, like op amps, require both a positive, and negative voltage. But how do you get ...
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3answers
87 views

Why is the resistance of parallel circuits lower than either of the individual parts

I am watching this tutorial, and topic of parallel circuits came up. In the below image, the combined resistance is 60Ω, which is less than either of its parts (150Ω and 100Ω). I understand how the ...
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3answers
130 views

Voltage of capacitors after long time (RC Circuit)

I'm currently taking a course in electromagnetism, and I got stuck with this problem: The Problem: All of the resistors and capacitors have the same values, R and C respectively. The circuit is ...
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2answers
72 views

I'm trying to make a clock pulse generator but when I run the simulation nothing happens

I am new to using circuit/breadboard simulation apps. When I run the simulation nothings happens. Here is the original schematic. Edit: I'm using 74HC00. Also I learned how to use Virtual Breadboard ...
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1answer
87 views

Why can't KVL be applied here?

I was asked to find the Is current I applied KVL in that loop but my ans is wrong. what concept is wrong on my approach?Why kvl cant be applied on that loop please explain
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2answers
82 views

ADC is giving fault codes when I touch thermistor attached to it

I am working on writing a control program for my pellet smoker. I am having an issue with the meat thermometer that came with the smoker. I have a MAXIM 31865 ADC that is connected to a Raspberry Pi. ...
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4answers
115 views

How to modify the supply voltage requirement in a circuit?

I am a beginner in Electronics; I am learning the basics and am trying to take up circuitry as a hobby! My query is regarding power supply requirement for any circuit. Take, for example, a circuit to ...
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1answer
42 views

Thermal circuit for shared heatsink

I am following this video from EEV blog where he talks about calculating heatsinks and I noticed that he does not talk about multiple components sharing a single heatsink. I have lurked around the ...
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2answers
51 views

low-cost transmitter and receiver, no MCU involved hopefully

a newbie on electronics here. I would like to create a simple RF kit. on transmitter side, only 1 button. on receiver side, if a valid code is received, a relay activates to provide 12VDC to a load. i ...
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1answer
52 views

Would a DPDT switch work to turn either one or both devices in this circuit?

I'm doing a replication of vehicle hi/low beam switch in my "lab" and I'm not sure what's the right type of switch for it. It has to have a dedicated on/off switch (the one on the bench ...
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3answers
76 views

How to lower wattage of circuit

I want to power a computer fan from a 12v motorcycle battery. Disregarding the motorcycle battery being 12.6 volts (not charging), lets say that it's a regulated constant voltage source of 12 volts. ...
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0answers
33 views

What is nominal SNR in Massive MIMO?

I have read a couple papers that mention nominal SNR in Massive MIMO. In the places where I have seen it, it says it is the SNR of the User when M = K = 1. This means that it is the SNR when the the ...
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2answers
291 views

Working of bipolar junction transistor with electron flow

I faced a lot of problems in understanding BJT. I am going to share what works for me. Suppose we take an NPN as the transistor in our case. The emitter base region is forward biased, so electrons ...
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2answers
77 views

On off switch with 2xLED

I'm trying to connect an old/possibly broken switch to a light from a 12V battery (very good first question isn't it?). The switch is meant to light Green when ON mode and Red in OFF mode. The schema (...
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2answers
51 views

Why is my voltmeter output incorrect

So I'm completely new to electrical design. I thought I'd try out the most basic experiment I could think of. Here I hooked up two AA batteries to a breadboard along with a 10 K resistor. When I ...
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2answers
113 views

Will Kirchoff's voltage law work in a vacuum

Kirchoff's voltage rule tells us that the sum of voltages around a closed loop in a circuit will equal zero. If a battery sits on a table, using KVL and treating air as matter with high resistance ...
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1answer
32 views

resistor combination circuit

simulate this circuit – Schematic created using CircuitLab This is probably a very stupid question. I am new to electrical engineering in general, I was working with NOT transistor gates in ...
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1answer
50 views

Multisim Multimeter showing blank reading (--------)

I am trying to build a simple circuit to back up some hand calculations that I am completing for a project. However I am unable to get a reading on the Multisim multimeter. I have changed the ...
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3answers
157 views

Why does the impedance of a parallel RLC circuit approach infinity at resonance?

Pretty new to this stuff so apologies if I get some words wrong. In the book I'm reading they described a parallel circuit with a resistor capacitor and an inductor powered by a current source. They ...
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2answers
118 views

Why does pin numbering and placement (in general) appears to be done so haphazardly to the uninformed person (me)?

Be it an ESP development board, an IC controller, even an LED segment number itself, pin placement never seems to follow a logic when it comes to actual numbering, or function. I can't find a simple ...
3
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1answer
138 views

Filter w/ seemingly higher output voltage than input?

I'm working on a simple LC filter as part of an AM radio project. I was intending to use a ferrite antenna (modeled roughly by the voltage source in series w/ inductor which is then connected to a ...
6
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4answers
330 views

Simple power on delay for 3.4v-5v serial device being powered by 5volt VCC

What I am trying to do I am trying to build the most simple as possible circuit to give a 3.4v-5v serial device a 1-2 second power on delay from the embedded Linux device running at 5v that it is ...
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4answers
180 views

What is the relationship between electrical resistance and heat generation? [duplicate]

An incandescent light bulb has some amount of resistance (let's say 30 ohms) and generates a large amount of heat. It's my understanding that a resistor with the same amount of resistance (30 ohms) ...
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1answer
59 views

I want to understand this audio input to LED output simple circuit

I'm a newbie in electronics. I watched a youtube video that showed how to activate LEDs using a microphone. It's project #3 at https://youtu.be/zsJ61yJhWVU?t=115 The guy built the circuit on camera ...
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1answer
121 views

How do I ground my power supply?

I have a Meanwell GST120A24-P1M +24V power supply (picture below). I want it to power a circuit of mine. Say the circuit is as shown below: one power supply and one resistor. How do I connect the ...
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0answers
49 views

Noob Question, 74HC240 and Solar Cells

My idea is to start soldering and I would start with something quite simple. I chose the project (https://cdn.makezine.com/make/08/pummer.pdf), a pummer with solar cell charging up a supercapacitor ...
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4answers
1k views

How do I determine whether a switch can handle the power/current in a circuit?

I have a switch that has "3A 250VAC" and "5A 125VAC" printed on it, which I imagine are ratings of what the switch can handle, but my understanding that 3A at 250V would be 750W ...
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2answers
47 views

Basic Series/Parallel connection understanding

I am just starting out with electronics and I have understood that there is something fundemental I just cant seem to figure out about parallel and series connections. I am having a lot of trouble ...
3
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1answer
96 views

Is it safe to cut these wires?

My kid got a face mask with flashing eyes, but there's also some annoying sounds that comes with it. Is it totally safe to cut the white wires or could the awesome flashing lights stop working too (...
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1answer
114 views

Circuit with 1 diode in parallel with a resistor

Sorry if this question has been answered here before, but I just can't seem to find any info on this. A little background. I am currently doing an automotive mechatronics course and, while I know some ...
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5answers
270 views

Basic BJT current mirror : … so the collector-base voltage of Q2 is also zero?

From this schema I don't understand this sentence from here, particulary in section "Basic BJT current mirror" "...If Q1 and Q2 are matched, that is, have substantially the same device ...
2
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2answers
71 views

Please help me with finding if I need to add a resistor to my circuit

I want to connect 3 4V LED strips in series to a 12V, 1A supply. Each strip requires 250mA current to operate. This makes a total of 750mA required current for all 3 strips. My concern is how should I ...
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1answer
63 views

Resistor across output?

I'm trying to learn about gates.Why is a resistor connected parallel across the output?
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2answers
206 views

RC Low Pass filter, capacitor in series or in parallel?

I've seen 2 variations of the RC low pass filter, sometimes with both the resistor and capacitor in series, and more commonly with the capacitor going straight to ground. What is the difference ...
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2answers
177 views

Reverse biased diode

What would be the voltmeter reading in the following circuit?
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3answers
234 views

Why does the voltage drop across an LED matter when determining an appropriate resistor value?

In determining the voltage dropping resistor, why is the forward voltage of an LED deducted from the supply voltage instead of considering the supply voltage alone?
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1answer
1k views

Wiring RGB Strip LEDs w/ just positive and negative wire [closed]

I'm working on a small project, and I had some leftover strip LEDs lying around. They're just the RGB strip LEDs you can pick up at Five Below. They come with an RGB controller attached to a short USB ...
0
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1answer
95 views

steady state voltage in capacitor network

simulate this circuit – Schematic created using CircuitLab I have this capacitance network in my circuit and I can't figure out the math behind why the final steady-state value of Vx=0.542v when ...
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2answers
53 views

Resonant frequency and maximum signal width

I've seen resonant frequency being defined as the point where the input signal is in phase with the output signal (So reactance/susceptance is 0). However conceptually, teaching material seems to link ...
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0answers
90 views

Audio amplifier circuit explanation

Recently, I am working with amplifier circuits but circuits available online for an op-amp have some extra components with respect to what we learn in textbooks. I know the basic amplifier components ...
3
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1answer
110 views

Current Divider with dependent source

I'm currently studying electronics for the first time. The objetive of this exercise is to calculate the current I and the dissipated power in the dependent source. However, I'm having a hard time ...
0
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1answer
45 views

Trigger two circuits with single SPST switch

I'm an electronics noob willing to learn. So I have a door bell that looks like it is wired like this: And I've bought a fancy 3V battery powered device that is intended to be wired simply like this:...
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2answers
107 views

How to get started with learning electronics? [duplicate]

My main goal is to be skilled enough to design printed circuit boards to build devices like a basic smart watch and other simple projects. How do I get started ?
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2answers
191 views

Output characteristics of transistor

Why is the slope of output characteristics of transistor in CE configuration more than that of CB configuration??

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