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Questions tagged [dc]

DC stands for Direct Current, which means the flow of electric charge in a single direction. Examples of a DC source are batteries, solar panels, dynamos.

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Fan voltage fluctuating with potentiometer [duplicate]

I am driving a two side by side fans (original Xbox 360) from 20v, 4A source via a 12v regulator and a 10k trim potentiometer. The goal is simply to adjust voltage between 3v-12v, nothing I havent ...
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1answer
46 views

Clarification of an answer about CT sensors and diagram

Hi I have found a perfect answer that clears the purpose of the parts in the schematic. So two resistors and arduino 5v source adds up to the negative side of the AC voltage. Is there any "special" ...
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83 views

Powering Motors in War Robot

I would like to give you all some premise before asking this question. I am a highschool student from India and I generally do software development, so this is one of my first hardware related ...
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2answers
126 views

Hack for connecting two terminal blocks?

If I bought some of these connectors. Is there an easy way to connect two of the green terminal blocks together? i.e. I would end up with a male to male DC adaptor. Could I do this without having ...
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0answers
49 views

Using a “fake” battery as adapter to allow the easy usage of an external DC PSU

I think everyone has gotten to this problem already, you have a device that you want to us as fixed installation but it only has a battery compartment and no socket. So the only thing you can actually ...
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0answers
30 views

Isolation of circuitry from heat source

I'm building an electrolysis unit which will comprise a refractory crucible, containing the electrolyte and the electrodes. The heat will be generated from a furnace to aid the desired reaction. A ...
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2answers
74 views

Question about modem (analog/digital)

As I have understood the concept of modems, modems translate digital signal to analog ones and in reverse. Well and then I've read the definition of a modem (technical book): A modem converts ...
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2answers
153 views

DC voltage ripple help

I am new here and I realy need your help. For diplome at the end of my studying I am making the audio amplifier module (power amplifier, preamplifier, tone control, power supply, linear regulator) all ...
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1answer
64 views

Braided or stranded tinned copper for flexible connection?

I need a series connection between sets of batteries dealing with around 120A at 52V peak in an electric longboard. I expect the highest flex will be around 45 degrees, but mostly less than 20. I ...
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0answers
30 views

Limiting current flow from vehicle DC out to house batteries

Looking to hook up 4 Battle Born 10012 100Ah LiFePO4 batteries in parallel in a Ford Transit van. The Transit has the Ford Programmable Battery Guard option. This option provides a DC terminal that ...
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0answers
31 views

DC to DC boost current problem

I am attempting to boost a DC power source (from either 12V20A PSU, 12V 120W car cig port or 14.8V 10aH Lipo) to 26.1V and 6.9A (or 4.5A) using the car cig port taking power limit into account. I am ...
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1answer
154 views

Questions about Tesla coil (SGTC), spark gap and resonance

If I use a step up transformer (flyback for example) for primary to boost the voltage to 10 kV which (flyback) has a resonant frequency around 30-50 kHz, and the primary coil has a res. freq. of 500 ...
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1answer
52 views

Total capacitance of two sets of parallel capacitors and resistors in series.

Assuming C1 and C2 both are rated at 2.5V. Is the total capacitance of C1 and C2 0.5uF or 1uF? simulate this circuit – Schematic created using CircuitLab
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41 views

AC sources in DC analysis

Can I ground AC voltage sources when I do DC analysis of differential amplifier with BJT and current mirrors circuits?
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1answer
70 views

How to use 24V 100Ah battery to run 12V motors?

How can I run 12V motors with the current of 30A together with 24V 100Ah battery? Should I modified my circuit to change 24V to 12V and connect to motors? or Should I find a battery which can change ...
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1answer
579 views

Does polarity matter for a DC rechargable battery?

I have a handheld wireless rechargable mini-vac (like a Dustbuster). The charger outputs 19V DC 150mA. My cat chewed through both wires on the adaptor. Both wires are completely black with nothing to ...
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1answer
137 views

Why DC block is used for GPS receiver tested using a simulator via an active antenna?

Reading up GPS testing using a simulator and came across several articles which suggest requiring a DC block capacitor in the RF path between the GPS Simulator+Attenuators & Active Antenna. Some ...
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1answer
47 views

Arduino reading double-din radio volume rotary dial knob [closed]

Hey all I bought a Chinese double din radio in order to modify it to my liking. The main reason why i went with this one is that it had a few buttons and turn knobs on the front and i wanted to use an ...
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1answer
196 views

1.5v solar cell to replace two D batteries

I just bought a very small aerator called "Metal Marine Bubble Box" that runs off a small DC motor. Not much torque needed. I tried reading the print on it and all I could read was 1.5v. This makes ...
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1answer
25 views

Type of power converter to be used for both AC and DC use

What kind of power adapter that I need to use to supply power for a DC motor of a fan and also an AC heating element? These two components will also connect with Arduino. Is any of these power ...
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1answer
58 views

Calculating the 12V battery requirement for a 240V invertere system

I plan on powering a 240VAC mobile candy floss making machine from a 12VDC leisure battery using an inverter... the problem is my understanding in this area is rudimentary. Candy Floss (cotton candy) ...
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2answers
49 views

Fuse Protection inline with DC Brush Motor

I have run into a number of instances where my 12A DC brush motor (linear actuator) is being overloaded. I have tried fusing it with a 10A Blade Fuse as well as a 15A Blade Fuse. In both instances, ...
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2answers
90 views

How to convert 85 Volts DC to 5 Volts DC

I have a LED driver which model is HC(8-18)X1W Output: 300mA and it gives 85 Volts output. I want 2 outputs from it, as parallel 1- Same 2- 5 volts Amazon specs Output : Constant current 300mA 72~...
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1answer
53 views

12VAC Common Reference

Working on a design where power supply (on the PCB) is 12VAC to full wave rectifier to 5VDC linear regulator. Customer switch box is also power via same 12VAC source and will be switching that 12VAC ...
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2answers
202 views

Why does this single supply non inverting Op-Amp saturate?

I have this simple non inverting setup made with a TL082IP Op-Amp and a gain set to 2 (R1 = R2). Since I will only have positive voltage 0V to 5V to amplify, I use for simplicity a single 12V/0V ...
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1answer
58 views

Battery to AC conversion voltage question

I am converting a device that uses 2 [C] size batteries (1.5V) to use a transformer in an AC outlet. I understand that the transformer rating should output 3 volts. However.... I only found a 3.2 ...
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1answer
59 views

Small wind generator project

Why when I spin a dc motor (USED AS A GENERATOR )with drill it does not light up led , but when I spin it with my fingers it light up
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3answers
112 views

Protect a micro controller even on mistakenly connected

I am basically a computer engineer and having only basics in electronics and electrical field. I have also searched for the solution but it looks, it would be better if i ask it to experts here... ...
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7answers
2k views

Is there any difference between transferring DC over one 36 mm² wire or six 6 mm² wires?

I am designing an off-grid DIY solar power site where the distance between the solar panels and inverter is going to be several dozen meters, so I would prefer to put a thicker wire to minimize losses....
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1answer
72 views

DC Motor Theory and Practice

My first post here, I have been playing with a DC motor and attempting to upgrade the original batteries from SLA to Lipo, the scenario is as below and i'm looking for some advice on what happened and ...
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0answers
58 views

DC disconnector/breaker and battery fuses for 24V 100Ah solar system

I have an off-grid solar system up and running well so far. However, as far as understand there is one essential part is missing in the setup which is the DC disconnector between the inverter and the ...
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1answer
515 views

What is a load current?

I was trying to calculate the voltage drop of a copper wire due to its length, given that it has a fixed size and it transmits DC current. Anyway when trying to calculate it with one of this online-...
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2answers
67 views

What happens if I use a DC adapter with a15v output with a PC monitor with a 14v rating?

I have a PC monitor with a 14v rating but it's original DC adapter is broken. Can I safely use a similar DC adapter from a similar monitor, but with 15v output instead? How likely is the 14v monitor ...
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38 views

Understanding and finding this DC-DC converter

Reading a circuit, I found the following component: Which is a simple DC-DC converter. There is no possibility to find a datasheet for it. My two questions are: I understand that VO1 is supposed to ...
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1answer
50 views

How do I use an LEDs wired for 277V AC on a 12V DC power supply?

I have some LEDs that I am trying to re-purpose. They were originally running on 277V AC. The LEDS are soldiered onto a pretty large board with just two wires coming out. If I measure the ...
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2answers
209 views

High Current DC LEDS Strips with Aluminium Plate… is grounding advisable?

I'm in the process of planing to make a rather large LED light panel that uses 24v 130w in total. The LED PSU Driver is rated up to 150w and comes with 3 inputs (earth, neutral and live) and 2 outputs ...
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2answers
392 views

How to convert 12V 3A Car battery to 5V 1A? [closed]

I want to build a GPS tracker for car for which I need a 5V 1A to power my circuit. The power source being Car battery of 12V 3A, what should I use to get my desired voltage and current? There will ...
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6answers
2k views

Are there any true direct-current motors?

The "DC motors" that I'm aware of use a DC power source, but they have a current running through a coil that changes direction based on the angle of the motor. Therefore, they current inside actually ...
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2answers
90 views

RLC without Source, finding the value of Resistance given I(0)

A capacitor of 1.58mF was charged by a battery of 12V and lies on the ground of an abandoned radio station. During a storm, an old telephone cable fell from a rack and one of its tip got in touch with ...
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0answers
42 views

Partition of state space in 2-dimensional Euclidean space

I'm working on creating a state space model with DC-OPF solutions. I have a 3-bus system and hence, a 2-dimensional state space. Under DC-OPF the states are voltage phase angles. I'd like to model a ...
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2answers
52 views

How to connect Dc motor to Diode transistor logic

So I have a nand gate using DTL (diode transistor Logic) but i don't know how to connect my DC motor to nand gate logic , I tried to put my DC motor to the output of DTL but it isn't working, may you ...
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1answer
26 views

AC adaptor needed to power multiple devices

Basically working on a project, still in the conceptualizing stage, where I need to output power to 3 devices, 12v 2A, 12v 2A and 5v 2A, ideally off one ac adapter. I was thinking of using a dc to dc ...
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2answers
116 views

need info about dc-dc boost converter [closed]

I purchased a "1200W DC-DC Boost Converter Power Supply 8-60V 12V Step up to 12-83V 20A 24V 48V" off eBay. My applications are for charging a DIY 48v e-bike battery I assembled from 78 individual ...
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4answers
101 views

Where does energy go when not enough voltage is applied to charge a battery?

Currently I am working on creating a DC motor that when manually cranked, or spun, will charge a rechargeable battery. Through some research I found the only way to charge a rechargeable battery is by ...
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1answer
54 views

How to determin the load requirement for 24V DC power supply

I'm working in automotive industry, I got a project to add extra hardware to particular line. hardware actually requires 24v 70w. Now, we have a Power supply unit "power one he-24V-7.2a" in the ...
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0answers
46 views

connecting multiple rails of a single dc power supply in parallel

I have a meanwell 24v 10A(Max 14.2A) DC power supply unit having 3 V+ and V- outputs each, i.e a total of 9 outputs including L, N and Gnd. I will be using the unit to power an EC BLDC motor(https://...
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3answers
463 views

Why Does DC Load Draw Twice As Much AC Current Through Transformer?

I have designed the following circuit, comprised of 4 loads, 1 of 4.2ohms and 3 of 21ohms, drawing a total of 2.4Arms (1.5A, 300mA, 300mA and 300mA respectively) of AC current through the secondary of ...
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1answer
42 views

Inductor in DC circuits and DC/DC converters

Quick question which is somewhat confusing me. So I understand that an inductor will have no effect in a DC circuit and merely acts as a resistor, as no change in current will be seen. However for ...
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82 views

What does a multimeter read when you measure unstable DC-voltage [duplicate]

When I have a Fluke True-RMS multimeter. Does the meter measure DC-RMS voltage or the average voltage?
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3answers
119 views

VARIAC as DC motor speed controller from DC power source

I'm not sure if this is is where I should ask this but is it possible to use the VARIAC as a DC motor controller from a DC battery source? The thing goes like this: The 48V, 3kW DC motor is connected ...