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.
3
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4answers
70 views
What is transimpedance?
I've googled almost 100 times, unable to find what really is transimpedance. Every search displayed results about transimpedance amplifier, but didn't tell about the term transimpedence.
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3answers
130 views
Is current able to flow through a Capacitor at DC?
Can someone clarify whether or not a capacitor blocks current at DC?
simulate this circuit – Schematic created using CircuitLab
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1answer
106 views
What could happen if I plug into my Arduino an AC adapter instead of a DC one?
I´ve read that Arduino needs a DC adapter and not an AC one, I know that.
What could happen if I plug into my arduino an AC adapter?
I need to do a quick test with two small 4.5v DC motors, and I ...
0
votes
1answer
71 views
How to make a proper DC Power + Battery circuit for audio effect pedals?
I'm building an audio effect pedal. I need to make a circuit that can either run from DC power or batteries. The key is to disconnect the battery if a DC plug is connected (by using a DC jack with a ...
1
vote
2answers
34 views
Varistor S10K30 for 24-40VDC input?
I was put in charge of redesigning a motor control circuit which accepts 24-40V DC on its input.
As a side note: As far as i know, the existing circuit has been working fine for several years. The ...
0
votes
1answer
60 views
Choosing Fuses or MCB in 24VDC vehicle circuit
I am currently designing a 24VDC circuit for a small vehicle. I personally prefer using MCB's since they are simple to reset and easy to detect faults in the system, although i do find it rather hard ...
3
votes
2answers
143 views
How to draw current from a telephone line?
My landline phone comes with a lcd display caller id and clock.
Even if I remove the 2 AA 1.5V batteries, the lcd still shows time even if I'm not busy on a call.
The lcd has no other source of power ...
1
vote
3answers
71 views
1.5V “amplified ear” debugging
I've tried to make this circuit, a 1.5V audio amplifier.
I've omitted P1 and directly connected C6 to C3 as stated in the page.
I've also omitted the switch SW1 and connected a wire for the path ...
0
votes
1answer
55 views
24VAC LED flood with 12VAC driver works on 12VDC—how?
I bought some cheap RGB flood lights from aliexpress.com. They were supposed to be DC24V (I intend to run them off a solar/battery setup) but I ended up with AC24V instead. What clued me in was the ...
3
votes
4answers
109 views
Current flow with two voltage sources
Consider this schematic:
Light 1 has 1.5V across it while Light 2 has 3V across it.
I was explaining to a friend how the points (indicated by Loop 1 and Loop 2) could both be used as a reference ...
1
vote
3answers
174 views
Why is a railway's third line or overhead line DC and not AC?
As the title states, in the rail industry, why are the majority of railway's third line or overhead line in DC volts and not AC volts? My initial guess would be that it is in AC since it is easier to ...
0
votes
0answers
43 views
Maverick probe causes ardiuno to reset when touches grounded electrical item
I have a Maverick 732 probe connected to an Arduino for measuring temperature. The outer shield of the probe is connected to the ground pin on the Arduino, and the other wire is connected to an analog ...
1
vote
1answer
86 views
clean 12v car power
I am looking to get a constant, clean 12v from my cars 12v line. I am wondering if all I am in need of to pull this off would be a simple 12v fixed regulator?
The 12v would be hooked up to a pico ...
0
votes
0answers
50 views
What is the best way to run fluorescent lights on DC power?
Using two 6 volt alkaline batteries, (4) 6 watt 8" fluorescent T5 tubes, and wanting to be able to turn the lamps on and off frequently without ruining them, what is needed and what would be the best ...
0
votes
0answers
46 views
0-5V 1A Dual Output DC Power Supply - SOFTWARE CONTROLLED
I am interested in purchasing (or building but preferably purchase) a software controlled DC power supply. Preferably, would like to control the output using LabVIEW.
I need two separate outputs ...
-2
votes
2answers
71 views
DC Adapter on AC Adapter Speaker [closed]
i've Speaker with woofer requiring AC 12 voltage, and i have DC 12 voltage Adapter.
However, speakers are working properly.
but Can i use DC 12 V Adapther with the Speaker which is requiring AC 12 ...
0
votes
3answers
298 views
Does converting 12V DC to 110V AC really increase the available watts?
When designing solar panel systems for homes how do you convert the watts generated by the 12V DC solar panels to watts available in a 110/120V AC system? When I do the math it seems to defy logic.
...
-4
votes
1answer
73 views
Why Do Y Electrial DC Fuses Burn Out? [closed]
I am doing some re-search for my father that works with electricity. He say that his Y Dc Electrical Fuses start to burn out, a lot. Please Help. xx
10
votes
5answers
891 views
Why don't more devices incorporate full-wave rectifiers as reverse polarity protection?
Recently, I was introduced to the idea of using a full-wave rectifier, in order to protect against reverse polarity damage in DC devices.
I hadn't even considered using a rectifier in an already DC ...
0
votes
2answers
46 views
Nodal Analysis of a Circuit
I'm trying to apply Nodal Analysis here.I have found that taking reference Nodes and application of Kirchhoff's laws yields some equations and on solving these equations i will get the needed ...
1
vote
1answer
84 views
DC 5V to 3.3V DC-DC Step-Down issue
TL;DR : The output voltage from my 5V DC to 3.3V DC stepdown seems to output 4.5V DC - why?
Background:
I'm trying to power an Airport Express from USB rather than a wall outlet. I have discovered ...
2
votes
4answers
118 views
Superposition theorem
I'm trying to apply the superposition theorem.
I'm confused how the value of \$I_2\$ is calculated, from where does the value of 1 come?
2
votes
3answers
106 views
DC Motor Efficiency at Fixed Torque
I am in a muddle here, so thanks for making the effort to have a read.
I understand that electrical power going into motor is given by:
\$P_e=I^2R\$
I understand that mechanical power out is given ...
1
vote
1answer
44 views
Off-grid Solar with DC Backup
I would like advice on a potential new set up I am looking at installing in my home.
I have a small water heating system that runs @ 150w 24v DC, I intend to use the solar to power the heating system ...
2
votes
2answers
184 views
DC/DC Converter minimum load?
I'm using the NTE0506MC DC/DC converter which boosts 5V to 6V. The output voltage I'm measuring with no load is 9V not 6V. In page 3 of the datasheet they mention that it needs a minimum load of 10% ...
4
votes
4answers
88 views
What are the factors that significantly affect the life span of a DC motor?
I'm currently planning to run a DC motor continuously on solar power. So I would like to know which things I should be very careful about for optimum lifespan of the motor. I found the following two, ...
1
vote
1answer
84 views
AC DC Analysis of diode
in the following circuit:
Im looking to find what \$v_D(t)\$ is given \$V_γ = 0.7 V\$ and \$r_f = 0\$.
Now when doing the DC analysis, find that \$VDQ = 0.7 V.\$
But im having trouble finding ...
0
votes
0answers
69 views
Choosing the correct brake resistor for DC motor
I have a DC motor running on 24VDC rated 150W (~6,25A), how do I calculate the correct brake resistance?
1
vote
0answers
57 views
SEM Permanent Magnet DC Motor DPM 30R4 1500RPM 24VDC Output: 0-25kW & Brake
I am in the plannning stages of a project to build a pig rotiessiere. I have the above mentioned motor, but I am unsure of what type of power source is needed to run the motor and what can I do to ...
0
votes
1answer
68 views
Frequency of fluctuations in power in an input power design circuit
I am thinking about the following power design circuit in section 6.1 : http://www.arndaleboard.org/wiki/downloads/supports/BaseBoard_Specification_Arndale_Ver1_0.pdf
Is it possible to calculate how ...
1
vote
2answers
138 views
Providing DC power with failover DIY for IP camera
I'm building a simple battery backup box for a 5V IP camera. I've got a few options for battery, sealed lead battery or a mix of portable LIPO style "USB" power bricks. I've seen boards built for ...
0
votes
2answers
106 views
Battery powering an unknown DC motor
I know nothing about motors. I have DC motor (sealed in a casing) that uses 6v/12v 1a (mains switching power supply) with 2.1x5.5mm DC connector. It has variable speed controller, reversible ...
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votes
1answer
71 views
How much current draw will a dc-dc converter have in this situation?
I am trying to make a mobile computer for my Raspberry Pi. The problem here, is powering the Pi, screen AND the USB hub from the same power source. I have bought this: ...
0
votes
1answer
72 views
1-pole and 2-pole DC circuit breaker
My question is rather simple, when and why do one use a 1-pole or 2-pole circuit breaker in DC (+24VDC and GND)?
-1
votes
1answer
86 views
Will a 40W incandescent AC bulb operate on a 330V DC voltage?
Will a 40W incandescent AC bulb operate on a 330V DC voltage or not?
0
votes
0answers
45 views
Loading effect problem
i m trying to connect a de sauty's bridge(AC bridge) output to a precision rectifier. The problem is the output of the bridge (AC bridge) changes drastically to 5volts as soon as the connection is ...
2
votes
1answer
141 views
How to build “two power sources” in a microcontroller circuit?
My circuit has a microcontroller, it uses power from a DC transformer (120V to 12V DC). My circuit also control an pneumatic valve which also use 12V DC. Almost every time when the pneumatic valve ...
0
votes
0answers
46 views
DC circuit breakers in automation plant
I am currently working on designing the power grid of a automation plant. Since i already have a background in automation, the rule of thumb i usually follow is to have circuit breakers in front of ...
0
votes
1answer
52 views
Frequency and magnitude of power variations in a DC circuit.
I have a 5 V 5 A power source which is connected to a simple development board with a processor that draw current dependent on utilization. I use a multimeter that measure 1000 samples / s to measure ...
1
vote
1answer
94 views
Electrical saftey of metal panel-mount DC jacks
Context:
I have a robotic arm with a series of servo motors, that together draw up to 3A from my bench supply (depending on the load on the servos). To make it easier to transport the robot around, ...
2
votes
3answers
122 views
Can supplying DC power into an AC device break the device?
I have an AC device that takes 12 volts 47-63Hz AC. It is a water softner that is essentially an electromagnet. I lost the original plug and supplied it with 11.2V DC, it came on for a few minutes and ...
0
votes
1answer
84 views
I think I am looking for a specific DC relay switch
I am looking for a switch not sure what kind though.
let me explain:
I have two sources one creating DC 12v, second one creating around 6v DC.
One source works for about 12 hours each day then ...
5
votes
3answers
234 views
Why are the power transmission/distribution systems AC and not DC?
Is there a good reason why we are not in the process of completely converting our electrical transmission system to DC? The main reason for using AC on the grid (no offense Tesla, I love you man) was ...
4
votes
1answer
85 views
2 full bridge with 2 secondary winding in series… is it possible?
simulate this circuit – Schematic created using CircuitLab
Is this possible? Think of the center tap transformer as a 2 winding connected in series
1
vote
3answers
150 views
How is current lowered as Voltage is increased in AC power transmission
I was reading about power transmission on wikipedia and came across the explanation of the efficiency of AC power transmission that said power in the load = (I^2)* R while power transmitted= IV. The ...
1
vote
1answer
65 views
Which electro motor to use for steering a kite? (guestimation marathon)
I'm doing a pet project in which I want to fly a kite from my computer. For this to happen my plan is to build a little box hanging under the kite which includes a raspberry pi (connected to my laptop ...
2
votes
1answer
205 views
Mixing AC and DC power in a circuit
This is likely a noob question, apologies if the answer is obvious.
I'm trying to control a furnace using a 3.3V microcontroller. The furnace operates by connecting a common 21V AC "hot" line to one ...
1
vote
2answers
97 views
DC Voltage Grounded with AC Input
This is an image from a book showing us how to solve BJT circuits via AC analysis:
So I understand that when doing AC analysis to ground all the DC voltage sources but I don't understand why. Can ...
5
votes
2answers
186 views
Should I use multiple voltage regulators?
I have five devices that need to be powered. I would like to use one DC source to power the four devices. Should I use voltage dividers, voltage regulators or a mixture of both? Also, any ...
2
votes
3answers
130 views
DC-DC isolation for my car stereo… Where do I start?
I recently noticed that my jeep's stereo whines with a frequency that seems proportional to the rpm of my engine (and alternator), and is louder when my headlights are on.
If my stereo was powered ...
