Voltage, otherwise known as electrical potential difference (denoted ∆V and measured in volts) is the difference in electric potential between two points (adapted from Wikipedia). Voltage can be constant (DC) or varying (AC).

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Secondary voltage with parallel, mismatched transformers

The thought came into my head, what if you had 2 transformers say they're both line level primaries and the secondaries are 6V @ 1A and 12V @ 1A. If you connect the secondaries in parallel, what is ...
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2answers
59 views

How to convert the Voltage source into a Current source

I'm confused about how to convert the voltage source into a current source so that I can derive a NAM equation. I've looked around for help but most of it tended to be of simple examples where the ...
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0answers
30 views

laptop power characteristics and new power supply [on hold]

I have a laptop Toshiba Satellite Z930 with DC 19V @ 2.37A power characteristics. Also I have a wall laptop power charger Kensington with USB power port: ...
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1answer
64 views

How to figure total voltage with two voltage sources in the circuit [duplicate]

I have some questions about multiple voltage sources while figuring out KVL. Ive included a circuit labs circuit which shows my question more clearly. ...
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3answers
96 views

Peak and RMS voltage for a sine wave

I only need help with part C). What I've done for part B) is square the wave, which makes Vpeak->V^2peak and the waveform in the negative region(under the period axis) become positive AND ...
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1answer
60 views

Understanding AC to DC conversion

I am able to see following specs on my laptop adaptor. 65 W Input AC: 100 - 240 V, ~1.5 A, 50 - 60 Hz Output DC: 19.5 V, 3.34 A My HP laptop: I am bit unclear ...
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2answers
72 views

Making a “voltage switch”

I'm an electronics newbie. I have a circuit in which I have two input voltages, Vin and Vflag, and one output, Vout. Basically I want the following: If Vflag =0, Vout =0. If Vflag = 1, Vout = Vin. My ...
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55 views

How can a DC-DC converter kill SLA battery voltage on light load?

I'm running a small 12V-500V DC-DC converter (shown) on a purely resistive 50mA load. I was getting weird behavior off my bench 12V DC supply so I plugged in the SLA battery shown. I connected a ...
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2answers
64 views

12-bit output to +/- 10v

Suppose we have a signed 12-bit output which is capable of representing both positive and negative numbers, how can this be converted to a +/- 10v signal using DACs, op-amps, etc. For example, 1100 ...
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2answers
83 views

How does Current relate to Voltage in their behavior in our physical world [duplicate]

I'm really an electrical noob who tries to understand voltage, current and resistance. I know the formulas and can somehow come up with basic explanations about the physics of electricity. However, ...
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1answer
54 views

What device to lower voltage for measuring purposes [on hold]

What device would I need to take my 120V power at home and drop it several volts so I can test why a laptop, a printer and a camera I work with do not function? The problem manifesting is the laptop ...
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1answer
54 views

Designing an High Amperage, Low Voltage AC Voltage “Breaker” for Model Train

I’m trying to build a simple circuit that acts as a "voltage breaker" – meaning that if a voltage exceeds a certain threshold, analogous to a (current) circuit breaker it will open a circuit. There ...
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4answers
108 views

Methods for converting PWM to +/- 10v Signal

Suppose we have a PWM signal which controls the speed of a motor and a digital pin which specifies which direction a motor is travelling in, how can we convert these signals into 1 +/- 10V signal ...
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3answers
239 views

If negative input ==> 0 V Otherwise, input voltage

I am struggling, and I would like to know how I can make a circuit that holds the following conditions: If the input voltage is negative, then the output should be zero volts. If the input voltage ...
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1answer
40 views

Wire for speaker design [on hold]

What is the power capacity of 30AWG wire used for speaker with 8ohm resistance. I tried using 15W amplifier and blown up my speakers. Without having used the amplifier no sound is produced.
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3answers
50 views

TPS54231 input voltage sensitivity quite high?

I've spent this evening blowing up TPS54231s. Even a couple of TPS54331s. (note that C31 is currently DNP) The input voltage is specified as 17-24 VDC, and this circuit's worked admirably well at ...
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2answers
63 views

3.3V input to 5V output for motor control

I wanted to connect my DC motor to raspberry PI and control it with PWM pin. Problem is that gpio pins are 3.3V in PI and I have pololu 10:1 DC motor which I would like to run on 5V(to make it ...
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2answers
74 views

what is the maximum output voltage from an opamp in general case?

In general, what is the output voltage that an amplifier (not rail-to-rail output type) can provide,if it is supplied for example Vdd=+24V and Vee=-24V which is the maximum value I can get "for sure" ...
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0answers
39 views

Generating varying output voltage [closed]

How do I generate a varying output voltage (40-80v) from an input voltage of 50V? (DC-DC) My input current is about 25A. Can it be done using flyback if I want to generate a power of 600W? What are ...
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2answers
55 views

Hot & neutral have similar voltage to ground: Finding the problem Part 2

I accepted an answer to a similar question recently, but I now have additional information and have realized that I need a more specific answer. I am nearly certain that my landlord will be unhappy ...
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1answer
50 views

Voltage divider or not? [closed]

How do I calculate the voltage in this case? Do I need to apply the rule of the voltage divider ( how? ) or not?
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0answers
41 views

voltage and current mode

I am reading about voltage mode and current mode from the book excerpt here. There is one part about current mirror that I don't quite understand. Could anyone explain it more details? A unity gain ...
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1answer
30 views

Voltage Spikes in AC voltage Controller

The diagram above shows my circuit. It is actually an AC Voltage Controller with PWM controlling the output voltage and a 1:2 transformer stepping it up to 230V. A 1.8uF capacitor is used as a ...
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1answer
47 views

Voltage divider with ADC

simulate this circuit – Schematic created using CircuitLab I am a newbie and this may not be a tough one. I am using Arduino UNO and trying to find the unknown resistance with the above ...
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3answers
59 views

Converting a 120V universal motor to run on 240V

Is it as simple as rewinding the field coils with twice the number of turns and wire half the cross-sectional area of the original? or would the armature coils also need to be rewound as well? The ...
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3answers
70 views

I want to decrease the voltage on my electric fence charger [closed]

I just installed a small electric fence in my backyard to keep my small dogs from clawing through the wood fence to get to the neighbors dogs. ...
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1answer
53 views

Voltage on a disconnected part of the circuit?

Here's an RTL NAND Gate. I am trying to measure collector-emitter voltages of both transistors when both A and B are grounded. Transistor-A's collector voltage is about 3V. My multimeter reads C-E ...
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2answers
86 views

Are SMT components bad for high voltage applications?

Majority of the assembly factories are asking for SMT jobs. My gut tells me through hole would be a better option for a high voltage application. Before the high voltage project is started, we need ...
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0answers
4 views

Create Car Battery Load from Smaller Batteries [migrated]

I want to determine if it is possible to chain together smaller household batteries to produce the equivalent output of a 12V car battery (temporarily). There is a practical reason for this bizarre ...
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1answer
27 views

How do I find Vab and Vcb in this series circuit?

In, general, I dont understand double and single voltage notations. How do I find Vab, and Vcb? Steps would really help.
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1answer
77 views

Best way to deal with voltage loss in batteries

I'm doing a project with Arduino. I have a small Arduino board that every so often takes measurements from a sensor, but it's idle most of the time -- consuming 6mA. I want to use a small battery to ...
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0answers
19 views

Charging NiCd 8S batteries with 12v (Replacing OEM charger)

I an trying to repair my friends cordless drill, and it turns out that the OEM charger does not work. The OEM charger (AC/DC) is 11,4v 250mA. The battery is a 8S NiCd rated at 9,6v. I want to use a ...
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2answers
285 views

555 timer with output voltage equal to 5V?

I am (still) learning about electronic and want to get a 555 timer. From a datasheet (page 5) it looks like when the input voltage is 5V, then the output voltage is only 3.3V. Is that correct? If ...
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41 views

Power supply with voltage and current selectors [closed]

Is it possible to create a power supply with voltage and current control through something like knob selectors? If there is, can I have a circuit diagram example?
2
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1answer
52 views

N-Channel Mosfet to switch a -48V to -54V Power Source

I have recently been tasked with the rebuilding of a resistive load center we use at work for testing telecom power supplies we have serviced. It currently has a series of relays that continually weld ...
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1answer
108 views

Digital circuit to compare two voltages

I have a task in which I have two sensors, each reading a voltage value. I want a circuit to output 1 if the difference between the two readings is smaller than 10% and 0 otherwise. I can solve it ...
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1answer
63 views

Is there supposed to be a voltage differential between V- and Earth Ground on my Power Supply? [closed]

I'm debugging something in my machine that's causing it to blow my communication chips (AtMEGA16U2 for USB connection) when I noticed a voltage differential of 0.3VDC-0.9VDC between V- and GND on the ...
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3answers
73 views

Torque in relationship to Voltage

Regarding a DC motor designed to operate at a voltage up to 22 volts: If this motor is powered by a 18.5 volt lithium battery, will it not produce more torque than if the same motor is powered by a ...
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0answers
61 views

How to protect IO pins from transient overvoltage?

I have a small PCB featuring a LTC2983 chip. I'm concerned about the possibility of transient overvoltage on the digital input pins (SCLK, SDI/MOSI, CS, Reset). The datasheet tells me that it detects ...
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2answers
159 views

How to build a “stable” voltage divider?

I'm trying to build a EMG (electromyography) acquisition circuit. In order to power the operational amplifiers I'm using a voltage divider with 6.2k resistances and the voltage from the wall is 18V. ...
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3answers
70 views

auto-recalibration of a power supply through something stable over time? (thought experiment) [closed]

Highly accurate instruments with a calibration are quite expensive, and anything electronic will tend to change over time. The effects of heat and oxidation, and perhaps changes in the material due ...
1
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1answer
47 views

Plug from laptop AC adapter was broke [closed]

When I tried to plug my AC adapter was broke. Here you can see it: It's only the wire so I can replace it without any problem from my AC adapter. But my question is: Can I use any wire (while it ...
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1answer
88 views

Can you help me solve this op amp? [closed]

What type is this Op amp? What is formula for calculating Vo.
9
votes
3answers
273 views
+100

Unexpected Sensor Output Voltage Rise

I'm using a Shinyei PPD-60PV particulate sensor in a product and I've noticed something very odd in testing, and I don't know how to explain it. It's connected to a WildFire board by way of cabling to ...
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2answers
262 views

How to step up unregulated ~0.2-1V to regulated 5V

For a school project, I am building a small hydroelectric generator. It uses a 10v, 600RPM/v brushless Tower pro 3520-7t-8 motor, which, when geared up (I'll spare you the calculations here), should ...
0
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1answer
51 views

Which one of these 5 pin 3 phase connectors is more standard? [closed]

Images: http://imgur.com/a/BItbR One is rated 16A "Dafr-164m" and another is rated 32A "Typ 2" We have a 16A breaker quite a ways from our house ~50m. We asked someone and they said they use both. We ...
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0answers
95 views

I need ANY Analog Multiplier schematic?

I need a working schematic for an Analog Multiplier (the device output is the product of two input voltages) as a small part of a university project. Have searched the internet heaps, but cannot find ...
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0answers
23 views

AGM Battery won't hold charge while powering - voltage drains

I have a 6V 2.9Ah AGM Sealded Non-Spillable Battery. When it's charged, it will hold and maintain almost 6V. When I connect the battery to the light that it's supposed to turn on, it still holds it's ...
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2answers
76 views

Transformer drawing 29x more current than it needs

I have an old transformer (20+ yrs) in a building I manage (GE Model 9T23B3872), it takes 277V 3-phase and converts it to 120V 3-phase. It seems very wasteful. It is drawing a combined 8.7 A @ 277 V ...
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3answers
100 views

why does sources with same voltage drive different current through same load?

I have three mobile phone chargers with rating 5V 500mAh, 5V 1Ah , 5V 2Ah. When I charge my phone Mi 4i with these chargers , the charging time is different. It means all these chargers drive ...