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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amplifying 555 astable multivibrator output

I am using 555 as astable multi-vibrator and its output is a square wave of 7 V and frequency is around 800 kilo hertz.But i need to increase the voltage to about 40 V . What should i do?
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2answers
80 views

Does the voltage drop “pass” like current?

Q: Suppose this diode is silicon. So it can't have more then 0.7 voltage drop. If,after the diode has aquired 0.7 volts, more voltage comes from the voltage source,then what happens? Does the diode ...
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48 views

+15V and -15V from a 24VDC Power Supply

Is it possible to get both a +15V and a -15V from a 24V power supply? This is for powering a controller MKS 2179A.
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3answers
50 views

Getting the desired output voltage swing from the op amp output

I am designing a microphone preamplifier circuit. I have used op amp OPA 37 which amplifies the signal coming from the microphone to be used by the ADC. The usable voltage range of ADC is 0-2.5V. I am ...
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48 views

Discrete BJT Voltage Controlled Op-Amp

I recently asked about building a transistor controlled variable gain differential amplifier for a project I'm working on. The configuration I used was less than ideal and I am researching different ...
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2answers
39 views

TL074 or TL072 VOL (output voltage swing low)?

TL074 or TL072 VOL (output voltage swing low)? I can't find it in any datasheet. I want to know how low the output can get if Vdd=9V and Vss=ground (0V). If I read the datasheet right, VOH (output ...
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4answers
221 views

LDO or Switching for 24V Input, 5V Output

I have a 24VDC supply that needs to be regulated down to 5VDC to power an Arduino Mega and a XBee Series 2 module. How would you choose between a Switching Regulator (LM2576T) and a LDO Regulator ...
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2answers
103 views

Amps and voltage [duplicate]

I am learning about electronics and micro controllers. I started with the basics and have came to the chapter in my book about currents etc. Now, I am a little confused with voltage and amperage. Am I ...
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1answer
36 views

Differential gain of amplifier with current mirror

Consider this pdf document, pages 58-59-60. It is a differential amplifier with a current mirror as active load. According to that document, if I take the unbalanced output in the right-hand branch ...
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2answers
43 views

Reading a 1.2V-8.8V Signal into a 5V Arduino Input

An analog DC signal that ranges from 1.2V to 8.8V (from a thermocouple amplifier) is to be read from a input pin on the Arduino that reads 0V to 5V. Other that using a potential divider consisting of ...
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1answer
49 views

Powerstrip's red indicator is flickering like crazy as long as no light is turned on in the room

I have a Belkin power strip with a red light indicator in it. I have used it for years and it functioned properly. Last night I noticed its red light flickering like crazy, i.e. constantly turning off ...
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2answers
31 views

Power Supply amp doesn't match with adapter. Can I use the adapter? [duplicate]

Can I use this LCD display: http://www.itontec.com/product-detail/product-name-7/ With this adapter: *Display Specs: Power Supply(5~12V 2A) *Adapter Specs: Output: 12V - 1A Is that safe to use ...
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1answer
39 views

Voltage Output of a Current Source in Parallel and in Series with a resistor

Hi All, I imagine this is a pretty basic question to ask but I'm struggling to get my head around this. I'm trying to find \$V_{out}\$ of the circuit above. Now I understand why \$V_{out}\$ can be ...
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1answer
38 views

Finding V(l) for t>0 in RL circuit

One of my problems asks me to find the voltage at time greater than zero. The first part of the question asked me to find current. I was able to solve that part and found it using the general solution ...
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1answer
72 views

Heavy duty voltage resistor to decrease voltage from 120V to 100V

I have number of devices (total output 10000 Watts) that do run a bit hot when connected to 120V and are running in hot environment. Our research (using variac) have shown that dropping the voltage ...
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1answer
46 views

finding I(current)

I am learning about step response in RC and RL circuits and one of the problems i managed to redraw as the image above; however, when I am solving for i the answer is -5mA. I am just confused on why ...
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0answers
63 views

Do all 12V batteries produce the same amount of current? [migrated]

I have a car battery which is roughly 12 V. Sometimes, I don't use the car for a week (I bike instead), and the battery voltage drops to 9.5 V ~ 10 V. This low voltage makes it hard to start the car. ...
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2answers
50 views

Finding Vc in this simple circuit

simulate this circuit – Schematic created using CircuitLab Forgive me if it's a basic question, but I am stuck with this. Is this the correct way to do it: Do voltage division between R1 ...
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2answers
45 views

Constand output voltage from batteries / rechargable batteries

I'm trying to make myself a battery pack for my DSLR camera. The original battery of the camera has 7.2 V and 1200 mAh. I've also bought a coupler ( a dummy batterie for external DC input ) which ...
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1answer
43 views

Difference between a series circuit or parallel circuit in power generation?

I wanted to know the difference between the induced-EMF and current, in a series circuit layout, vs a parallel circuit layout. In a series the current would stay the same,however, the induced-EMF ...
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1answer
45 views

Two opposing voltage source, of different current capacities?

If two voltage source of the same value(20V) are wired in series and they both have different current capacities, could there be any current flow assuming the resistance(internal & circuit) are ...
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2answers
52 views

How to regulate voltage into two variable outputs?

I'm thinking of building a control voltage generator for a synthesizer. Basically I want to control two pitch control voltages with variable resistors, something like this: R1 needs to control only ...
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27 views

Problem to solve power [closed]

can any one solve this problem for me !! PROBLEM! A resistance of 5 ohm has a current i = t x 5x10**3 amperes in the interval 0<=t<=2 mili seconds. obtain the instantaneous and average power
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1answer
135 views

Is there a way of dividing 2 DC voltages? ie Vout = V1/V2

I need to take the ratio of two filter outputs as part of a project. I converted them to DC voltage values using a rectifier and a smoothing capacitor thinking that this would make division easier. ...
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22 views

Mesh analysis confusion — resistor polarity

I used mesh analysis to find Vo in the figure below. However, my set of equations just end up cancelling each other when I do the math. I am also not sure if the polarity of the resistors changes ...
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2answers
69 views

How exactly does a comparator work?

How exactly does a comparator work? Comparators have many uses and its concept is not too hard to grasp. What I don't understand however is how exactly it compares two voltages. How does it know ...
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37 views

Vape Pen Circuit, 3 main components. Wiring/component help?

I'm looking to control a vapor pen with a variable voltage (adjustable PWM that dictates a MOSFET), followed by a SPST toggle (safety), followed by a momentary that dictates another MOSFET. The goal ...
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0answers
121 views

Supercapacitor discharging

I had bought a Maxwell ultracapacitor (this one) rated for 1200F at 2.7V. Its ESR according to the datasheet should in ballpark of 0.4 milliohms. It got delivered today and is undamaged and new by ...
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1answer
42 views

Viability of Voltage Controlled Amplifier circuit

As part of the synthesizer project I have been working to design a simple voltage controlled amplifier. Due to the complexity of other parts of the circuit and the amount of time I've spent on this ...
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2answers
119 views

brief explanation of Ohm's law

How can I calculate ideal values of current for both short and open circuits by using Ohm's law. Further more usually said that it is not advisable to connect DC batteries of different voltages in ...
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0answers
35 views

Regulating voltage in an e-cig [closed]

I was hoping you could help me because I am an electronic cigarette user and would like to make one for myself. I was thinking of wiring 2 12V batteries in parallel,but since I use different ...
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0answers
34 views

fuse metal alloy with high springiness?

Is there a fuse alloy that would have the same springiness as this except with a little wire that comes out and that plugs into something, so that it could be machined and pressed from one single ...
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44 views

Arduino voltage drop while communicating with another Arduino [migrated]

I have an Arduino Uno rev 3 and an Arduino Nano in my Setup. I want to create a proof of concept, where one Arduino triggers the other via the Digital IOs. Arduino 1 sets a blinking signal on a ...
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2answers
290 views

How can I protect this 48VDC device from overvoltage?

I'm powering this isolated DC/DC converter from a power supply that is a nominal 48V, but could potentially reach a maximum voltage of 56V. The datasheet for the converter says that the absolute ...
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1answer
55 views

Power consumption / voltage regulation

Ok so I am looking to regulate a 6v power supply down to 3v Constraints are: Extremely limited board space (no room for any IC) Must be power efficient as the module is powered by 2x button cell ...
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4answers
73 views

Max potential difference that can be created in an analog signal using a microphone

I am a total newbie. The main idea behind all this is that microphone produces analog signals which are fluctuation in Voltage.. So can I use an amplifier to amplify these Voltage? And after it can ...
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2answers
69 views

will i damage this toy motor by running it on a higher voltage? [closed]

I have a hand held shaver that is chargeable. the socket plug for the device says 02A250V- and the green battery inside the device looks like this: and the ...
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1answer
71 views

Why do I experience a voltage drop between logic gates when combining multiple gates (7408 and 7402)

I am trying to combine logic gates (using ICs instead of trying to piece them together using transistors or MOSFETs). Below is the simplest example of what I am trying to accomplish, though ...
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0answers
45 views

Increasing output voltage, by inducing an EMF

I have a concept and wanted to verify it's possibility. I would like to induce and EMF that would increase the output voltage, but putting one of the wires in a parallel sub-circuit in a changing ...
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0answers
54 views

Best Way to Extend 30A 120v circuit over 300 feet? [migrated]

I have an old barn to which i'd like to provide electricity. The problem is that the barn is about 300 feet away. I understand that voltage drop over 300 feet is fairly significant. Buying thicker ...
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1answer
19 views

Max Voltage of Electrical Stimulator for Cardiac Tissue Bioreactor

I'm designing a bioreactor that will electrically and mechanically stimulate cells in media in an incubator. I'm using monophasic, square waveforms and have a max stimulation level of 12V/cm, else ...
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2answers
64 views

How much voltage to give my IR LED?

I got a new IR led, emitting light at 850nm. It says 5v reverse voltage and 1.5 forward voltage. How many volts should I give it? I have DESTROYED three other IR LEDs because of giving them too ...
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3answers
68 views

Feeding higher voltage sine wave to Arduino interrupt pin

I want to use Arduino to count cycles from a bicycle generator. This generator has variable frequency (which I want to measure), but also variable voltage that is proportional to wheel speed, ...
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1answer
67 views

Figuring out the voltage at a point?

From the following diagram: simulate this circuit – Schematic created using CircuitLab What would the voltage be at point b? 5V? And for point a would be 10V? Likewise point a(10V) ...
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1answer
25 views

Node voltage for simple circuit

This is probably a dumb question but I'm not sure what voltage is on this specific node. Also ignore values, they are random. Is it considered 0V or +V3? Then would the voltage drop of R1 be V2 or ...
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0answers
36 views

Power the Adafruit Neopixel

I've had a Neopixel stick lying around for a while and I've decided to give it a home on one of my multirotors. Unfortunately, I can't seem to get the wiring right. When I connect the battery, the ...
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1answer
39 views

How to connect PWM output from a dsPIC MCU to 12V LEDs?

How to connect PWM output from a dsPIC30F MCU channels to 12V LED diodes? 4 x PWM channels will be used. For use with following voltage: LED Voltage: 12V Total operating current: 5A 1W ...
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1answer
47 views

How does switch interfacing work?

This is a basic question, but I don't have a background in electronics so I find it difficult to wrap my head around the concept of how current flows. I have chosen this simple example of interfacing ...
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57 views

Charge pump configuration

Can anyone please explain the charge pump config. in this circuit. I am having a hard time figuring out what the diodes are used for, and I am not sure I fully understand the caps config. either. ...
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45 views

Why do some Arduino relay modules can handle up to 250 VAC but not above 30 VDC? [duplicate]

When you look for "Arduino relay module"s, you usually see one form "SONGLE" that says on it: 10A 250 VAC 10A 125 VAC 10A 30 VDC 10A 28 VDC My ...