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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iPhone TRRS Circuit Not Working
So basically what I am doing is creating an FSK module that sends data to the iPhone via a 4 pin headphone connector (TRRS). So the FSK audio signal comes from the module, and into the mic pin of the ...
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Is there any disadvantage to running an op-amp off asymmetrical voltage rails?
On a PCB I'm working with, I have analog feedbacks running through op-amps into a 3.3V microcontroller. Thus, signals outside 0-3.3V are useless, and potentially dangerous to the microcontroller. The ...
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How do I determine what voltage sensor to use in replacing one in a touch lamp? [on hold]
I have to replace the sensor in a touch lamp. I've noticed that such items come in 110, 120, and 220 v. How do I determine which one is right for the lamp I have?
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Switching 9V using a NPN transistor and an Arduino
First of all, I'd like to say I'm not an Electrical engineer so please bear with me. I haven't got a sketch for what I'm trying to achieve but hopefully I can explain it ok.
I have an NPN transistor ...
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2answers
59 views
Need a simple circuit and IC for low voltage indicator
I have a battery operated power distribution system for some audio gear I use. I need to implement a multi-level voltage indicator via LED:
Green when the voltage is above 14VDC
Orange when the ...
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2answers
67 views
Can I use a 0.7A charger in place of a 1A charger? [on hold]
One problem that I usually come across is the current ratings on mobile phone chargers. Right now, I need a 1A charger (which was shipped with my phone) and I have a 0.7A charger handy. Both the ...
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pulse voltage drops trying to connect 2 devices
Hi I try to connect 2 devices. The first one sends a pulse to the second. The second has a 3.3 V input. And the output pin from the first device has a voltage of around 7.3V. VCC of the first is 12 V.
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63 views
Replacing 12 x (internal) CR2032 batteries with one (or more) external batteries
As Christmas was on a budget this year, one of the presents I came up with consisted of a fishbowl with battery operated (flat CR2032 3V) tea-light candles in the bottom, these were covered in ...
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Interfacing two PIC microcontrollers, of different power sources?
I have two different circuits with 5v for each, and they are using PIC microcontroller, how can I send a data (voltage) from the first PIC using output pin to the other PIC using its input pin? I ...
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2answers
157 views
How can a small device produce two million volts? [on hold]
After reading a shopping magazine, one of its products featured a stun gun the size of a large wireless car door opener* with the ability to produce two million volts. How can a small device ...
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2answers
136 views
For how long ICs can be exposed to overvoltage without being damaged? (protection circuit evaluation)
I'm asking this because i'm trying to develop an active overvoltage protection circuit and unsure about how quickly it should react to overvoltage condition. Maybe someone can give me advice on that?
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Can 12.74V (iso 12V) result in a PC not booting anymore? [closed]
My desktop PC doesn't boot anymore (no leds, no fans, ...).
Last week, we could get it started by toggling the power switch a couple of times
but this doesn't help anymore.
I tried
replacing the ...
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1answer
50 views
Calculate the appropriate bias voltage (and resistor) of a condenser microphone
I have a condenser microphone that has no any model name or number. As we know condenser microphones need a bias voltage for operation. Some microphones need \$2 V\$[1]. and some need more. As we can ...
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63 views
Crosstalk between secondary transformer windings
I have hand wound a transformer which has a 220v primary winding, two 25v secondaries and a 15v secondary:
simulate this circuit – Schematic created using CircuitLab
I have centre tapped ...
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3answers
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Having trouble understanding amps, watts, voltage, and how they all work [duplicate]
I read that watts is amps multiplied by voltage.
But then I read that it depends on the wattage ... what determines wattage? I thought that the outlet supplied voltage potential, and the device uses ...
