# Tagged Questions

Power consumption is the actual energy demand made on existing power supply (e.g. battery). Consumption of electric energy is measured in watt-hours, Wh.

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### Effective Capacitance of an FPGA board

I am currently designing a processor on an Altera DE0 Nano and found out that the power consumption of my design may be computed by this equation: P = C * V^2 * (a * f) where P is the power ...
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### Do longer wires consume more power?

In DC, for example at 12V, will a longer power wire (lets say 10 meters vs 10 centimeters) cause a high current consumption?
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### I don't understand the text about LED's type and power consumption

On my web-surfing, I found some information about LED's type and power consumption. I don't understand below (Red-lines.) Why 'common cathode' power consumption is lower than 'common anode'? Please ...
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### Pull up/Pull down power consumption [closed]

For a microcontroller, does pulling up a GPIO pin consumes more power than pulling it down? (I've got the option to pull a GPIO pin up or down)
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### Common Cathode vs. Common Anode (RGB LED) [closed]

"Power consumption of common cathode is lower than common anode about 30%" Is it right?
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### Current requirement in RS485 Circuit

I am using ADM2482, Isolated RS-485 Transceivers. I need to calculate total max power needed to Drive this circuit. Specs are 1. Logic side voltage is 5V 2. bus side voltage is 3.3V 3. Speed 1 Mbps. ...
1k views

### Why does voltage not appear in the battery life calculation?

I have a PCB with a few radio modules on it. In its various states it currently uses anywhere between 100 µA and 100 mA. I can calculate how much time it spends in each of its states over a given year....
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### DC consumption translation to AC consumption

I've a battery charger that can output 9v and 2.5A and I use full power from it that is 22.5W. Can I translate this power consumption from DC to AC current? My AC is 220V 50Hz, so I'll consume 22....
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### Opamp power consumption

Attached simulation of op-amp . Q1) In Op-amp ckt 1 has power supply of 20V and In Op-amp ckt 2 has power supply of 15V (rest everything is same). How current consumption is more in 20V rather than ...
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### 74LVC inverter gate power consumption

I am using a microcontroller to drive a flyback transformer. The driving circuit contain speedup capacitor as shown in the figure, as to protect the microcontroller from relatively high currents ...
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### Single LED powered directly from AC mains

Today I disassembled a power strip (power extension) and found a LED connected directly to AC with a normal resistor (not a power resistor). How is it working as I thought it would be burned in no ...
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### Power Consumption and efficiency

I know that similar threads had been answered but due to the fact that i am a beginner at electronics i would like to verify my measurements concerning about voltage total current and power ...
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### Measuring Power Consumption of a Mixed-Voltage Device

TL;DR How can I measure the power consumption of a system that uses power supplies with multiple voltage outputs? Background I need to perform some power consumption tests on a desktop computer. I ...
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### Piezo transducer current consumption

is there any way how theoretically determine the current consumption of ultrasound piezo transducer? I only know impedance for res freq = 50 ohms and excitation voltage around -170 V. Does the Ohms ...
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### Charge Rate Myth?

Many websites post that charging your device with a high ampere charger will heat up the device and depreciate battery life. Is this really true. I have a sony nex camera that uses 5v 500ma input. Is ...
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### Constant Current Load ampere measurement

I have the following circuit that I am building, a constant current load): I am using a 9 volt battery and a 1.5 volt battery to power the circuit. My load under test is a AA battery. Based on this ...
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Are there power consumption benefits between a discrete timer: astable multivibrator or some other; and an integrated circuit? I have a time dependent circuit in a project and I went looking for the ...
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### How can I monitor AC current in multiple wires with a single ammeter?

I'm looking for a cheap way to monitor my electricity consumption across multiple power plugs, on a per-wire basis (ie. I'm not looking for total power consumption across all wires) There are many ...
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### Charging all night and its effect on the charger

I googled about this topic and I found that keeping the charger plugged in the wall for days will consume a very small amount of energy and will not cost too much. And most of smart phones disconnect ...
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### 3V7 to 5V level conversion

In my product i am using a wifi module requires 3.3v and a bunch of other components requires 5v. For this i am using 3.7v 3000mAh battery. So here i have a doubt whether to use which case or any ...
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### Why does my resistor consume so much power?

I've created a low battery indicator circuit which lights an LED when the voltage drops below 3.75V. in this circuit, the 62ohm resistor is consuming about 240mW of power. why is this? is there any ...
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### how do i select a battery for a circuit which has multiple ICs?

I am using INA125 amplifier, a PIC controller, a load cell and a ESP 8266 wifi module. how can I calculate the power consumption to select a battery?Do I just add up the currents of my 4 devices or is ...
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### Unexpected reversed voltage over shunt resistor

I'm trying to measure the current consumption of an accelerometer using a 1kOhm shunt at Vdd. I've read that there's a ~30kOhm resistor at SA0, so grounding it causes a much higher current draw. When ...
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### How do “Inverter” or “IGBT” welders control CC and CV output?

I have a question on welding units. A lot of the newer units these days have "Dependable Fairchild or Infineon IGBT (non module)", "MOSFET design for Hobby use" and I can't tell if all of this stuff ...
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### Power for Strip lights

How many watts does a 12v 300 led - 5 meter strip light use roughly, is there a wattage per smd/led there 5050, I have a 5amp 12v = 60watts I think and was told that's more than enough, and I have a 1....
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### Calculating Energy Consumption

What formula can I use to determine the capacity of a USB battery bank (ex. emergency backup battery for a cell phone) to power a device that consumes x miliamps at 5 volts for y hours? I'm ...
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### Which device has lowest power consumption? [closed]

In one of my project I need to scale down 12V dc to 8V. For this purpose I know that I can use, Voltage divider using two resistors. An opamp with +ve feedback A dc-dc converter I know that I ...
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### Can I reduce energy consumption if I disable accelerometer's axes?

I'm using LIS3DH accelerometer, a 3 axes accelerometer to build a low energy consumption device. For now I just need the Y axis. If I disable X and Z, can I save more energy or the accelerometer use ...
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### Boiler feedpump energy consumption and safety [closed]

Is it advisable to use VFD on a boiler feed pump ?
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### How does a HT motor deliver profit

How is HT motor more beneficial over a motor of same power delivery. If the power delivered remains same in both types of motor for a given power delivered to shaft, how is one more useful than the ...
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### Problem with a solar power bank indicator LEDs

I bought a 10000mAh (actual 4000mAh) solar power bank from Victsing few days ago. After having solved a short-circuit problem that affected the solar panel, I noticed that it took an extremely long ...
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### 5 year run time on small battery

I am working on a project that checks a sensor every 12 hours and reports the status via cellular modem to our server .. Power consumption is less than 1mA during sleep mode and spikes to 900mA ...
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### PIC24/PIC16 power consumption during reset

I am working on low power application that has long Vdd rise time. I have external power supervisor that control PIC24/PIC16 MCU reset pin. It holds MCLR pin low during Vdd stabilization period and ...
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### Calculate power consumption for solar power supply [closed]

I have a project where I need to install 2 IP cameras and 1 radio transmitter in a remote location that will depend on solar power. The cameras and transmitter are 12V, DC and have a combined draw of ...
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### Calculating total power draw of device (camera) and accessories

I work with cinema cameras and at any given point the camera will be adorned with a number of accessories e.g. Monitor, Follow Focus Motors, Cinetape etc which are being powered by ports on the camera ...
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### Is it possible to measure energy consumption from power socket? [closed]

I wanted to know if it is possible to measure how much energy is being consumed in the entire house by plugging in a power meter in any power outlet in the house? I am aware of some portable meters ...
887 views

### HM10 Bluetooth (CC2541) put in to sleep while connected to iOS application

I'm trying to trigger an action on iOS application using HM10 Bluetooth module. And i have successfully accomplished the functionality, But now my concern is the power consumption, I have already ...
7k views

### How to calculate power consumption?

I have a Surface Pro 3 and am on the run a lot so I'm thinking about getting a deep cycle AGM battery to put inside my car so I have a constant power. I need to know and confirm some measurements ...
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### Rating 1.5V 50mA (MAX) what does it means?

I have an optic mouse that has in its specifications this: 1.5V -- 50mA (MAX). What does it means? Does it means it consumes 50 miliamps an hour? or the maximum consumption would be 50mA depending on ...
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### LED lamp increased power consumption after installation: Why? [closed]

I'm new here, but I've been checking your forum few times before, never registered. Anyway... I have a problem at my home. I'm not very electrical kind of guy, so these questions may be easy to answer ...
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### Can I increase the no of operating hours of a battery without increasing its capacity?

Setup Let's say I have a 12V / 1Ah rechargeable battery pack. A device that consumes 0.1A will run for 10 hours. When the battery drops to 8V, the voltage will be insufficient and the device won't ...
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### How can i find total power consumption of the device from its datasheet?

In datasheet which parameter should I consider as a power consumption of a device? What is Icc? what is Iin? To get total power consumed by device can I multiply input current Iin with input voltage ...
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### Do global variables consume more power than local variables in embedded systems?

Today my colleague from work said that access to global variables on microcontrollers consumes more power than access to local variables, unfortunately she did not explain that. At the beginning, ...
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### switch OpAmp down to minimize power consumption

I'm currently designing a board which senses some stuff. The board is powered using a 6V lithium battery. According to my sensor+OpAmp logic I need to split the voltage into +/-3V. The circuitry to ...
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### Do chargers use power when they're not charging? [duplicate]

1) If I connect my mobile charger to a wall socket and it is switched on, but I don't connect my mobile to the charger, does the charger still use electricity? 2) If I connect an extension box to a ...
2k views

### Piezo buzzer current consumption

In my DIY project I need to decide do I want to use piezo buzzer (for sonar-like device) or not. To decide this I need to calculate current consumption of this device. Parameters I was able to find in ...
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### Are BLE modules capable of working with a CR2032 battery? [duplicate]

I keep reading that the Bluetooth Low Energy modules are capable of working with a CR2032 battery for years, but their consumption is around 20mA and the max discharge of a CR2032 is around 3mA (200uA ...
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### What's the difference between logic/if system and drive system of a display?

I've been looking at the current consumption of a display and the datasheet says the following: Can anyone tell me the difference between "drive system" and "logic/if system"?