# Questions tagged [power-consumption]

Power consumption is the actual energy demand made on an existing power supply (e.g. battery). Consumption of electric energy is measured in joule (J), but for practicality often watt-hours (Wh) are used.

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### How can I calculate how much power an isolation transformer itself consumes if no load is provided?

Isolation transformers usually come with these measures: Voltamperes Voltage Current In my case, I want to know estimate how much an isolation transformer will consume without a load using these ...
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### How I can calculate/estimate how many voltamperes I need for an isolation transformer?

I need to power an ungrounded device with live chassis. According to my Google fu I can protect myself using an isolation transformer: https://www.youtube.com/watch?v=3rvEdHyAd2k. Of course I am not ...
63 views

### How to calculate actual power consumption off of a battery through inverter

I'm sorry if this is not a bright question. If Watt = Volt x Ampere: If I have a 12 V, 100 Ah battery that'd mean I can use 12 x 100 = 1200 watt an hour assuming I can use full 100 Ah and have a 100% ...
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### Measuring how much current a tablet style device draws

I wanted to measure how much current a usb-c device (specifically, a reMarkable 2 Tablet, but this could apply to any device) draws when in use, so I bought one of these: I hooked it up and got a ...
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### If a MOSFET is maintaining a singular state what will the power consumption be?

https://docs.rs-online.com/ec6b/0900766b811b5c5c.pdf Taking the MOSFET driver from the attached data sheet (1.5A 30V), if the MOSFET wishes to remain on for a period of 24 hours does it require the ...
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### Optimizing power efficiency: Troubleshooting high power consumption in analog reading circuit

I've been facing some issues with my analog readings. The problem has been somewhat resolved using the following circuit design: You can find more information about the circuit's 'function and its ...
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1 vote
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### BD8306MUV and idle current

I need to generate 3.3 V from a 3.6 V battery to power a sensor. I choose the Rohm buck-boost converter BD8306MUV for that, but I discovered that it consumes nearly 5 mA of current in idle mode ...
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### How to create a power latching circuit without to exceed the GPIO specifications of an battery driven esp32 for a zero current power consumption

I want to operate an ESP32 with a 9V battery pack. In-between there is power latching circuit which is responsible for feeding a LDO voltage regulator with power for the micro controller module (ESP32)...
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### What's the meaning of RF power consumption given in mA, not in mAh?

I'm trying to understand the power consumption of an esp32 with BLE enabled and transmitting. Its datasheet provides the following table: As you can see, it provides the power consumtions in mA. I ...
138 views

### Excessive power consumption on "AND" gate

I have an issue with an IC "and" gate (SN74AUP1G08) that has a power consumption that is way higher than what is indicated in the datasheet. Indeed, the datasheet indicates that the maximum ...
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### How can I maximize the power consumed in this resistor?

simulate this circuit – Schematic created using CircuitLab I have gotten really stuck on this question. The question is: Determine R3 so that maximum power is consumed in R3. What is that ...
1 vote
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### UART line causes exess current consumption

I'm currently working on a project that involves an STM32WB55 microcontroller, a GPS module, and a LoRa module. I have encountered an issue where, when I put all these devices into sleep mode, I ...
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### How to work out consumption of a battery after powering an electric motor?

Hi friends I'm trying to work out how many kWh of energy capacity are drained from a high voltage battery after powering an electric motor for a period of time in a little study on an electric vehicle....
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### How to use a load profile to calculate energy consumption

I usually receive electricity bills from the utility but due to issues on their end, they haven't sent me bills for the several months. Instead they gave me a load profile for a few months which has ...
63 views

### How to calculate watt-hours used by the @channel Slack notification sound

Imagine someone used @channel in a Slack channel with 100,000 people. How many watt-hours are used to play the Slack notification on the laptops for these 100,000 ...
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### Data collector: how much power will my system use (Linux vs. RTOS)?

This is about a data collection device. It mainly contains a Linux operating system, various data interfaces such as RS232/RS485/CAN/SDI-12/RJ45, etc., and a communication module for 4G and satellite ...
1 vote
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### Best way to calculate Energy used in a circuit

I'm trying to figure out how to calculate energy consumed through my circuit. I can read the current and see the voltage, can obviously calculate the instant power, but I'm fairly certain that I don't ...
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### Can I use a power bank to power my laptop during a blackout? [closed]

I am wondering if it's possible to use my ThinkPad L430 laptop with a power bank as a power source during a blackout. The laptop's power consumption is between ~35 to ~42 watts. Its battery is always ...
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179 views

### Typical efficiency of logical circuit outputs

When looking at "logic" circuits (gates, level shifters, ...), usually intrinsic current consumption is specified, and is often quite low (compared to maximal recommended output currents of ...
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### How to limit power consumption to a certain value?

For the SAE Aerodesign competition, there is a requirement to create an electric RC airplane that does not exceed 750 W of power consumption at any time. The electrical circuit consists of a 22.2 V (...
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### How to define the stop mode command? (S08DZ96)

I am using MC9S08DZ96 microcontroller and I using CodeWarrior version 11. I want to put the MCU to sleep mode(STOP3). In the CPU settings, I have changed the sleep mode setting and the relevant ...
634 views

### How much power can a 6 nm transistor handle?

Modern semiconductors are manufactured with feature sizes measured in nanometers. For example, the EPYC 9654 CPU has 78840 million transistors. Each one is in 6 nm and has a TDP of 360 W. What is ...
1 vote
2k views

### How do I calculate the required batteries and solar panels for my needs?

I am building my camper and want to know how to calculate exactly what batteries I need, and what solar panels to meet my needs. Here is my list of the main and most powerful devices that I will use, ...
881 views

### What is the meaning of average current? How is it used in calculating battery life?

The average current is the total current consumption divided by the measured duration. As per the above image, there are two average currents. Case 1: 866.82 uA over 2 mins of windows (complete cycle)...
206 views

### A budget oscilloscope for power consumption measurements of PCB [closed]

I'm working on an IoT project based on BLE (2.4 GHz) and SoC: nRf52832, and at this point, I need to do some power consumption measurements. After going through some previously built similar projects, ...
1 vote
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### Need help determining LED run time given a certain battery

I have struggled to determine if a single CR2032 battery is sufficient to run some LED lights for a long enough period to replace the 2 AAA recommended for a DIY build. I'd like to use CR2032 instead ...
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### Why do power meters claim not to be usable for air conditioners? [closed]

As the title says, why do some power meters (especially the ones readily around where I live) claim that they cannot be used with air conditioners and a few more devices? One typical such device can ...
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### Is the output power of nRF24L01+ dependant on power supply level?

I'm making a low power sensor node using a nRF24L01+ module in always-TX mode, powered by 2xAAA batteries. Considering the minimum voltage of 2v when batteries are depleted, the device would still ...
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### Durability of a battery

I have a device that consumes 10W and I have a 12V x 4.5Ah = 54Wh lead-acid battery, does that mean that my device can work continuously for 5.4 hours? Does the same concept apply to lithium batteries?...
1 vote
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### The LED bulb in my room has written 9 kWh/1000h on the box; what does that mean? [closed]

I bought a LED bulb for my room which uses 8.2 W power = 60 W conventional. I know this means it's a 8.2 W LED bulb which gives a brightness equivalent to a 60 W incandescent bulb. So here it says 9 ...
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### Resistor losses in heat

I am trying to understand the power lost via heat (friction) from a resistor as opposed to what flows through and is available for the next component in series, and how I estimate this. I have read a ...
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### Arduino board consumption benchmark

I know consumption depend of the type of application, but I would like to know if a comparison of average consumption exist between arduino and similar boards (Teeny/Dfrduino...). The board I am ...
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### Help me understand the calculation of the current consummated by LM7805

Please help me understand how to calculate the current consummated by LM7805 during its work. Parameters: V(in) = 12V V(out) = 5V I(load) = 10mA (0.01A) The image ...
590 views

### ATMega32u4 power consumption with CLKDIV8

I have a little board with an ATMega32u4, that's run straight off USB voltage. There are no peripherals on board that should draw power (no LDOs or anything, LED is off). It has a 16MHz crystal. The ...
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### Calculating watt usage from an input/output electronics spec for step-down transformer's minimum watt limit

I'm trying to calculate the minimum watt limit needed for a step-down transformer that convert 220 V to 120V from source (220V) to 125V smart plug then to an electronic appliance with the following ...
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### how to read power labels on home appliances?

I want to know how to read the power label of a home appliance in order to estimate energy cost. I have provided a picture of an example power label What i understand from the provided label is I use ...
1 vote
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### ESP32 bootstrap pins power consumption

The other day, I tried that connect to GPIO15 and GPIO5 GND with 26.7 kohm pull down resistor despite having a internal pull-up beacuse of IO obligation. I had no problems during a booting. Please ...
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### How do I compute the power consumption of an audio amplifier?

I intend to use this audio amplifier in my project : PAM8019 It has two analog inputs : left channel and right channel. It has two analog ouputs, which are the amplified inputs. Let's say I follow the ...
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### Gasoline generator + Peltier configuration

I have a DIY cooler box with Peltier element 12V/3A/27 watts and want to connect via power supply to gasoline generator with output 600W at 5A max. Would that be a problem and not supply my Peltier ...
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### Does an amplifier consume any power when nothing is connected? (GPD2846A built-in 2W amplifier) [closed]

The GPD2846A module has a built-in amplifier into it. However, I want to use it with my headphones which don't require 1-2W (they are definitely going to distort sound and possibly be damaged). So I ...
1 vote
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### VL53L3CX XSHUT PIN PROBLEM IN DEEP SLEEP

I have project using a VL53L3CX distance sensor. Also , I control it by ESP32. In normally, I can command to XSHUT pin. And I can read xshut pin of ESP32 that is 3V3 or 0V. But, When ESP32 enters deep-...
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### How is power consumed by an induction motor calculated based on speed (from a VFD) and torque induced by the rotor shaft?

I've been tasked with carrying out some design improvements on my company's production floor. There is a flat belt conveyor assembly line, whose movement forward movement is controlled by a single ...
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### For a mathematical operation in CPU, could power consumption depend on the operands?

Obviously, the number of operations affect a CPU's power consumption, but does it solely depend on the operations themselves? For example, adding 0 and 1 involves setting one single bit, but adding ...
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### How does this LED last this long?

Before the end of last year, dad asked me for some small red light for his cabin, to pretend there is an alarm activated. He wanted it battery powered, so it can glow when electricity is turned off. I ...
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### STM32F030 High current in stop mode

I would like to put STM32F030K6T6 into STOP mode (low power mode), in which there should be current consumption around 5 μA. But whatever I do the current consumption is around 450 μA in stop mode. ...
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### Lower idle current - battery powered ESP32 circuit

I am building a Li-ion powered circuit to power a remote night light. The mA values were measured with a cheap multimeter, I guess at least the deep sleep current of the ESP32 is actually lower. The ...
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### Do higher voltages cause heating?

I'm trying to wrap my head around energy consumption in general. For some background info, I'm an engineering student and am familiar with the usual electrical engineering formulae Here is what caused ...
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### Can increasing the wire gauge reduce your electric bill?

I was in a seminar and heard the presenter say something I am not able to understand. The statement was that if you use a higher gauge wire it would help reduce your electricity bill. Since I was not ...
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