Questions tagged [low-power]
Low-power refers to electronics that are designed to use less power than their common counterparts. This is often a requirement because of limited available power, as in battery operated devices, or in cases with limited cooling capabilities, as in notebooks.
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Low power RF switch [on hold]
Sorry about my noobie question but here it goes: I am trying to control the rainbird 9V latching solenoid valves on my garden with arduino and esp8266 but the catch is, there is no electricity where I ...
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52 views
Reducing current consumption for a PIC16 in Sleep mode
This might appear as one of those tens of questions that ask about power consumption on a PIC microcontroller. But after I have failed to reduce the current consumption to an acceptable level despite ...
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1answer
106 views
Why different SOCs have different CPU power voltages for given frequency?
Recently, I studied dvfs tables for 3 SOCs: exynos8890(LITTLE cluster), exynos7880, snapdragon 625.
Here is the result:
octave source code
The point is, that different SOCs with pretty same ...
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3answers
126 views
Why “Supports 5V VCC operation” appeared in LVC family datasheets?
Looking into the LVC logic chip family I was aure that it is 3.3 V supply devices. One of our fellows also confirms it here. This manual dated 1999 states that LVC is 5 V tolerant (version A), but not ...
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2answers
108 views
Watchdog with long on and off periods for microcontroller [closed]
I have a microcontroller (Arduino-like IoT device) and would like to connect a low power external hardware watchdog to be able to recover from failures. I know that a software watchdog is already ...
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28 views
Travel Photography 3.5V 3,6-4,8A LED Lamp powered by power bank
I travel a lot for my work as a photographer. For this I'm building a custom full spectrum lamp.
I have no issue running my build with a normal adjustable power supply from my studio.
To be able to ...
3
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1answer
62 views
Rectifying reversible polarity battery with minimal power loss
I'd like to build a battery-powered DC power supply that will accept a single-cell battery in either polarity (i.e. it doesn't matter which way you put the battery in). I'm thinking of using the ...
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1answer
46 views
Sleep vs low frequency
Some processors have a low frequency mode for using in low power mode.
For example MSP430 microcontroller can work in both
Normal clock frequency 16M Hz
Low clock frequency 32 kHz
I am wondering if ...
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35 views
Low power, low profile binary indicator
I am looking to find a way to communicate an alarm on a tiny device with a very low profile low power consumption component. The alarm is binary in nature, basically it is either on or off.
LED does ...
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2answers
155 views
How to efficiently read a battery voltage level with ADC
There is a circuit powered by a battery (3V button cell) and another circuit with a microcontroller (Attiny85 in my case) reading perfectly the battery level (through ADC3 pin) each 5 minutes interval....
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87 views
Powering down parts of a pcb to conserve power, is it possible? Any caveats?
I'm building a USB 2.0 bus-powered STM32F429-based audio device that is able to run in a stand-alone mode from a phone charger, or running as a USB device when connected to a computer.
To comply with ...
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18 views
Indicating “image not displayed” from downstream via DP/HDMI/DVI
I'm trying to switch a video signal between different sources and, as a courtesy to the device generating the signal, would like to indicate that the image data is currently being thrown away so it ...
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1answer
30 views
How to power a device with a LIPO battery correctly
I have a little device which is normally powered by 5V 2A.
But the manufacturer says it is compatible up to 16V 2A and I tested it with a powerbank which outputs 12V 2A.
Sadly this powerbank is a bit ...
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2answers
28 views
Counting pulses in low power device
I have a mechanical water flowmeter with reed switch output and I connect it to my low power, battery powered device to count pulses.
The reed switch is connected to my device via a 15 m long cable ...
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1answer
52 views
Understanding Low Power Solution
I have a device that is powered off of a large battery. This device has peripherial ICs on it that consume power. Right now I have the input voltage through a switching regulator to 5 volts and then ...
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1answer
50 views
Turn on power when voltage higher than set value
We are trying do design a circuit which works by harvesting energy from a split core current transformer. Most of the electronic works correctly, we use a 1.5F 5.5V SuperCap to provide enough power ...
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0answers
68 views
measure 4-20 mA and also power from loop powered
we know to give a command to an actuator in instrumentation we use 4-20 mA loop power. for reading this 4-20 mA I used the circuit below.so the problem is if my circuit only consumes 3mA, how should ...
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5answers
264 views
Diode type with lowest drop voltage [duplicate]
I make a small solar energy harvester. I'm searching for the type of diode with lowest drop voltage. Any suggestion for the type of diode for me ?
Thank you
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1answer
40 views
Mosfet or bjt choice for low voltage joule thief application
I make solar energy harvester using joule thief circuit with a small solar cell as the input. The output voltage from the solar cell is 0,5V. But the generic transistor, exactly silicon material need ...
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0answers
138 views
Could i get some circuit design feedback?
I have a computer science background and this is the first circuit I've ever designed. It is a lot of fun designing these circuits, but it also always feels like I'm missing a lot of "obvious" common ...
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1answer
31 views
Measure power usage of battery powered device
I'm a software engineer by trade so I'm a bit at a loss. Maybe I don't know the correct words to find what I'm looking for.
I have a Bluetooth Low Energy remote control powered by two AAA batteries. ...
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2answers
154 views
Turn on microcontroller by sensor, auto power off - how?
To minimize battery power consumption I want the microcontroller only to be powered when a sensor's output is high. After the microcontroller finishes a task, it should cut its power off again.
I ...
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2answers
73 views
Diodes - minimum forward conduction current
I've been working on a GPS tracker which is intended to run/idle on a battery for an extended length of time (2+ years). The tracker uses an accelerometer (LIS3DH) and remains in a sleep state until ...
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2answers
68 views
I want to boost 0.45V and 0.6mA to 0.7V and 3mA suggest me a circuit which can do that [closed]
I'm doing a project that basically transfer the power from a laser and light up an led using it.
The power output we are getting from the laser is at most 0.45V and 0.6mA (we used photodiode to ...
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1answer
32 views
Increasing TPS63001 Under Voltage lockout from 1.8V to 2.5V for use with LiFePO4 cell
The Under Voltage Lockout threshold for this chip ranges from 1.5 V to 1.8 V. I want to use this with a LiFePO4 cell, whose minimum voltage is 2.5 V.
With reference to the datasheet here, the VINA ...
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1answer
61 views
Switching 1875 Volts through a relay
I am trying to create an electroadhesive device that I can switch on and off easily, however, after using one relay that worked beautifully to do this function, I went out and bought a 4 channel relay ...
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0answers
46 views
How to reach ultra low power on STM32Lxx?
I'm having some problem reaching the said ultra-low power available for the STM32Lxx series. With no active register, the UC should consume around 10 uA, but I can't get it down from 1 mA. The ...
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0answers
13 views
Are components in PSOC 5lp powered off automaticaly?
I was reading an article about saving power in PSOC 5 (here) and its says it's a good practice to power off the unused components, but my question is: if I don't have a component block in my project, ...
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3answers
87 views
Ultra-low power sound/audio sensor for LOUD noises
I'm searching for a sound/audio sensor with ultra-low power consumption to detect the presence of a really loud noise (100dB+). The controller runs on battery and there is no option for a different ...
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2answers
57 views
what is the right power supply switch for a sensor?
i'm trying to control my sensors power supply to reduce the current consumption of my project.
i'm using ATmega328p that collect information from different sensors (digital and analog sensor) and send ...
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1answer
38 views
How does Flash*Freeze reduce power consumption in Microsemi FPGAs?
Microsemi FPGAs are marketed as being low power. They have this flash freeze mode that is supposed to achieve much lower power dissipation, down to micro watts.
I am trying to understand how exactly ...
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1answer
91 views
Where do I place the on/off switch in a multi voltage circuit?
I've got a simple Arduino setup where I need to supply a 3.3V Arduino with adequate power - and at the same time provide higher voltage to a sensor which needs 5V.
The Arduino is powered by bypassing ...
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1answer
117 views
DC Current Measurement (resolution of ~ 1 uA)
I haven't worked with electronics in a long time, and now have the task of measuring the power consumption of a low-power device I'm writing firmware for...
When the device is drawing very little ...
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4answers
938 views
What's causing this power spike in STM32 low power mode
I'm using an STM32L073RZ on a bare board with just the CPU and decoupling caps. I'm powering the board straight from an Otii Arc and measuring current consumption. I'm running MbedOS 5.11.2.
When I ...
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3answers
418 views
How to debug current consumption with STM32 Nucleo board?
I'm trying to configure an STM32L011-Nucleo developement board to consume about 600 uA of current or so. It uses an STM32L011K4.
The datasheet states that this should be possible if I drive the MCU ...
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3answers
101 views
Power small microcontroller from motherboard RJ45 ethernet port
I'm wondering if it's possible to power a microcontroller (e.g. ATmega328) from a Ethernet RJ45 motherboard port. Unlike USB, there is no power line, all pins/lines seem to be data only.
I am ...
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0answers
250 views
STM32 L0 wake from STOP mode with WAKEUP pin
I am attempting to wake an STM32L073RZ from stop mode using WAKEUP_PIN_1. I'm running MbedOS 5.11. Unfortunately throughout all of the documentation (Mbed/STM) I ...
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0answers
32 views
Data communication in power harvesting project
I want to design a wearable gadget for elderly to detect falling. This gadget should work by energy harvesting. Now I want to find the best effitient way of power consumtion to send data to a station ...
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1answer
41 views
Low power device with high current peak
I'm creating power supply for controller that usually operates with very low power consumption, but sometimes needs high power. To make the situation harder there is "sometimes" external power present ...
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1answer
49 views
Harvest energy from ultra low current and high voltage source?
I have a sensor which can produce voltage upto 10 V but can only produce 50 nA of current. I tried to harvest energy using TI's BQ25570 evaluation board but the current is too low to kickstart the ...
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0answers
43 views
Power off detection circuit to close opened latching solenoid valve
The image above is referred from this SO link. My use case is the following:
A latching solenoid valve, which would be run using 4 AA batteries (6V)
Solenoid Valve (9 Ohm) operates at 6V under 40ms ...
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2answers
105 views
MSP430FR5994 SVSH Interrupt from LPMx.5
Background: I plan to use lpmx.5 under cap power but need a way to save the rtc registers to FRAM when the super-cap runs down.
Plan: Use SYSRSTIV SVSH interrupt to wake up and save the counter, or ...
3
votes
1answer
116 views
Lithium thionyl chloride for GSM application
I'm trying o use a LiSoCl2 battery in a low power GSM application. When the system is in standby only the microcontroller(MSP430) is powered(3.3v) and the GSM(5v) and sensor(5v) is turned off. The ...
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0answers
61 views
Ultra low power battery
I am currently in the middle of a project and I am quite unsure of what type of battery and battery charger I should be using. To be honest I have never worked with battery or battery charger yet.
In ...
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2answers
99 views
Can transformerless power supplies be UL/CSA certified and is there any specific standard they must meet?
I am trying to bias a linear optocoupler on the AC mains side of a circuit, in order to transfer analog information to the secondary side of the circuit. I have designed the following capacitive power ...
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0answers
59 views
Ultra Low Power, LDO Enable from RTC vs. deep sleep MCU interupt
I have a question regarding optimising design for ultra low power consumption device. I'm trying to develop a remote sensor node that should measure and send data every few hours.
Currently I have an ...
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2answers
81 views
Low idle power consumption for USB PSU
I'm trying to find out how "good" 5V power adapters can be with respect to power consumption if:
there's no attached power consumer, and/or
the consumer takes very little power, such as an ESP32 in ...
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0answers
57 views
Measure low AC Power consumption (oscilloscope? MCU?)
I would like to measure AC power consumption of devices such as AC/DC charger, AC LED bulb or an electric circuit in the main box of a house.
However, their power consumption are quite low and the ...
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0answers
73 views
ESP8266-01S OFF State (CH_PD at LOW) Draining too much current
I have this project in which the life of the battery is imperative, after various designs i came up with this one:
As you can see the pushbutton labeled START puts the CH_PD pin on HIGH for a brief ...
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1answer
84 views
USB and coin cell battery switching
I'm trying to do a simple, low power, low cost power "switch" for a custom board (I know, it will be complicated).
The device will be powered by default by a coin cell battery (3V3 and lower) and can ...
