Voltage regulation for NodeMcu
I am trying to develop a custom PCB with the esp12-E module. For development and testing, I am using the nodemcu development board ESP8266 V3. I am powering the nodemcu via a 3.7V battery with a...
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ESP32 power efficient battery monitoring
I'm trying to implement a simple battery monitoring circuit for an ESP32 that gets completely shut down and then powered on periodically. I don't want to drain the battery and/or backpower the ESP32...
View ArticleWhat is the cost of converting 12V (lead acid battery) to 220V and back again...
I have a small house measuring ~ 8m x 4.5m. It is in Indonesia and power outages are expected daily. Probably the daily power outage is on average less than half-an-hour, but sometimes the outage can...
View ArticleBuilding a battery powered computer system
I want to power a PC, monitor and modem with one deep cycle 12 V lead-acid battery.The PC is a mini-ITX board with intel N100 CPU. It consumes between 10-40 W depending on usage and has a 19V DC power...
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Repair wiring of ATR6550 Condensor Microphone with 3.5mm Jack
I own a ATR6550Condensor Shotgun Microphone in which at some point before going to my university i forgot a battery at it leaked causing corrosion on connections in battery Section and some broke...
View ArticleResistor value to minimize current drawn from battery in an Arduino project
My Arduino project (Pro Mini, two sensors, BT09 BLE module) is powered by a PG1050 3.7V battery via a boost converter that raises the voltage to 5V. To measure the battery and report low battery status...
View ArticlePower issues with Nodemcu and Sim800L
I am building a project and i am facing weird anomalies while implementing it. Keep in mind in a student a fairly new to this. So the problem is that i have a usb- charging module connected with a...
View ArticleAm I doing something dangerous with an AC to DC power supply?
I am new to electronics, and want to check to make sure I'm not missing critical points of safety, or setting myself up to do something stupid/dangerous.The project I'd like to build is a compact...
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Alternate power supply for dashcam, with latching relay
I am trying to setup dashcam with a dedicated battery for my car, I have a crude diagram to explain my logic. Yet to figure out detailed specs.The dashcam will run as usual car's ignition power, when...
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My MQ6 gas detector stops working properly after some time when using a battery
I've connected an MQ6 gas sensor to the output of a 78L05 5 V regulator, with its input connected to the + terminal of a Duracell 9 V battery. The DOUT pin of the MQ6 is connected to the - terminal of...
View ArticleIs my PCB shorting to ground?
I am working on a senior design project that utilizes a 3.7V lithium ion battery. Before I connect to the board, the pins show 3.7V (as expected). When I plug the battery into the connector, measure...
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Problem with battery power circuit
I am a 14 years old boy and I am currently making a MacroPad with a 3.7V battery and a charging circuit but powering the circuit with a battery does not seem to work. I also have made some modification...
View ArticleWhere to connect shielded cable when you have no chassis?
I joined a project after some of the initial design decisions were made, so it’s not quite how I’d like it, which now presents me with a bit of a problem.I have two power cables that are emitting...
View ArticleIncrease current draw of a low-voltage DC fan circuit
I have a DC fan circuit that is intended to run off of a portable USB battery pack. The fan is a 5V brushless computer fan that draws approximately 250mA. The issue I am running into is that all the...
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Powering vibrator for clearing vacuum cleaner filter
I've found that one easy way of clearing the corrugated filter in many vacuum cleaners is to tap it lightly with a hammer. I suspect that using a vibrator would be more effective, and I would like to...
View ArticleWhat type of memory should I use in a temperature datalogger with battery?
I'm designing a temperature data logger that will operate with a CR2032 battery, but I'm unsure what storage device would be good to use in this application. I would like to have capacities greater...
View ArticleESP8266 reduce power consumption caused by extra ICs/components on board...
I need to reduce the power consumed by a circuit based on ESP8266 and extra circuitry (I2C sensors, light resistor based sensor, etc.). By now when I set ESP8266 in deep sleep I still have a relevant...
View ArticleLooking for an extremely low power RTC module (and more!)
I'm working on a project called The Fifty Year Beep. The goal is to produce a battery-powered circuit that will beep once and only once fifty years from now. It is an art project of a kind, inspired to...
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Low power consumption/leakage tips and tricks (input NC magnetic reed switches)
I have an ATtiny412 that has 2 pins (PA1, PA2) set as internal input pullups.These 2 pins (PA1, PA2) sense magnetic reed switches with the NC setting. GND is active when closed on these switches.The...
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Powering a Raspberry Pi Zero with a Li-po battery
I want to design a circuit to power a Raspberry Pi Zero using a single-cell Li-po battery (3.7 V).I'm working on a portable hobby project that's required to be battery powered and allows recharging the...
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NiMH battery pack charging circuit using a solar panel
I have been working on a NiMH battery pack (7.2V / 2100mAh) charging circuit powered by a 12V solar panel. With some research I found that charging NiMH takes different forms by measuring change in...
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Emergency backup battery supply
I am building a NodeMCU-controlled 12 V solenoid. I am hoping to add an emergency backup battery supply, but the emergency backup supply should not power anything but the solenoid. In other words, if...
View ArticleBattery-powered device: trade off between voltage and power requirements
I'm designing a device that would be powered (LiPo I guess) by rechargeable batteries. They will be charged externally.The power requirements are the following:the load runs at 12 V (pump and few...
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Is it possible to draw 12V from both halves of a 24V battery pack?
Firstly, I am fully aware of buck converters.This question is all about the possibility of my imagination.I have a 24V battery pack, powering one 24V device.Because I am able to tap into the middle of...
View ArticleCan I connect homemade battery packs in parallel?
I'm working on batteries to run an underwater drone and a follow-boat using 3.7 V, 3400 mAh Li-ion cells. I need a voltage of around 18.5 V and around 20 Ah.The thought-up solution was to make several...
View ArticleWhat's the best way to make sure I have a known VCC on a battery powered device?
I'm making a portable device (well not really portable, but intended to be set up away from mains power) powered by AA batteries. I need a stable VCC as I have displays that I don't want the brightness...
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PIR Sensor Interference When RF Transmitting
I have created a small DIY circuit which sends a signal over 433.92Mhz when a PIR sensor is triggered.The circuit consists of 4 modules soldered onto stripboard.Schematic:Components are:0.71mm tinned...
View ArticleBattery size needed for a submersible pump
I bought a small solar fountain pump which does not work well on cloudy and monsoon days. So I want to hook this pump on to a battery which I am considering to recharge once in a month. The pump has no...
View ArticleLED : Efficiency vs Forward Current (rather than Light Intensity vs Input...
LED CharacteristicsLED datasheets commonly provide:\$ I_{v}\ [cd] \$ Light Intensity vs \$ I_{f}\ [A] \$ Forward Current\$ V_{f}\ [V] \$ Forward Voltage vs \$ I_{f}\ [A] \$ Forward Current(Often, the...
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Is it possible?? Battery adapter for Hoover OnePWR [closed]
I'm beyond my knowledge base and really need some guidance. This Hoover OnePWR cordless stick vacuum still works great and I truly don't want to trash it. However, the batteries for these are terrible;...
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