• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.


  1. H

    Home Project: Question on what motor to get for a battery-powered, motorized, high-speed 'lazy susan'

    Hi, I wonder if anyone could help me! In my project, I want to create a battery-powered motorized ‘lazy susan’, where the top part of wood will spin with an object on top. I am quite confident on how I will attach all the components to do this as there are many youtube tutorials on the internet...
  2. F

    What Type of Battery or Power Source Should I use For An Coil Gun

    I am making a coil gun with a classmate, and we are doing it as a home science project. We have the basic idea of how a coil gun works and how dangerous it can be, but we still are confused about what power supply we should buy. We want the power source to charge the capacitor bank for around...
  3. S

    Grid-tie Inverter vs Feed-In Inverter

    Hi all, New to the forum so please excuse the ignorance. I am looking to use a few second-life EV cells to make a home energy storage solution. I'm pretty comfortable with the more basic aspects of charging and battery management, but the inverter area I am finding a tad confusing. I would...
  4. N

    Motion triggered battery powered dimmable COB LED light

    My view on life, in any field, is not to produce more but to consume less. Everybody told me this is a very eccentric weird mentality. Perhaps they are right. Nevertheless I have to build my project to make a highly efficient, extremely low drain, motion triggered 12V battery powered dimmable...
  5. Q

    Troubleshooting an old tablet that has power supply issues

    Hi, I'm quite "new" to the world of electronics I have a CS background and I have a quite old tablet laying around that has power supply issues... it started randomly turning off so I used it with the charger plugged in for a while and now it doesn't turn on. I managed to start disassembling and...
  6. G

    Special development board

    Hello Currently the Grape-Express Mini development board is on Kickstarter. It's a microcontroller board like the Arduino Mega2560 R3, but this board includes a lot more than just Bluetooth, Wifi, and self-sufficiency. If there is interest, then look on the web page. The goal is not set high but...
  7. R

    Need help with wind turbine circuit

    Hello everyone, this is for my design project and i need help on a circuit regarding wind turbine. The turbine will be used on a fishing boat. Also, the turbine will power up a raspberry pi 3. Our only problem is hooking up the wind turbine to the raspberry pi. The load will be approx 10W. Our...
  8. J

    LED Lights and Timer all Battery Powered - HELP

    good morning, first post... I have a small project that i'm trying to accomplish and i'm am not very good at electronics, so I've come to all of you. Here's my goal; I"m trying to power (2) rolls of LED strip lights for 3 hours a day, solely by battery. The project will run in a display...
  9. A

    Can you help me with this power charger?

    I am on trip and now I am is small village where I can't buy anything soon. I need charging 4 AAA batteries. Battery have 750 mAh. I have this old charger from Germany. I have electricity 220 v. How many hours I need to charge to battery be full? Thank you in advance.
  10. J

    What voltage to apply to a 1.2V rechargeable battery?

    Hi there, I am just experimenting with a simple circuit that recharges 1.2V 3000mAh AA battery. But I have not idea what is the correct voltage to apply to the battery to recharge it. Do I need to apply 1.2 Volts? Maybe a little bit more? This circuit recharges the battery using induction, so...
  11. O

    Battery Charging

    Hi! I've been working on a project and I need it to be portable. So I have two batteries of PKCELL LP785060 it's a 3.7V 2500mAh battery. I connected the two in series which gives me a 7.4V battery. My question is, can I use the adafruit powerboost 1000C to charge these batteries connected in...
  12. J

    AAA NiMH Backup Battery Pack for 12V Automotive Use

    I have been asked to play a role in the design of a 12V backup battery pack that would be used to backup a vehicle security system and siren in exclusively AUTOMOTIVE applications. I have general electronics experience but no experience with the design of a battery backup system, and the...
  13. C

    Homemade Multi Drill

    Hi, I'm thinking of making a multi drill for wood drilling, that uses anywhere from 6 to 9 9V or 12V DC motors. These motors would be wired in parallel, with one battery source. I'd mount a drill chuck on each of the motors shafts for a drill bit. Now, I need a little bit of help from you. Do...
  14. C

    Solar Powered Electric Fence from electric fly swatter and garden lights

    Hey everyone, I'm working on a little project but circuit design isn't my area of expertise. I want to build a little electric fence to put around some potted plants and keep the squirrels away. There isn't an electrical outlet nearby, so I want to rely on solar power. I bought an electric fly...
  15. P

    Lithium Battery Low Voltage Failsafe.

    This is a project I’ve recently started working on. I’m trying to setup a LiFePo4 12V battery replacement for a normal lead acid car battery. Please note, this is NOT for an electric car, its for a normal Internal Combustion Engine Vehicle. I just want to replace the Lead Acid Battery with a...
  16. C

    Homemade Lithium ion battery bank questions

    Hello all, I'm new here. I'm seeking knowledge and advice about a Lithium ion battery bank that I made. I got these batteries from work out of a device that we replaced the batteries on. It is a somewhat proprietary battery as it is made specifically for this device and not open to the general...
  17. mading2018

    Lithium battery for a PHEV?

    Hello, I trying to find a equivalent battery model for a PHEV (plug-in-electric vehicle) and simulate the charing process in LTspice. I want the battery to have SOC=0, an empty battery from the begining, and starts to charge between the charging range of 320-380 V. I know the battery should...
  18. H

    Using Capacitors as Energy storage device - eliminating the phase differ between voltage & current

    I constantly read that capacitors provide reactive power. So how are they used instead of a battery? I mean in a battery the voltage and current are in the same phase. How is the phase change between the voltage and current in a capacitor eliminated without using an inductor, to use capacitor as...
  19. sr13579

    How to charge my 9V battery with a no load 5V output?

    I am pretty much new with this adapter thing. I bought an adapter today with a 9 V rechargable battery. I tried my multimeter between the output and found something interesting. The output voltage is 5 volts on the 9V port. But when I am connecting the battery and turning the adapter on the...
  20. S

    Victron centaur battery charger overcharging, please help diagnose and repair

    Hi there, I have a Victron Centaur battery charger, 12v 200 amp output. It's a monster! On inspection it's actually two identical 100a chargers in the same case, connected in parallel. Other than a tiny 3 wire cable whose purpose I'm not sure of, there is nothing connecting the two chargers...
  21. Vizier87

    Repairing a UPS backup power supply

    Hi guys, It's been a while. Before I actually buy a UPS backup supply, I need some advice and potentially save more than 50 dollars. I found one from a friend (APC ES 500). Naturally, it was already dead. I've hooked it up to the mains and no indicator LED or anything turned on. Dead as a...
  22. mheruian

    In-depth Battery Knowledge inquiry

    Hi, I'm new to electronics and I've been starting a project of my own which is a charger (since i though i should start first at power electronics since its all about electricity before pursuing switching electronics or automation). I had previously created a charging system (using the li-ion...
  23. Mosaic

    Desulfator Engine, Heavy duty, DIY, Overnight results.

    Hi all: I'm starting a Hackaday project to open source my proven desulfator engine. This is a pulse charge engine for batteries outside the vehicle as it delivers 250W RMS capability to the battery with up to 800A pulses...
  24. Gryphonn

    Using a 12 Volt Regulated Power Supply as a Battery Charger - Questions

    Hi folks I found this forum via a Google (is your friend0 search. I found some threads loosely related to my question, but nothing specific. Hopefully, some of you electrical/electronic aficionados may be able to assist. I have an old 'Transwest' brand Regulated Power Supply in good condition...
  25. A

    Sourcing surface mount high current connector

    Hi All I'm having a dilemna at the moment, I have designned a battery balancing circuit and need connector for this that are rated at 10A max per contact perivously I used a SAMTEC IPBT connector which met my requirement the only problem was the height with the connector and the mating half had...

EE World Online Articles