With Instructables you can share what you make with the world, and tap into an ever-growing community of creative experts.
Welding Gloves That Live Forever
Solar Water Heater from scratch
Garden hose adapter for IBC...View Instructable »
By the way, for certain values of the variable resistor, this Dell power supply will shut down it's output and will not turn it on again unless you disconnected it from the mains (in advance you need to rotate the variable resistor to a suitable value). For sure it was designed to provide a fixed voltage with a good efficiency and maybe a modification of + / - 4 Volts can be ok, but to have a nice variable power supply, not really. But for such mods, BeachsideHank made a useful comment about using a linear regulator :) (I think there are as well Instructables on this)
Thank you for your feedback! I wanted to check for myself the formula (on this Dell power supply it is Vout = 2.5 x (R41 + R42||R42A) / (R42||R42A) ). I used values of the resistors on board (see my schematic from the Instructable) and the output voltage (19,5 Volt), I expected to calculate 2.5 Volt from the voltage divider at the VSENSE pin, since this will be compared with the internal 2.5 Volt reference. (R42 || R42A = 1996 Ohm). Voltage divider output (R41 and R42||R42A) for 19.5 Volt input is 0.556 Volt. For a certain frequency, R41 is parallel with R41A, in that situation divider output is 17,17 Volt. Not sure why.
Thank you for your feedback!
Thanks for your feedback! This effort was mostly on mechanical side, on the electronics was less effort. I think this was the reason: somewhere on the circuit I have only to replace a single resistor without considering the mechanical part of the project. This modified power supply will serve my Lithium charger only and can supply around 4 Amps max, while linear regulators can supply less current, have voltage drop on them, need extra heat sink, need a case too. I used a linear regulator for a bench power supply.
Modify a Dell laptop power ...View Instructable »
Thanks for your feedback, it may work what you are saying. You can provide the correct voltage using 5 volt USB and a regular diode and using the USB charger you should be able to give a certain amount of current. Also you need to keep an eye on a clock, divide battery capacity to the current provided by USB charger to see how much time is needed to let it charge. One I'll experiment this:)
Thanks for your feedback, I agree about lipos from ebay, you can pay a few dollars for a 6000 mAh :) I use recovered 18650 from laptop batteries. Regarding the electronics I used, that micro USB module may fail as well, but I trust it since I am using this for a while and on the other hand the voltage is lower.
Thank you for your feedback :)
Thank you for your feedback, I added an important-missing link - there is an youtube video and there you can find a good explanation on how this module work. Basically it will take care on the Lithium cell (single cell), it will charge it and will discharge it on the given specs of the Lithium.
Simple RC Stick Plane Build(CAD Model Included)
What is the exact damage done to the board? I am not sure that I understood what is fixing your method. Initially I thought that you had an overvoltage and damaged the micro and the only way is to replace it :)
Liquid Level Capacitive Sensor
Interactive Menus for your project with a Display and an Encoder
Micro USB Lithium charger f...View Instructable »
Pallet hammock stand
FreeRTOS 01 : Setting Up FreeRTOS on Arduino
Introducing LoRa™ !
Arduino LoRa Sensor With InAir9B Radio
Arduino Project: Test Range LoRa Module RF1276 for GPS Tracking Solution
How to make an Universal DC Motor Speed Controller
Old PC Recycled Regulable Power Supply
Wi-Servo: Wi-fi browser controlled servomotors (with Arduino + ESP8266)
Triple Your Tool Storage Space!
Making Simple PVC Flutes
PVC "Mouse Ear" Tool Clips
Make a Wood Carrier that's a Cinch
Mini weather station with Attiny85
15 Projects for Raising Backyard Chickens
Building a 3D Printer Under 200$
CNC Plasma Table
Nail Bottle Opener
Raspberry Pi. Create your first Connected Light
Complete DIY Raspberry Pi Weather Station with Software
DIY Arduino controlled Egg-Bot
Arduino Load Cell / Scale
Raspberry Pi: Completely Wireless IP Camera. Solar Battery Pack, WiFi, Logitech Camera, Raspbian
Stand alone video surveillance system with Raspberry Pi
Raspberry Pi Motion Sensitive Camera
How to make a cheap Attiny Arduino Board
Portable Bluetooth Speaker 2x3W Finished !
Build a 30$ laser Scanner
Mini Arduino CNC
OpenVR - 3D printed Rift for only 150$
Solar Water Pump
Melt your Beeswax with the Sun
External beehive protection and insulation for national hives
Track Honeybees With Temperature
Sugar Coated Honey Bees -or- How To Test for Varroa Mites
Honey Bee Counter
Raspberry Pi Portable Games Console
Raspberry Pi Solar Weather Station
Raspberry Pi Compact Camera
3D Printed Desktop CNC mill
Old PC Accessories + Raspberry PI = DoorCam & surveillance Kit **updated 2016**
Super great A-frame rabbit hutch!
DIY tablet: Powerful, Easy-to-make, (relatively) cheap [Part 1: the guts]
Internet Controlled Arduino (no Ethernet shield)
Raspberry Pi Shutdown Button
DIY solar cell from scratch
Cheap and Easy Solar Heater
The BEST Homemade Cough Syrup EVER
Fire Tubes - Original and New Compartment Design
DIY sharpening system from a broken breadmaker
ARDUINO MPPT SOLAR CHARGE CONTROLLER (Version-3.0)
My Money-Saving Habits
Perfect Restaurant Quality French Fries
Pier 9 Guide: Beginner and Advanced CAM Programming
Obstacle avoiding robot
How To Make An Amazing Physics Toy With 3 Balls & A String
How to make a reliable motorcycle voltage regulator
Coconut Almond Energy Bars
Stop using Ferric Chloride etchant! (A better etching solution.)
Join 2 million + to receive instant DIY inspiration in your inbox.
© 2016 Autodesk, Inc.