|Three Fake Alarms - Battery Powered LED Circuits: Flashing LEDs can be used to create the impression that an alarm has been fitted. Or they can be used in conjunction with a real alarm to warn-off a potential thief. These three small circuits will flash anything from a single LED up to 90 LEDs and beyond with a variety of speeds and patterns. __ Designed by Ron J.
Tool Shed LED Light - I have a lean-to 8ft by 12ft shed next to my house. It is full of lawn chemicals and garden supplies. There were times when I needed to get something from inside the shed during the dead of night. Early on I had to use a flashlight. But later, I installed a series of five 12v LED light strips on the ceiling. Each strip contained 15 3v white LEDs. The strip had 5 strings of three LEDs, wired in series, with a 150 ohm current limiting resistor. . . . Circuit by David Johnson P.E.-July, 2017
Travel Charger - Charge USB appliances without a PC.
U-131 Simple Circuit Switchmode Lead-Acid Battery Charger - U-131 APPLICATION NOTE
. The charger circuit implements a two loop control. system with the current loop operating inside the. voltage loop. During trickle-charge, bulk-charge and|
Charger - Sometimes its more convenient to recharge batteries 'in place' rather than removing them and putting them in an external charger. This device is built around a PIC12F675 (a dandy little part from Microchip). The number of cells (1 to 8) is programmed in using the one button __ Designed by Luhan Monat-Mesa Arizona
USB Li-Ion Battery Charger - This is a charger for lithium ion batteries which takes its power from the USB port of a computer. It uses the MCP73861 or MCP73863 Li-ion battery charger chip manufactured by Microchip. Microchip MCP73861 or MCP73863 are advanced, fully-integrated, single-cell Li-Ion/Li-Polymer charge-management devices allow these peripherals to utilize the full power of the USB port.
USB Powered AA NiMH
& NiCd Battery Charger - The charger in this project is designed to charge two AA NiMH
or NiCd cells of any capacity (as long as they are the same) at about 470mA. It will charge 700mAh NiCds in about 1.5 hours, 1500mAh NiMH
s. __ Designed by Stefan Vorketter
USB-Powered Lithium-Ion Battery Charger - With a maximum power rating 5.25V/500 mA, the USB power bus is a great source for charging a single-cell Lithium-Ion battery. The circuit in Figure 1 shows how to build a USB-powered single-cell Li-Ion battery charger using National Semiconductor s LM3622 Li-Ion Battery Charger Controller.
Versatile Battery Charger - This transformer-based battery charger circuit can be used to charge any battery, provided the transformer rating is higher than the battery rating. __ Electronics Projects for You
Very Low Cost SOT-23 Li-ION Battery Charger Requires Little Area & FeW Components - DN250 Design Notes __ Linear Technology/Analog Devices
Voltage Monitor Prevents Deep Discharge of Battery - 09/26/96 EDN-Design Ideas To avoid the deep discharge that can destroy or shorten the life of a rechargeable battery, you must disconnect its load before the discharge is complete __ Circuit Design by Ron Clark and Larry Suppan, Maxim Integrated Products
Voltage Monitor with LED indicator - This project is an accelerometer data acquisition system for automotive suspension analysis. In other words it’s a low frequency spectrum analyzer based on Lanchpad TIVA Series from Texas Semiconductors.|
White LED-Based Emergency Lamp & Turning Indicator - White LEDs are replacing the conventional incandescent and fluorescent bulbs due to their high power efficiency and low operating voltage. These can be utilised optimally for emergency lamp and vehicle turning __ Electronics Projects for You
Wind Generator Dump LoA - D - The enclosure above contains a wind generator dump load. It was designed to be mounted at a remote repeater site where the source of power is a wind generator. When the battery is fully charged the voltage on the terminals will reach 14.1V. At this|
Zap Adapter - Don't throw away those seemingly un-chargeable, rechargeable batteries; they could very well be brought back to life with the aid of this simple circuit. (Tony van Roon's Tony van Roon) __ Designed by Tony van Roon VA3AVR
Zener regulator - A 13 volt Zener diode will work well for charging a 12 volt battery on Standby use. Or use a 14 volt zener a diode for a Standard 14.6 volt charge. __ Designed by G.L. Chemelec