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Battery Chargers
All Battery Chargers:   #'s - B       C - K      L - R       S - Z

Also see:      Alkaline       Lead Acid        Lithium      Nickel

Last Updated: October 25, 2017 05:10 AM

Circuits Designed by Dave Johnson, P.E. :
LED_Light_8_Solar_Cell   -  I have been modifying a lot of solar garden and path lights for the last several years.  I buy some units from home improvement stores, then I gut them completely.  I take out the battery, electronic control board, LED and solar panel.  I then replace those components with new units.  I increase the size of the solar panel and battery.  I use a more efficient and brighter LED . . . Hobby Circuit by David Johnson P.E.-September 22, 2017

LED_Light_for_Tool_Shed   -  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. . . . Hobby Circuit by David Johnson P.E.-July 14, 2017

Light_Pathway_1w_Solar_Cob_LED   -  Chip on board (COB) LEDs are all the rage.  These devices assemble multiple tiny LED chips onto a metal backed circuit board, then cover the assembly with a plastic cover.  The metal back allows the assembly to be mounted to heat sink to keep the device cool.  The multiple LED chips can be wired into any number of series/parallel configurations.  Some are wired for 12v operation while other COB LEDs in flashlights are all wired in parallel, with an operating voltage of about 3 volts. . . . Hobby Circuit by David Johnson P.E.-May 23, 2017

Lighthouse_Solar_Powered   -  While at a discount store one day, I spotted an interesting tall lighthouse.  It had a tiny solar panel and an equally tiny LED light.  The LED was pointing downward, at the center of a rotating light reflector.  I thought it might be turned into an interesting addition to my wife’s garden. . . . Hobby Circuit by David Johnson P.E.-September 21, 2017

Lithium Battery Tester   -  I bought some lithium ion rechargeable batteries a while back.  I was planning on using them to modify some solar powered LED spot lights.  What I like about these new batteries is that they are the same size as a standard 1.5v alkaline AA cell . . . Hobby Circuit designed by Dave Johnson P.E.-February 05, 2012

Lithium Ion Solar Battery Charger-#2   -  A single lithium ion battery cell needs 4.2v from a current source to insure it is fully charged.    A solar panel with just enough individual cells wired in series to produce the needed voltage would be more efficient than one with more cells for a given surface area.    if you divide 4.2 by eight you come up with a figure of 0.525 volts . . . Hobby Circuit designed by Dave Johnson P.E.-May 21, 2013

Mason_Jar_Solar_Light   -  I have modified several commercial solar garden lights over the years.  I switch out the LED, solar panel, battery pack and control circuit.  The result is a much better overall light.  One of my disappointments in using store-bought garden light assemblies is their construction.  They are built so cheaply that over time, water and insects get inside, killing the light operation. . . . Hobby Circuit by David Johnson P.E.-September 21, 2017

Modified 4 D Cell LED Lantern   -  While shopping at a sporting goods store one day, I spotted a compact LED lantern.  It looked like the kind of lantern I could modify. The lantern LEDs were grouped into three sections of 7 LEDs each, oriented into 120 degree angles.  The LEDs were standard T 1-3/4 epoxy types.  The lantern had a three mode switch which selected between off, full power and half power modes.  At the half power mode, only half of the 21 LEDs were illuminated.  At full power all LEDs were illuminated. . . . Circuit by David Johnson P.E.-September 21, 2017

Modified Colman Lantern3   -  While shopping at a sporting goods store one day, I spotted a compact LED lantern.  It looked like the kind of lantern I could modify. The lantern LEDs were grouped into three sections of 7 LEDs each, oriented into 120 degree angles.  The LEDs were standard T 1-3/4 epoxy types.  The lantern had a three mode switch which selected between off, full power and half power modes.  At the half power mode, only half of the 21 LEDs were illuminated.  At full power all LEDs were illuminated. . . . Circuit by David Johnson P.E.-September 21, 2017


Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

L200 charger -  NOTE : Must register on this site __ Designed by Published in Elecktor July/Aug, 2010

Lead Acid Battery Charger -  Except for use as a normal Battery Charger, this circuit is perfect to 'constant-charge' a 12-Volt Lead-Acid Battery, like the one in your flight box, and keep it in optimum charged condition.  This circuit is not recommended for GELL-TYPE batteries since it draws to much current.  The above circuit is a precision voltage source, and contains a temperature sensor with a negative temperature __ Designed by Tony van Roon  VA3AVR

Lead Acid Battery Charger (Gell Cell) -  This high-performance circuit first quickly starts (Tony van Roon's and holds) the charge at 2 amp, but as the voltage rises the current will consequently decrease.  When the current falls below 150mA, the charger automatically switches to a lower 'Float' voltage to prevent overcharging.  At the point that a full charge is reached, Q1 will bias and the LED will light. __ Designed by Tony van Roon  VA3AVR

Lead Acid Battery Charger (LM317) -  The above pictured schematic diagram is just a standard constant current model with a added current limiter, consisting of Q1, R1, and R4.  The moment too much current is flowing biases Q1 and drops the output voltage.  The output voltage is: 1.2 x (P1+R2+R3) /R3 volt.  Current limiting kicks in when the current is about 0.6/R1 amp __ Designed by Tony van Roon  VA3AVR

Lead Acid Battery Charger with Float -  The circuit furnishes an initial charge voltage of 2.5 Volt-per-cell at 25°C to rapidly charge a Lead-Acid battery.  The charging current decreases as the battery charges, and when the current drops to about 180mA, the charging circuit reduces the output voltage to 2.35 Volt-per-cell, floating the battery in a fully charged state.  This lower voltage prevents the battery from overcharging, which would shorten its life.  The LM301A (Tony van Roon's U3) compares the voltage drop across R1 with an 18-mV reference set by R2.  The comparator's output controls the voltage regulator, forcing it to produce the lower float voltage when the battery-charging current passing __ Designed by Tony van Roon  VA3AVR

Lead-Acid Battery Charger with Voltage Analyser -  Nowadays maintenance-free lead-acid batteries are common in vehicles, inverters, and UPS systems.  If the battery is left in a poor state of charge, its useful life is shortened.  It also reduces __ Electronics Projects for You

Lead-Acid Charger Signals End Of Charge -  09/12/97 EDN-Design Ideas The lead-acid battery charger in Figure 1 works with either gel- or wet-cell, lead-acid, 12V batteries.  The charger includes the proper temperature compensation for the charger output voltage as well as a detector that signals when the battery is fully charged __ Circuit Design by Chester Simpson, National Semiconductor, Santa Clara, CA

Lead-Acid Low-Battery Detector with System Shutdown -  Resistor dividers are used to provide a signal comparison against a reference voltage.  The opamps operate as precision comparators to provide indications of battery charge state__ Linear Technology/Analog Devices App Note, Jun 21, 2010

LED_Light_8_Solar_Cell -  I have been modifying a lot of solar garden and path lights for the last several years.  I buy some units from home improvement stores, then I gut them completely.  I take out the battery, electronic control board, LED and solar panel.  I then replace those components with new units.  I increase the size of the solar panel and battery.  I use a more efficient and brighter LED . . . Hobby Circuit by David Johnson P.E.-September, 2017

LED_Light_for_Tool_Shed -  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. . . . Hobby Circuit by David Johnson P.E.-July, 2017

Light_Pathway_1w_Solar_Cob_LED -  Chip on board (COB) LEDs are all the rage.  These devices assemble multiple tiny LED chips onto a metal backed circuit board, then cover the assembly with a plastic cover.  The metal back allows the assembly to be mounted to heat sink to keep the device cool.  The multiple LED chips can be wired into any number of series/parallel configurations.  Some are wired for 12v operation while other COB LEDs in flashlights are all wired in parallel, with an operating voltage of about 3 volts. . . . Hobby Circuit by David Johnson P.E.-May, 2017

Li ion battery charger adapts to different chemistries -  09/02/99 EDN-Design Ideas Rechargeable lithium-ion (Li-on) cells require a precise charging voltage for maximum performance.  The battery chemistry, of which there are many, determines the optimum charge voltage.  Two of the more common charging voltages are 4.1V±50 mV and 4.2V±50 mV per cell. __ Circuit Design by Fran Hoffart, Linear Technology Corp, Milpitas, CA

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.

Li-Ion boost uses no inductors -  09/12/1997 EDN-Design Ideas To maintain a regulated 3.3V supply for portable applications, most Li-ion batteries require a low-dropout (LDO) regulator and a dc/dc boost circuit.  This need arises because the typical voltage range of a Li-ion battery is 4.2V (charged) to 2.5V (before recharge).  The regulator alone suffices in the battery range of 4.2 to 3.5V, but below that level, the battery voltage needs boosting to keep the LDO IC in regulation.  The circuit in Figure 1 senses the battery voltage via the R1-R2 resistor divider at comparator IC2.  The comparator turns off the converter when the battery voltage exceeds 3.6V. __ Circuit Design by John Parry and Bill McIntyre,National Semiconductor, Grass Valley, CA

Li-Ion CCD Bias Supply (15V,-8V) -  The LT3472 delivers up to –8V at 50mA and 15V at 20mA from a lithium-ion cell, providing bias for many popular CCD imagers __ Linear Technology/Analog Devices App Note, Mar 24, 2010

Li-Ion Charge Termination IC Interfaces with PWM Switchers -  DN242 Design Notes __ Linear Technology/Analog Devices

Li-ION Charge Termination using the LT1505 -  DN244 Design Notes __ Linear Technology/Analog Devices

Li-Ion Charger -  PIC Project  Lithium Ion batteries pack a lot of power by weight compared to other types.  There are 2 things that need to be handled differently than NiCad on NiMH
: __ Designed by Luhan Monat-Mesa Arizona

Li-Ion Charger -  The LP2951 regulator is manufactured by National Semiconductor.  The choice of values is from an App Note Battery Charging, written by Chester Simpson.  Diode D1 can be any diode from the 1N00x series, whichever is __ Designed by Izhar Fareed

Li-ION Linear Charger Allows Fast Full Current Charging While Limiting PC Board Temperature to 85°C -  DN283 Design Notes __ Linear Technology/Analog Devices

Li-Ion Powered Supply for CCD Imager & Five White Backlight LEDs -  The LT3587 provides a complete biasing solution for CCD (15V AT 50mA, -8V AT 100mA) and LED backlighting from a single Li-Ion cell __ Linear Technology/Analog Devices App Note, Mar 24, 2010

Li-Ion to +5V AT 25mA, +16V AT 1mA, –13V AT 1mA TFT LCD Power Supply + 10 White LEDs -  The LTC3524 is an integrated BIAS and white LED power converter solution for small/medium-sized polysilicon thin film transistor (TFT) liquid crystal (LCD) display panels__ Linear Technology/Analog Devices App Note, Mar 24, 2010

Li-Ion to Six White LEDs & OLED/LCD Bias -  The LT3498 can provide both the positive bias voltage required for OLED or CCD bias as well as drive multiple white LEDs for display backlighting__ Linear Technology/Analog Devices App Note, Mar 24th 2010

Li-Ion to Two White LEDs & OLED/LCD Bias -  The LT3498 can provide both the positive bias voltage required for OLED or CCD bias as well as drive multiple white LEDs for display backlighting__ Linear Technology/Analog Devices App Note, Mar 24th 2010

Li-Po Charger & Balancer -  This is a Li-Po charger and balancer project for R/C hobby.  The charger circuit is based on the circuit of Electron head and all folks in the DIY electronics topic on the rcgroups.  com.

Lighthouse_Solar_Powered -  While at a discount store one day, I spotted an interesting tall lighthouse.  It had a tiny solar panel and an equally tiny LED light.  The LED was pointing downward, at the center of a rotating light reflector.  I thought it might be turned into an interesting addition to my wife’s garden. . . . Hobby Circuit by David Johnson P.E.-September, 2017

Lithium Battery Tester -  I bought some lithium ion rechargeable batteries a while back.  I was planning on using them to modify some solar powered LED spot lights.  What I like about these new batteries is that they are the same size as a standard 1.5v alkaline AA cell . . . Hobby Circuit designed by Dave Johnson P.E.-February, 2012

Lithium Ion Battery Charger -  PIC Project  Lithium Ion batteries pack a lot of power by weight compared to other types.  There are 2 things that need to be handled differently than NiCad on NiMH
: __ Designed by Luhan Monat-Mesa Arizona

Lithium Ion Solar Battery Charger-#2 -  A single lithium ion battery cell needs 4.2v from a current source to insure it is fully charged.    A solar panel with just enough individual cells wired in series to produce the needed voltage would be more efficient than one with more cells for a given surface area.    If you divide 4.2 by eight you come up with a figure of 0.525 volts . . . Hobby Circuit designed by Dave Johnson P.E.-May, 2013

Lithium Ion, Lithium Poly Charger -  The above circuit will charge any 2-cell * Li-Ion battery pack.  Maximum current is about 650 milliamps.  The circuit is designed for batteries of 900mah or higher.  Note this circuit is NOT for Li-Metal batts (i.  e.  Duralites).  Power source can be a 12v Gell cell (Power panel) , or can be powered by a car's cigarette lighter.  I use an old 12v DC wall transformer (800ma or more.) Radio shack sells a 12v/1amp wall DC adapter #273-1776 that will work.  Supply does not need to be regulated.  In fact my cheap supply outputs 17 volts with no load.

Lithium-Ion Batteries 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

Lithium-Ion Charger, Single cell -  The LP2951 regulator is manufactured by National Semiconductors.  The choice of values is from an App Note "Battery Charging", written by Chester Simpson.  Diode D1 can be any diode from the 1N00x series, whichever is conveniently available.  It functions as a blocking diode, to prevent a back flow of current from the battery into the LP2951 when the input voltage is disconnected __ Designed by Tony van Roon  VA3AVR

Low Cost Thermal Peak Detection NiCd Charger -  The electric model aircraft and car industries have produced a bewildering array of field chargers for NiCd motor battery packs.  These range from simple 6 or 7 cell chargers consisting of a resistor and mechanical timer, to more complex chargers with peak detection, cycling, and the ability to handle 36 cell packs __ Designed by Stefan Vorkoettert

Low-battery voltage cutoff consumes just 1 mA -  09/11/98 EDN-Design Ideas NOTE : File has several circuits, please scroll to find this one.  A low-battery voltage-cutoff circuit prevents overdischarge of a rechargeable battery.  An obvious requirement of this circuit is extremely low power consumption.  Figure 1a's simple circuit has a measured current consumption of approximately 1.2 mA and uses only two __ Circuit Design by Yongping Xia, Teldata Inc, Los Angeles, CA

Low-Cost Battery Charger -  Here is a very simple and low-cost charger for 12V, 7Ah lead-acid batteries.  It can also be used for powering automobile engines and emergency lighting systems.  As shown in the figure, diodes __ Electronics Projects for You

LT1510 High Efficiency Lithium-Ion Battery Charger -  DN111 Design Notes__ Linear Technology/Analog Devices

LT1511 Low Dropout Constant-Current/Constant-Voltage 3a Battery Charger -  DN144 Design Notes__ Linear Technology/Analog Devices

LTC Design Note: Monolithic linear battery charger operates from inputs up to 60V -  EDN-Design Ideas 03/31/2016    For lower current, keep-alive battery charging, a simple yet richly featured linear solution can be Ideasl __ Circuit Design 

Make a Constant Current NiCad Charger -  The schematic for this charger is pretty simple.  You can charge from 1 to 20 +/- nicads at a constant current of from 20 to 200 ma +/-.   The circuit I modified from an article in July 1977 “73 Amateur Radio Magazine.” __ Designed by Pete Christensen

Make a Simple Circuit PC-Based frequency meter  -  04/29/99  EDN-Design Ideas –  NOTE :  Scroll to find this circuit.   A simple, low cost, and precision frequency meter uses only two pins of a pc parallel port (Figure 1). The TTL-level periodic input signal with frequency fIN connects to the ACK pin of LPT1. __ Circuit Design by Radovan Stojanovic, University of Patras, Patras, Greece

Mason_Jar_Solar_Light -  I have modified several commercial solar garden lights over the years.  I switch out the LED, solar panel, battery pack and control circuit.  The result is a much better overall light.  One of my disappointments in using store-bought garden light assemblies is their construction.  They are built so cheaply that over time, water and insects get inside, killing the light operation. . . . Hobby Circuit by David Johnson P.E.-September, 2017

Minature Low Dropout Battery Charger for Lithium-Ion Batteries -  DN239 Design Notes __ Linear Technology/Analog Devices

Mini Mill Battery Charger -  Taking about 30 minutes to make from old computer parts, the Mini Mill will can charge a couple of NiCad batteries. __ Designed by Flavio Dellepiane

Mobile Cellphone Charger -  Charging of the cellphone battery is a big problem while travelling as power supply source is not generally accessible.  If you keep your cellphone switched on continuously, its battery will go __ Electronics Projects for You

Mobile Charging With Heat Using A Teg Module -  This circuit can come in handy when you are camping in a remote area where there is no electricity available to charge your mobile phone’s or tablet’s battery. If you can __ Electronics Projects for You

Mobile Phone Battery Charger -  Mobile phone chargers available in the market are quite expensive.  The circuit presented here comes as a low-cost alternative to charge mobile telephones/battery packs with a rating of 7.2 volts, such __ Electronics Projects for You

Mobile Phone Multipower Unit -  Most of the mobile phone complaints are related to the power supply.  This is mainly because of improper charging and use of non-recommended chargers and low-quality batteries.  Depending upon the make __ Electronics Projects for You

Modified 4 D Cell LED Lantern -  While shopping at a sporting goods store one day, I spotted a compact LED lantern.  It looked like the kind of lantern I could modify. The lantern LEDs were grouped into three sections of 7 LEDs each, oriented into 120 degree angles.  The LEDs were standard T 1-3/4 epoxy types.  The lantern had a three mode switch which selected between off, full power and half power modes.  At the half power mode, only half of the 21 LEDs were illuminated.  At full power all LEDs were illuminated. . . . Circuit by David Johnson P.E.-September, 2017

Modified Colman Lantern3 -  While shopping at a sporting goods store one day, I spotted a compact LED lantern.  It looked like the kind of lantern I could modify. The lantern LEDs were grouped into three sections of 7 LEDs each, oriented into 120 degree angles.  The LEDs were standard T 1-3/4 epoxy types.  The lantern had a three mode switch which selected between off, full power and half power modes.  At the half power mode, only half of the 21 LEDs were illuminated.  At full power all LEDs were illuminated. . . . Circuit by David Johnson P.E.-September, 2017

Monolithic linear battery charger operates from inputs up to 60V -  EDN-Design Ideas 03/31/2016    For lower current, keep-alive battery charging, a simple yet richly featured linear solution can be Ideasl __ Circuit Design by LTC Design Note

Motor Accu Lader -  Article is in Dutch __ Designed by Jan Hammer

Motor AccuLader -  Dutch Language B.J.G. Hamermaart

Motorbike Battery Charger -  ideal to enhance any scalectrix race track __ Contact: P. Townshend EduTek Ltd

Multi NiCad Charger -  This unit was constructed in the shell of a Radio Shack battery charger.  The original unit charged only one type of battery at a time and only in pairs.  This unit allows for mix and match for AAA, AA, C, and D cells.  Each battery is individually monitored and charged.  An LED for each one flashes to show the current charging condition as follows __ Designed by Luhan MonatMesa Arizona

Multicell Charger -  Using this charger, you can safely charge up to two pieces of Ni-Cd cells or Ni-MH cells.  The circuit is compact, inexpensive and easy-to-use.  The 230V AC mains is down-converted to 12V __ Electronics Projects for You

Multifunction Power Supply -  Many embedded systems these days need +5V power supply with some special functions such as power-fail detection, zero-crossing signals for mains power supply and possibility to maintain the charging of built-in __ Electronics Projects for You

Muscle power drives battery-free Electronics -  11/21/05  EDN-Design Ideas Your sweat and a super-cap replace the battery __ Circuit Design by Alexander Bell, Infosoft International Inc, Rego Park, NY

      >>>

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