Inductance meter for RF Inductors - needed a way to measure hand-wound RF inductors in my second lab, and since I would only be doing this occasionally, I didn't need anything fancy, and since once a friend finishes his AT90S1200-based design, I plan to make one myself, I figured I'd use this for less than a year, so I didn't want to invest __ Designed by Dick Cappels In-Situ Battery Test Probe - This item describes a simple probe that allows in-situ AA and AAA battery voltage and current drain measurements without removing the cells from the holder. In use, the probe is simply pushed between the positive end of one cell and either the negative end of the adjacent cell or the battery holder terminal. The probe [?]|
LC Determination by Resonant Frequency Measurement ATtiny2313, AT90S2313 - A well known L/C measurement circuit is pressed into service to make a bare bones measurement circuit. __ Designed by Dick Cappels
Lead-Acid Battery Low Voltage Indicator - Lead-acid batteries should not be discharged below a certain voltage. Discharging a cell below about 1.8v and can often damage it, which will result in a lower amp-hour capacity. Large battery banks are critical in off-grid energy storage systems. One. . . Circuit by David A. Johnson P.E.-July, 2006
Lead-Acid Battery Monitor - This mini-project came about from building a garden shed. I decided to re-purpose an old UPS battery along with some spare halogen downlighters for illumination. But as I researched lead-acid technology, I decided that I needed something rather more sophisticated than a simple switch if I wanted the batteries to survive __ Designed by Mark Hennessy
LED 12 Volt Lead Acid Battery Meter - In the circuit above, a quad voltage comparator (LM339) is used as a simple bar graph meter to indicate the charge condition of a 12 volt, lead acid battery. A 5 volt reference voltage is connected|
LED Battery Condition Indicator - In the circuit below, a quad voltage comparator (LM339) is used as a simple bar graph meter to indicate the charge condition of a 12 volt, lead acid battery. A 5 volt reference voltage is connected to each of the (+) inputs of the four comparators and the (-) inputs are connected to successive points along a voltage divider. The LEDs __ Designed by Bill Bowden
LED Flasher Indicates Low Battery Condition - 01/02/97 EDN-Design Ideas Many portable electronic devices could benefit from a visual indication when their battery requires replacement. Typical low-battery indicators simply turn on an LED when the battery voltage drops below a certain value. Such circuits actually accelerate the battery's extinction by drawing excessive current. The circuit in Figure 1 draws a mere 1 m A in its standby mode and averages only 20 m A when activated. The low current imposes a minimal burden on any battery circuit. An off-the-shelf, undervoltage sensor IC(IC1) monitors the battery voltage-- __ Circuit Design by David Johnson, DiscoverCircuits.com
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 David A. Johnson P.E.-February, 2012
Lithium Ion Battery Stack Monitor with Both Signal & Power Isolation - Software to communicate with the EVAL-CED1Z and AD7280A is provided with the AD7280A evaluation board package. Connection between the EVAL-CED1Z and the USB port of a PC is via a standard USB 2.0 connection cable that is provided as part of the EVAL-CED1Z package. , Getting Started Complete details of setting up the hardware and installing the software are contained in UG-252__ Analog Devices from the Lab
Little More Serious Frequency Meter/CounterATtiny2313, AT90S2313 - Maximum input frequency is specified to be 30 MHz in the multi-chip configuration, and in single-chip configuration, there are both 5 MHz and 10 Mhz versions operating with 10 and 20 MHz crystals, respectively. All versions have 9 1/2 digit resolution. I haveused __ Designed by Dick Cappels
LM3914 Battery Monitor - This circuit should be powered by its own battery, otherwise you might get an innacurate reading. hook the to-be-monitored battery to pin 5 of the chip. __ Designed by Andy Wilson
Low battery cut-off for a car or truck - Also acts as a Master On / Off Switch. NOW, Also a New P-Mos Version. Supplies Positive voltage to grounded devices. __ Designed by G.L. Chemelec
Low Battery Indicator - File contains several designs, please scroll to find this circuit. Here is a low battery indicator that flashes a lamp when the battery voltage falls below about 5 volts. The circuit draws about 25 microamps when not flashing so battery life is not significantly shortened by the circuit. The two 1 megohm resistors set the switching point at V/2 (plus a little due to the emitter-base diode drop) and when this voltage is above the zener voltage the circuit cannot turn on. When the battery voltage drops below 5 volts, the base voltage drops to 2.5 volts and the emitter can reach a voltage sufficient to turn on the PNP (2N4403 or similar). When the PNP conducts, the NPN also conducts dropping the voltage across the circuit even more and the circuit snaps on. When the 4.7 uF capacitor has discharged, the circuit turns off and the capacitor begins charging again. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Low Battery Indicator Ii - This circuit indicates the remaining battery life bAy varying the duty cycle and flash rate of an LED as the battery voltage decreases. In fact, the circuit actually indicates five battery conditions: (1) a steady glow assures indicates that the battery is healthy; (2) a 2Hz flicker (briefly off) indicates that the battery is starting|
Low Battery Monitor Delays System Shutdown - App Note #134__ Maxim Integrated
Low Battery Voltage Flasher - This circuit is designed to monitor two alkaline cells (3v) that form the battery often used in portable electronic equipment. . . Circuit by David Johnson P.E.-January, 1998
Low Voltage Battery Disconnects - Find out more about low voltage battery disconnect (LVD) circuitsused to protect batteries. __ Designed by REUK-Renewable Energy UK website
Low Voltage Indicator for Lead-Acid Battery - Lead-acid batteries should not be discharged below a certain voltage. Discharging a cell below about 1.8v and can often damage it, which will result in a lower amp-hour capacity. Large battery banks are critical in off-grid energy storage systems. One . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2006
Low-Battery Detector Preregulates Input Voltage - 08/15/96 EDN-Design Ideas The circuit in Figure 1 uses the comparator and voltage reference of a low-battery detector to preregulate the input voltage. The circuit provIdeas an additional regulated voltage output at VOUT1 and significantly reduces the linear regulator's (VOUT2's) power dissipation. The two outputs (12V at 50 mA and 5V at 100 mA) are independent. __ Circuit Design by Khy Vijeh, Analog Devices Inc, Santa Clara, CA
Low-Battery Indicator has High-Efficiency - 05/03/01 EDN-Design Ideas The usual method for implementing the low-battery warning featured in most battery-operated equipment is to illuminate an LED. However, the LED exacerbates the low-battery condition. You can greatly reduce the LED's power consumption by operating it at a low frequency and a low duty cycle. __ Circuit Design by Joe Neubauer
Low-Battery Indicator Uses Fleapower - 4-Sep-03 EDN-Design Ideas It is always desirable to use a low-battery indicator that consumes as little power as possible. For a 9V, 450-mAhr alkaline battery, a 50-?A low-battery indicator can by itself run the battery down in a littlethan a year. Battery-powered devices that need to run continuously for a long time require battery indicators that consume minimal power __ Circuit Design by Yongping Xia, Navcom Technology, Redondo Beach, CA
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 active load draws constant battery power - 04/13/00 EDN-Design Ideas Unlike nickel-metal-hydride and lithium-ion rechargeable batteries, the discharge voltage of alkaline batteries is not constant and tends to vary from 1.5 to 0.8V per cell. Alkaline-battery manufacturers specify the discharge life of their batteries under constant powerloads. Because of the varying discharge voltage, you can't simply connect a load resistor to the cells to verify or measure power profiles without incurring a lot of error in your measurements. The circuit in Figure 1draws a constant power from the battery pack. Thus, as the battery voltage decreases, the load current increases. A single potentiometer allows a user to set the desired wattage draw. The circuit is simple and inexpensive to build. __ Circuit Design by Doug Farra
LT1304: Micropower DC/DC Converter with Independent Low-Battery Detector - DN120 Design Notes__ Linear Technology/Analog Devices |