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Circuit provides reverse-battery protection - 12/21/00 EDN Design Ideas: A universal problem in battery-operated devices is the threat of damage when an end user (never an engineer) inserts the battery backward. You can avoid damage by inserting a single diode or by using a diode-bridge configuration, but those fixes waste power and reduce the supply voltage by adding one or two diode drops between the battery and the supply rail. An alternative solution not only protects against battery-reversal damage, but also automatically corrects the reversal (Figure 1). Design by John Guy, Maxim Integrated Products, Sunnyvale, CA
Circuit Safely Deep Discharges NiCd Battery - NIC d batteries possess an undesirable memory effect caused by partial discharges. The remedy is to do a complete discharge before charging again. Figure 1 shows a simple circuit which performs this feat. Although relatively straightforward in concept, the circuit has three redeeming features: 1) it is powered by the battery being discharged.2) After the battery is fully discharged current drain is only about 4 uA, usually well below the self-discharge of a battery alone.3) Near end-of-charge the LED flashes.9publised 04/29/99 EDN-Design idea) __ Designed by Jim Hagerman, Science & Technology International, Honolulu, HI
Circuit safely Deep-discharges NiCd battery - 04/29/99 EDN-Design ideas – NOTE: Scroll to find this circuit. Nickel-cadmium (NIC d) batteries can possess an undesirable memory effect due to partial discharges. The remedy is a complete discharge before charging again. Figure 1a shows a simple circuit that performs this feat. Design by Jim Hagerman, Science & Technology International, Honolulu, HI
Circuit Secures Bootstrap Operation Under Light Load - 05/12/11 EDN Design Ideas: Additional circuit lets a capacitor charge, preventing voltage dips. A previous Design idea highlights a potential issue of a bootstrap IC under light-load or prechargedload operation (Reference 1). The circuit in Figure 1, with the additional circuit in the green box, fixes the problem of a voltage dip in the bus-voltage signal. The waveforms in Figure 2 demonstrate how this problem takes place in buck converter IC 1B when its output voltage, VBUS, dips below the regulation point at a fixed rate under no load. By inspecting the other traces in Figure 2, you can conclude that the dip of VBUS occurs Design by Chee H How, Kuala Lumpur, Malaysia
Circuit-breaker handles voltages to 32V - 25-May-00 EDN Design Ideas: The simplicity of low-side current monitoring can mask the advantages of a high-side approach. You can monitor load currents in a power supply, a motor driver, or another power circuit on either the high or the low side (ground]. However, don't let the ease of low-side monitoring cause you to overlook Design by Greg Sutterlin and Craig Gestler, Maxim Integrated Products, Sunnyvale, CA
Complete 12V Automotive Undervoltage, Overvoltage & Reverse-Supply Protection - The LTC4365 is a unique solution that elegantly and robustly protects sensitive circuits from unpredictably high or negative supply voltages. The LTC4365 blocks positive voltages as high as 60V and negative voltages as low as –40V. Only voltages in the safe operating supply range are passed along to the load. The only external__ Linear Technology/Analog Devices App Note, Sep 19th 2011
Current Limit Protects Power Bus - 12/12/97 EDN Design Ideas: Protects a power bus from a load short within a guaranteed2 µsec response Time Design by Ron Lenk, Temic/Siliconix, Santa Clara, CA
Current limiter provides latch-up signal - 01/01/98 EDN Design Ideas: Current-limiting circuit both signals a latch-up condition and prevents latch-up-induced overcurrent destruction of a CMOS
IC or group of IC
Design by Hartmut Henkel, von Hoerner & Sulger GmbH, Schwetzingen, Germany
Data acquisition system uses fault protection - 04/15/04 EDN Design Ideas: ensitive systems, such as those in aircraft, must withstand fault conditions, thereby avoiding component and system damage, because a sensor failure could cause a catastrophic event to occur. A channel protector, comprising two n- Design by Catherine Redmond, Analog Devices, Limerick, Ireland
DC Changeover System with Battery Protection Unit - Emergency lights commonly available in the market come with battery over-charging protection but no discharging protection. Here is a circuit that protects the battery from over-charging as well as over-discharging.__ Electronics Projects for You
DC Fault Protection for Audio Amplifiers - Circuit ideas how to replace traditional CD protection relays with MOSFETs __ Designed by R.G. Keen
Deep Discharge Protection for 12 V Batteries - NOTE: Must register on this site __ Designed by Published in Elecktor July/Aug, 2010
Design Notes 503: Dual DC/DC Controller for DDR Power with Differential VDDQ Sensing & ±50mA VTT Reference - 11/01/13 EDN-Design Notes Solid-state circuit breaker for microcontrollers. The LTC3876 is a complete DDR power solution, compatible with DDR1, DDR2, DDR3, and DDR4 lower voltage standards. The IC includes VDDQ and VTT DC/ DC controllers and a precision linear VTT reference. A differential output sense amplifier and precision internal reference combine to offer an accurate VDDQ supply. The VTT controller tracks the precision VTTR linear reference with less than 20mV total error. The precision VTTR reference maintains 1.2% regulation accuracy, tracking one-half VDDQ over temperature for a ±50mA reference load. Design by Ding Li
Detect & Disconnect Overvoltage - 04/25/96 EDN Design Ideas: The circuit in Fig.1 protects circuits and systems with power supplies that may exceed safe limits. One example is small consumer products that use external ac adapters; it's easy to mistakenly plug in the wrong adapter. Another example is a portable system that uses a rechargeable battery pack. if the battery pack is absent or fails to open during recharging, a high-compliance charger can deliver excessive voltages to the system Design by Kerry Lacanette, National Semiconductor Corp, Santa Clara, CA
Detects Low Voltage 120VAC Power Line - This hobby circuit will turn on a beeper when the line voltage drops below 100 volt AC . . . Hobby Circuit designed by David Johnson P.E.-July, 2006
Double the protection of a laser driver using a 1V power supply - 04/09/13 EDN Design Ideas: Drive a laser pointer with a single cell discharged to as low as 1V, and improve safety reliability with redundant current control transistors. Design by liao taishan
Dual Comparator Thermally Protects Lithium-Ion Battery - 18-Sep-03 EDN Design Ideas: Most manufacturers recommend that you don't change lithium-ion batteries at temperatures lower than 0°C or higher than 50°C. You can monitor both thresholds by adding a thermistor and dual (window] comparator to a lithium-ion battery charger (Figure 1). Set the low-temperature trip point at 2 Design by Mike Hess, Maxim Integrated Products, Sunnyvale, CA
Dual DC/DC Controller for DDR Power with Differential VDDQ Sensing & ±50mA VTT Reference - 11/01/13 EDN-Design Notes Solid-state circuit breaker for microcontrollers. The LTC3876 is a complete DDR power solution, compatible with DDR1, DDR2, DDR3, and DDR4 lower voltage standards. The IC includes VDDQ and VTT DC/ DC controllers and a precision linear VTT reference. A differential output sense amplifier and precision internal reference combine to offer an accurate VDDQ supply. The VTT controller tracks the precision VTTR linear reference with less than 20mV total error. The precision VTTR reference maintains 1.2% regulation accuracy, tracking one-half VDDQ over temperature for a ±50mA reference load. Design by Ding Li
Electronic Breaker - This circuit uses the on-resistance of the MOSFET as the current sensor. Reset it by removing the input power or the load. The circuit draws no current unless tripped. __ Designed by Andrew R. Morris
Electronic fuse emulates fast- or slow-blow fuses - 11/09/00 EDN Design Ideas: The electronic-fuse circuit in Figure 1 combines the properties of a current transducer and a solid-state relay to disconnect low power at preset levels. Using this circuit lets. PDF contains multiple circuits, scroll to find the one of interest Design by John A Hasse, Colorado State University, Fort Collins, CO
Emergency Light with Charger - 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
Emergency Stop - NOTE: Must register on this site __ Designed by Published in Elecktor July/Aug, 2010
Enhanced Security Bike LED Light - Adds movement detection and visual effects to enhance visibility to motorists.3 LEDs flash simultanuously in normal mode. Various light effects when a small movement or direction change is detected. All 3 LEDs light up for 1, 5 sec when braking occurs. __ Designed by Michel Bavin
Ensure Safety In Power-On Operation - 04/24/03 EDN Design Ideas: Buck converter handles battery-backup system - Computers find universal use in industrial-control systems. During power- and start-up sequences (booting], the outputs of such control systems may yield uncontrolled pulses before the Design by Jean-Bernard Guiot, DCS AG, Allschwil, Switzerland
Equip switchers with overcurrent protection - 06/24/99 EDN Design Ideas: Overcurrent protection is usually a necessary design feature of a switch-mode power supply to safeguard both the switcher and the load. Most PWM control ICs have internal overcurrent-protection circuits, and you can typically add auxiliary circuits around the IC to enhance this protection. For example, simple circuits enhance the operation of the common family of UC3842/3/4/5 (Unitrode Corp, www.unitrode.com) PWM-control ICs (Figure 1). Design by Robert N Buono, Buono Consulting, Ringwood, NJ
External components provide true shutdown for boost converter - 16-Mar-06 EDN Design Ideas: An additional MOSFET and resistor solves the problem by opening the unwanted current path during shutdown Design by Navid Mostafavi, Maxim Integrated Products Inc, Sunnyvale, CA
Failed Power Light - This back-up lamp stays off as long as light falls on the CdS photocell from either the NE-2 or from room ambient light. So, if the power fails at night, the lamp will light. The 6 volt lamp should be directed away from the photocell __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Fast Electronic Fuse - A fast electronic fuse designed to operate on 230V AC with an adjustable trip current. __ Designed by Miroslav Adzic-Serbia Montenegro
Fault-latch protects switchers - 02/19/04 EDN Design Ideas: Many power-supply designers like to have a regulator latch off in the event of an overcurrent situation or other fault condition. Yet, many PWM controllers do not internally support this latch-off function. Most do, however, have a Design by Craig Varga, National Semiconductor, Phoenix, AZ
Folds back current during fault conditions - 11/28/02 EDN Design Ideas: You can use monolithic linear regulators at currents lower than 5A for most applications. Most manufacturers of these devices integrate current-limiting and thermal shutdown to prevent damage during fault conditions. For currents greater than 5A, most linear supplies use controllers that allow the user to select the pass element to handle different current requirements Design by Martin Galinski
For want of protection Devices - 02/03/97 EDN-Design Feature A variety of devices protects sensitive circuits against overvoltage or overcurrent conditions, thereby preventing overheating, avalanche breakdown, and device burnouts. Design by Design Feature by Bill Travis, Senior Technical Editor
Fuse Monitor/Alarm - a simple way to see if a fuse has blown without removing it from its holder __ Designed by Andy Collison
Ground Fault Indicator - Check out your AC Outlets for Possible Hazzards. __ Designed by G.L. Chemelec
Guard Against Battery Reversal - 07/06/95 EDN Design Ideas: The circuit in Fig 1 protects a battery-operated system in two ways Q1 prevents damage from the flow of reverse current that could occur if you install the battery backward, and Q3 prevents the excessive current flow that could occur with a sudden load increase or a short circuit. A properly installed battery fully enhances Q1 by pulling i Design by Dana Davis, Maxim Integrated Products, Sunnyvale, CA
Guard Amplifier outputs against overvoltage - 07/05/07 EDN Design Ideas: An automotive-protection circuit withstands repeated insults of direct short circuits to the full battery voltage Design by John Guy, Maxim Integrated Products, Sunnyvale, CA |
