Safe Hot Swapping using the LTC1421 - DN139 Design Notes __ Linear Technology/Analog Devices
Simple Circuit 3.3 volt power supply - Among the power supplies presented here, this is a well regulated type that can deliver up to 1.5A current from a wide range of input voltage of 5V to 25V dc. See LM317 calculator if you want to know how to get the 3.3 V output. __ Designed by KB Kaminski
Simple Circuit regulated power supply with overcurrent trip - Here's a circuit for a relatively simple regulated power supply which has well controlled characteristics, including a clever over-current trip. __ Designed by Richard Torrens
Simple Circuit Switching Regulator - NOTE: Scroll down - When batteries are used to power lower voltage circuits, a switching regulator is desirable to conserve battery life. There are excellent ICs that can do the job with great efficiency and small size. An example is the Maxim (www.maximic.com) MAX639 which converts inputs from 5.5 to 11.5 volts to 5 volts at up to 225mA. The only additional parts are an inductor, schottky rectifier and a couple of capacitors. The following circuit is a discrete switcher similar in power handling capability to the MAX639. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Simple Circuit VCOM adjustment uses any logic-supply voltage - 09/30/04 EDN Design Ideas: All TFT [thin-film-transistor] LCD panels require at least one appropriately tuned VCOM signal to provide a reference point for the panelís backplane. The exact value of VCOM varies Page includes several designs. Scroll to find this one __ Circuit Design by Peter Khairolomour and Alan Li, Analog Devices, San Jose, CA
Soft Start power Supply - Two soft start power supplies. The output voltage slowly increases to the desired output. __ Designed by Miroslav Adzic
Solar Cell Phone Charger - This little gadget uses a small 3 volt solar cell to charge a 6 volt NIC ad battery pack which, in turn, may be used to charge many models of cell phones and other portable devices with the addition of a suitable low-dropout voltage regulator. The circuit "scavenges" energy from the solar cell by keeping it loaded near 1.5 volts (maximum energy transfer value) and trickle charges the internal battery pack with current pulses. The simple circuit isn't the most efficient possible but it manages a respectable 70% at 100 mA from the cell and 30% when the cell is providing only 25 mA which is actually pretty good without going to a lot more trouble or using more exotic components. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Split Supply Generator - Occasionally a designer needs a dual power supply to power a circuit that is operating with signals near or at ground but the only available supply is a single polarity, usually positive. Many excellent IC solutions are available but a suitable solution for many projects may be constructed from "junk box" parts. The simple circuit below will generate about 9 volts and -4 volts from a single 5 volt supply with sufficient current to power a simple op-amp circuit. The positive voltage drops to about 7 volts when supplying 7 mA and the negative voltage drops to about 3.5 volts when supplying 3.5 mA (1k loads). Although this isn't exactly a +- 15 volt supply, this is plenty of voltage and current for many op-amp circuits and will allow the output of most op-amps to swing below zero volts and will allow most op-amp inputs to measure voltages below zero volts. This circuit uses the CD4049 which is a high current version of the CD4069 which will also work with somewhat lower current capability. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Stabilised power unit - i made the stabilised power unit which used the switching regulator. AC100 V is used for the input of the power unit. The output voltage can be changed from 5 V to 30 V. The output current can pour a maximum of 4 A. I made this power unit as the power unit of the electronic circuits making for the experiment __ Designed by Seiichi Inoue
Three-Terminal Adjustable Regulators - NOTE: Scroll down - The unregulated DC supply is a very common type and the simple regulator shown in fig.1 may be added for projects that require a stable voltage. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Two AA cells power step-down regulator - 01/07/99 EDN Design Ideas: (Scroll to find this one) DC/DC conversion is particularly challenging when both the input and output voltages are low. Step-up ICs that operate with inputs lower than 1V are available, but step-down ICs that accept input voltages Page includes several designs. __ Circuit Design by Len Sherman, Maxim Integrated Products, Sunnyvale, CA
UltraLow Noise Switching Power Supplies Simplify EMI Compliance - DN316 Design Notes__ Linear Technology/Analog Devices
Universal PSU - A Universal Power supply based on the L200 regulator, which includes an outboard pass transistor to boost output currents up to 4 amps. __ Designed by Volker Jeschkeit
VCOM adjustment uses any logic-supply voltage - 09/30/04 EDN Design Ideas: All TFT [thin-film-transistor] LCD panels require at least one appropriately tuned VCOM signal to provide a reference point for the panelís backplane. The exact value of VCOM varies Page includes several designs. Scroll to find this one __ Circuit Design by Peter Khairolomour and Alan Li, Analog Devices, San Jose, CA
Voltage Regulator - This circuit above uses a 13 volt zener diode, D2 which provides the voltage regulation. Aprroximately 0.7 Volts are dropped across the transistors b-e junction, leaving a higher current 12.3 Volt output supply. This circuit can supply loads of up to 500 mA. This circuit is also known as an amplified zener circuit __ Designed by Andy Collison
Wide-range regulator Delivers 12V, 3A output from 16 to 100V source - 06/23/05 EDN Design Ideas: Buck regulator tackles high input voltages __ Circuit Design by Wayne Rewinkel, National Semiconductor, Schaumburg, IL