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Current Sources Page

Current sources

Many applications require current sources rather than voltage sources. Current source provides a constant current to the output. This currentdoes not depend on the output voltage. An idea current source is a high output impedance device: it willsupply current, but does not show in other ways on the load circuit.When you need a low-current source, using a linear regulator isa typical approach. When you need a high-current source, using a linear regulator is inadvisable, because of the high power dissipation in the series resistor. To solve the wasted-power problem, you can use a switch-mode regulator. In some applications current signal sources are needed for measurement purposes. One very easy trick is to insert a large value resistor (compared to the impedance of the circuit measured) in series with the generator. This willessentially convert your constant voltage generator to a constantcurrent source. This is not completely ideal current source, butgood enough approximation for most applications, where the load resistance is much smaller than the current limiting resistor resistance.

• 40V current source operates from -40 to +85๏ฟฝC - wide-output-current range sources that accommodate a wide supply and temperature range, based on LM317    Rate this link
• Circuit forms novel floating current source - This novel floating current source represents an improved way to bias ISFET sensors.    Rate this link
• Current source has high output impedance - composite 10-mA current-source configuration that has a compliance voltage of 5 to 42V, a set-current error of less than 1% and an output impedance of greater than 100 megaohms    Rate this link
• Digital current source is nonvolatile - Digitally programmable current sources that feature automatic trimming and retain the setting despite power-down cycles are useful in applications such as RF- and laser-communications drivers. This circuit is particularly suited for setting the drive current for the optical pump in widely tunable VCSELs (vertical-cavity surface-emitting lasers).    Rate this link
• High-speed regulator makes great current source - bandwidth of this circuit measures more than 1 MHz, only the selected MOSFET and the ratings of the input supply's bypass capacitors limit the voltage compliance    Rate this link
• L200 Regulator Circuit - easy to build a power supply with one single L200 IC, offers a variable current limit of up to 2 A, as well as voltage regulation    Rate this link
• Precision current sink costs less than $20 - simple active load circuit for current from 1 mA to 1A and voltage from 3 to 40V    Rate this link
• Programmable current source powers charger - digitally programmable current source capable of sourcing currents as high as 2.55A    Rate this link
• Simple scheme keeps current drain constant - It is sometimes advantageous to keep the overall current consumption of an electronic device constant. This circuit outptu variable current to 5V load and maintains a constant current of approximately 102 mA in the power supply input.    Rate this link
• Switching regulator forms constant-current source - When you need a high-current source, using a linear regulator is inadvisable, because of the high power dissipation in the series resistor. To solve the wasted-power problem, you can use a switch-mode regulator. This circuit uses an LM2576 adjustable regulator. It needs only a few external elements and has an adjustable sensing input, which you use for controlling the output current.    Rate this link
• Variable 3 - 24 Volt / 3 Amp Power Supply - regulated power supply can be adjusted from 3 to 25 volts and is current limited    Rate this link
• Variable Power Supply - based on versatile L200 voltage regulator, independent voltage (3-15V) and current (10mA-2A) limits    Rate this link
• Voltage-to-current converter makes a flexible current reference - This voltage-to-current converter design can both source and sink current. The circuit is more flexible than some traditional current references that require different topologies for current sourcing and sinking. Also, you can easily adjust the value of the current reference by simply adjusting the circuit's input voltage.    Rate this link

• Linear Power Supply Page

   

   

  General information on low voltage linear power supplies

  Linear power supplies use dissipative regulator componentsto achieve regulation. This dissipative regulation meansconversion of excessive power to heat. When using a linearregulator you have usually an unregulated power supply which givessomewhat higher voltage than your electronics needs. You put adissipative regulator between the power source and your electronicscircuit. This regulator keeps the voltage on the output stable(as long as the input voltage is high enough). The regulator itselfconverts the the power determined by voltage difference (unregulated voltage - output voltage) times output current to need.Linear power supplies are generally easy to construct (there are very easy to use ICs for this or they can bebuilt quite easily using discrete components) and can easily givegood quality output voltage (stable output voltage andlow noise). The disadvantage of them is loweffiencely (lots of heat dissipated in power supply).The linear regulator used in regulated linear power supplies, utilises simple techniques of controlled energy dissipation to achieve a regulated output voltage independent of line and load variation. It is, therefore, inherently inefficient, especially when a wide input voltage range has to be catered for.When building a linear regualated power supply which takesmains voltage and outputs low voltage, the following parts are needed;a buly low frequency mains transformer, large heat-sinking is required to dissipate the heat generated by the regulating element and very large filter capacitors are required to store enough energy at the voltage to maintain the output for a reasonable length of time when the mains source is removed (during mains AC voltage zero crossing). Note that linear power supplies can be a non-linear load to the mains power. The reason for this is how the rectifier circuit and the filtering capacitors work together with the transformer AC output. The rectifier connected to the transformer secondary starts to conduct when the output voltage from the transformer secondary is higher than the voltage in the filtering capacitor. This usuallyhappens at 30-75 degrees from mains zero crossing depending on the circuit load and filtering capacitor size. Usually the rectifier stops to conduct quite quicly after the highest secondary voltage is reached (at 90 degress from zero crossing). This means that the current goes to the rectifier capacitor only for somepart of the mains voltage (high current then) and most of thetime no current goes to the filtering capacitor. This is clearlya non-linear load.

  Theory

   

  • A Designer's Guide to the L200 Voltage Regulator -    Rate this link
  • Change improves regulators reliability - standard circuit for adjustable, 3-terminal regulators (LM317, LM350, etc) suffers from a designed-in fault: If the potentiometer R2s wiper loses contact, the regulators output goes high    Rate this link
  • DMOS delivers dramatic performance gains to LDO regulators - LDO regulators with pnp pass elements nearly obsoleted the early npn linear regulators    Rate this link
  • Emitter-Follower Boosts Linear Regulator's Output Current - an external emitter-follower increases the output current while maintaining the low quiescent current of this LDO regulator    Rate this link
  • Extend the input range of a low-dropout regulator - Because of process limitations, all ICs have an input-voltage limitation. This limitation can be cumbersome when you try to step down a high supply voltage to a lower, regulated voltage using a dc/dc converter, such as a linear regulator. Adding a FET to the input of a linear regulator creates a dc/dc converter with a wider input-voltage range than the range of the regulator alone. The excess voltage and, therefore, power occurs in the FET.    Rate this link
  • Full Wave Rectification - This article describes how full wave rectification using four diodes works.    Rate this link
  • Full-wave DC power supply - This is a simulation of a simple DC power supply based on a full-wave rectifier. This power supply uses center-tapped transformer and two diodes. This type of circuit is also known as a biphase rectifier.    Rate this link
  • Increasing Regulator Current - Although the 78xx series of voltage regulators are available with different current outputs, you can boost the available current output with this circuit. A power transistor is used to supply extra current to the load the regulator, maintaining a constant voltage.    Rate this link
  • Inside a Power-Cube Transformer - How those little things convert mains AC to safe low voltage DC    Rate this link
  • Increasing Regulator Current - you can boost the available current output of 78xx series of voltage regulators with this circuit    Rate this link
  • Keep linear regulators in their safe zone - thermal characteristics of regulators depend on their operating conditions and the system's load    Rate this link
  • Method of Determining Secondary Current Ratings in D.C. Circuits - This document gives you the equations for Half Wave Rectifier (HWR), Full Wave Center Tap (FWCT), Full Wave Bridge (FWB) and Dual Complementary Rectifies (DCR). Also example circuits are given. This document gives also information how to add a regulator to the power supply output.    Rate this link
  • Power supplies - theory    Rate this link
  • Rectifier Applications Handbook    Rate this link
  • Transformer Facts Technical Bulletin No.1: Application Notes on Rectifier Transformers    Rate this link
  • Understanding linear regulators - Linear regulators convert unregulated dc voltage to regulated dc voltage. are good vehicles to use to begin a voltage-regulator study.    Rate this link
  • Unregulated Power Supply - sample circuits and some information which describes it's operation and calculation of component values    Rate this link
  • Unregulated power supply design    Rate this link
  • Voltage regulators (stabilizers) 78xx a 79xx by ST - warning about some possible problem if the regulator load is too low    Rate this link
  • Zener Voltage Regulator CALCULATOR    Rate this link

  Fixed voltage regulated

  Very many devices need well regulated power.The most typival approach used electronics devices is to to use a transformers thatwork directly from the domestic electricity supply at 60 Hz (in the U.S.A, 50 Hz in some other countries)and this is followed by rectifier + regulator circuitry that uses linear regulation. In this type of regulator a transistor, or a special IC, is used as a series resistor whose value of resistance is controlled so as to maintain the output voltage constant despite variations in load.This work well, is quite simple to make, but is quite inefficient as a lot of power is wasted as heat (wasted heat is define by formula: drop voltage over regulator (volts) * current taken (in amperes) = power loss (in watts)).Linear regulation works wery well in low power applications where some lost heat is no problem (in higher power applications switched more power supplies are nowadays preferred because of lesswasted power).

  • 12 Volt 30 Amp Power Supply - This circuit uses a single 7812 IC voltage regulator and multiple outboard pass transistors (TIP2955). This power supply can deliver output load currents of up to 30 amps.    Rate this link
  • 12V RMS to 10V Voltage Regulator - will take a 12V RMS sinusoidal input from a transformer and provide a 10V DC output at 100 mA with very good regulation    Rate this link
  • 12 Volt to 9 Volt DC Converter    Rate this link
  • 13.8V 20A power supply - Regulated DC power supply, short circuit safe, and with current limiter. This PSU has been especially designed for current-hungry ham radio transceivers. It delivers safely around 20Amps at 13.8V. For lower currents, a separate current limiting output, capable of 15ma up to a total of 20A has been added. The base of this design is a simple 12V regulator (7812) and power transistors.    Rate this link
  • 48 Volt Phantom Power Supply - This is a simple 48 V regulated linear power supply design that will provide up to 60 mA of current. This circuit is based on the Texas Instruments TL783C high voltage adjustable linear regulator IC. This circuit is short circuit protected.    Rate this link
  • 78xx regulator board - circuit board and ccircuit for making voltage regulators based on 78xx ICs, in pdf format, text in Finnish    Rate this link
  • A constant 5 volts DC power supply - This is an example of a power supply to power anything requiring 5 volts DC. This circuit takes low voltage AC in (9-16V AC).    Rate this link
  • Active preloading provides sinking capability - a simple add-on circuit enables a unipolar power supply, usually a current-sourcing circuit only, to sink current from a load    Rate this link
  • Circuit reduces VCC ripple in audio band - regulator circuit which reduces noise and ripple by at least 35 dB over the audio range of 100 Hz to 20 kHz and provides a clean source of 5V power for driving audio circuits in portable applications such as cellular phones and multimedia notebook computers    Rate this link
  • DC power supply - simple circuit based on 78xx fixed voltage regulator IC, those ICs are available for some fixed voltages between 5 and 24V    Rate this link
  • Discrete LDO Regulator - The discrete LDO design presented here came about because of the need for an LDO (low drop-out regulator) for 5V designs. There are better performing LDO parts, but they tend to be either single sourced or expensive. This one can be made from common components. The performance parameters are very crude : 5V nominal at up to 10mA from 6-16V.    Rate this link
  • Explanamtion and experiment about regulated DC power supply - many power supply designs for different voltages, built from discrete components    Rate this link
  • Increasing Regulator Current - you can boost 78xx regulator output with one power transistor    Rate this link
  • Linear supply uses switch-mode regulation - You can use simple circuits to implement small, regulated plug-in power supplies. This basic and versatile 5V supply uses a zener diode and an emitter-follower transistor.    Rate this link
  • Logic PSU with Over Voltage Protection - 5 volt regulated power supply for TTL and 74LS series integrated circuits, includes output overvoltage fault protection    Rate this link
  • Low-drop regulator - outputs 5V at 1A, constructed from discrete components, in postscript file format    Rate this link
  • MOSFET circuit ups regulator's output current - use a current mirror and a power MOSFET to increase the output-current capability of an IC-voltage regulator    Rate this link
  • Power Supply for Preamplifiers - gives +/-15V outputs and takes power from external AC power supply    Rate this link
  • Regulated 12 Supply - provides a regulated 12 volts at 0.5 amp to a load, built from discrete components    Rate this link
  • Regulated 12 Volts DC Power Supply for Vacuum Tube Heaters - this 7812 based circuit circuit can be used with low-hum audio applications such as microphone preamps and for other applications that require well regulated 12 volts    Rate this link
  • Regulator excels in noise and line rejection - certain electronic circuits require extremely low-noise power supplies and this circuit provides very good quality power output    Rate this link
  • Regulator generates sub-bandgap voltages - 100-mA regulator that uses a dual linear-regulator IC to produce output voltages below 1.25V from 2.9 to 5.5V input-voltage range    Rate this link
  • Sam's Schematic Collection of various circuits - includes many regulated power supply circuits    Rate this link
  • Simple 5V power supply for digital circuits    Rate this link
  • The Spyder - an Eight-Output Pedalboard Power Supply - outputs regulated 9V DC    Rate this link
  • Universal DC-DC Convertor - This circuit will generate a smaller DC output voltage from a larger DC input voltage.It is quick and simple to make and by changing the value of the zener diode, the circuit can be universally adapted to provide other output voltages. The circuit and all diagrams represent a DC convertor with 12V battery input and 9Volt DC output.    Rate this link
  • Voltage Regulator - simple regulated 12V power supply using one transistor regulator circuit    Rate this link
  • Zener Diode Calculator - This calculator is designed to give the wattage and resistance of the circuit power resistor, the voltage and wattage rating of the Zener diode and general design schematic for the circuit. Enter the maximum and minimum voltage inputs; enter the voltage output and the anticipated current rating. Click on Calculate and the results will be displayed.    Rate this link

   

  Adjustable regulated power supplies

   

  • 0-30 VDC Stabilized Power Supply With Current Control 0.002-3A - This is a high quality power supply with a continuously variable stabilised output adjustable at any value between 0 and 30VDC. The circuit also incorporates an electronic output current limiter that effectively controls the output current from a few milliamperes (2 mA) to the maximum output of three amperes that the circuit can deliver. This feature makes this power supply indispensable in the experimenters laboratory as it is possible to limit the current to the typical maximum that a circuit under test may require, and power it up then, without any fear that it may be damaged if something goes wrong. There is also a visual indication that the current limiter is in operation so that you can see at a glance that your circuit is exceeding or not its preset limits.    Rate this link
  • 0-30 Volt Laboratory Power Supply - This circuit provides 0-30 volts, at 1 amp, maximum, using a discrete transistor regulator with op-amp feedback to control the output voltage. This power supply has constant current mode suitable for charging batteries.    Rate this link
  • 0 - 300V Adjustable Power suppy - This is a simple circuit which can provide an adjustable voltage source of 0 to 330 Volt. The supply is short-ciruit proof: the current is limited to about 100mA.    Rate this link
  • 10 amp Power Supply - This is a simple regulated power supply that can give adjustable voltage from 3 volts to 18 volts. The current capacity is 10 amperes. This circuit is overcurrent protected. This circuit can be modified for higher current ratings if needed.    Rate this link
  • 1.2-25VDC at 4A power supply schematic - built using discrete transistors and 741 opamp, read    Rate this link
  • 1A Variabe Power Supply - This circuit takes in 240V AC and outputs a regulated DC at voltage sange of 2-15V DC up to 1.5A.    Rate this link
  • Adjustable power supply using LM317 - voltage regulator for 1.2V to 35V output voltages and up to 1A load    Rate this link
  • Build a Variable Voltage Supply for Cheap - This is a variable voltage 1.5A supply that can be built cheaply and used for bench experimeting. With a 24VDC wall wart, this board can produce anywhere from 23V to 1.2V    Rate this link
  • High Current Regulated Supply - uses pair of 3N3055 transistors to give out currents up to 15A    Rate this link
  • L200 Regulator Circuit - easy to build a power supply with one single L200 IC, offers a variable current limit of up to 2 A, as well as voltage regulation    Rate this link
  • Variable 3 - 24 Volt / 3 Amp Power Supply - regulated power supply can be adjusted from 3 to 25 volts and is current limited    Rate this link
  • S๏ฟฝ๏ฟฝdett๏ฟฝv๏ฟฝ j๏ฟฝnnitel๏ฟฝhde 0-24V 4A - 0-24V 4A adjustable power supply, text in Finnish    Rate this link
  • Variable Power Supply - based on versatile L200 voltage regulator, independent voltage (3-15V) and current (10mA-2A) limits    Rate this link
  • Variable Regulated Power Supply - This is a simple, but low-ripple powersupply, and an excellent project if you're starting out in electronics. It will suit your needs for most of your bench testing and prototype applications. The output is adjustable from 1.2 volts to about 30 volts. Maximum current is about 1.5 amp.    Rate this link

  Switched Mode Power Supply Page

  Step-up converters

   

  • 2 Watt Switching Power Supply - from 6V to 14V    Rate this link
  • +30V power supply with +5V - This is a power supply which makes about +30V with +5V power supply. The high DC voltage (up to +50V) is made with the alternating voltage using the voltage amplification rectification circuit.    Rate this link
  • Battery booster delivers 75W - uses isolated DC/DC converter in a nonisolated configuration to boost a 48V battery voltage to 60V    Rate this link
  • Boost 3.3V to 5V with tiny audio amplifier - This charge-pump circuit quietly converts a 3.3V source to 5V at 500 mA. National's (www.national.com) LM4871LD power amplifier makes this design idea both possible and practical.    Rate this link
  • Boost converter controls 12V fan from 5V supply - temperature-controlled PWM boost converter allows operation of a 12V brushless dc fan from a 5V supply    Rate this link
  • Boost converter generates three analog rails    Rate this link
  • Coilless step-up converter yields dual outputs - provides regulated 5 and 3V supplies from a wide input range without the need for inductors    Rate this link
  • Converter has high efficiency at low loads - micropower components and circuit design of this converter enable it to maintain 90% efficiency for load currents below 8 mA, circuit outputs 5V DC    Rate this link
  • DC to DC Converter - will produce a 85V voltage from +3V, usable for low power applications    Rate this link
  • DC to DC Converter - low power converter which converts 3V to 85V, uses standard 12 VAC center tapped power transformer and single bi-polar NPN transistor    Rate this link
  • Hex inverter makes low-cost switching regulator - simple and low-cost circuit converts 5V to 12V    Rate this link
  • High power 12 V to 300 V invertor for high repeat rate medium power strobes    Rate this link
  • High-voltage circuits for electrostatic microphones - circuits that can generate the required high-voltage for electrostatic microphones used in bat detectors, circuit can be used to generate a voltage of about 70V using a current of about 4 mA at 6V input voltage    Rate this link
  • Li-ion boost circuit uses no inductors - circuit to mainstain regulated 3.3V supply for portable applications    Rate this link
  • Low-cost switcher converts 5 to 24V - low-cost, three-transistor low power boost switching regulator    Rate this link
  • One 9V battery gives +18, +25, +33V - how to make voltage booster using MAX1044 charge pump converter IC    Rate this link
  • Panel meter power supply - isolated 9.1V 2-5 mA output from 8-30V input, in pdf format, text in Finnish    Rate this link
  • Single cell lights any LED - This circuit allows you to light any type of LED from a single cell whose voltage ranges from 1 to 1.5V. This range accommodates alkaline, carbon-zinc, NiCd, or NiMH single cells. The circuit's principal application is in LED-based flashlights, such as a red LED in an astronomer's flashlight, which doesn't interfere with night vision. White LEDs make handy general-purpose flashlights. You can use the circuit in Figure 1 with LEDs ranging from infrared (1.2V) to blue or white (3.5V).    Rate this link
  • Step-up/step-down converter takes 2 to 16V inputs - switcher where input can range above and below the regulated voltage, circuit accommodates a wide range of input and output voltages and supplies output currents as high as 500 mA    Rate this link
  • Get just enough boost voltage - Adding a current-mirror circuit to a typical boost circuit allows you to select the amount of boost voltage and to ensure a constant difference between the input and the output voltages. This circuit is useful for high-side-drive applications, in which a simple voltage doubler is unacceptable because of the voltage range of the components involved or where the input voltage can vary widely. You can also use the circuit at the front end of a power supply to ensure that the PWM controller has enough voltage to start correctly in low-input-voltage conditions. The circuit maintains a 10V difference between VIN and VOUT, but you can easily change it to provide other voltages.    Rate this link

   

  Step-down converters

   

  • 3.3-V Supply Taps Power From The 12 V PCI Bus    Rate this link
  • 5-to-1.8V Converter Works Without Magnetics    Rate this link
  • Add trimmable current limit to dc/dc supply - you can add a simple, two-transistor circuit to a standard, step-down dc/dc converter to provide an adjustable limit for the output current    Rate this link
  • Bipolar transistor boosts switcher's current by 12 times - This circuit uses a minimal number of external parts to raise the maximum output current of a 0.5A buck switching-regulator IC to more than 6A.    Rate this link
  • Boost controller drives buck converter - by adding an external switching transistor, you can use a step-up dc/dc converter to step down voltages to produce an efficient battery-powered power supply, this example circuit can step down inputs as low as 2V to outputs as low as 1.25V, with efficiency as high as 80%    Rate this link
  • Buck converter works efficiently from phone line - A switching converter provides an inexpensive way to generate 5V, 18 mA (48V, 5 mA maximum) directly from a standard phone line.    Rate this link
  • Buck regulator generates flexible VTT for PECL - circuit to generate output which can both source and sink current    Rate this link
  • Circuit provides 1.5V, 7A bus termination    Rate this link
  • Gate-drive method extends supply's input range - Industrial and telecom applications often require a nonisolated, low-voltage supply from a high-voltage input. IC manufacturers have responded to that need with the application of high-voltage processes and offer control ICs that work to 50V and higher. That voltage is sometimes insufficient, and you need further design techniques to extend the input voltage. This buck converter represents one such technique. This example circuit generates regulated 12V 0.2A output from 20-110V DC input voltage.    Rate this link
  • Inductorless converter provides high efficiency - produces a regulated 2V output with as much as 100 mA of load-current capability from 2.4 to 6V input voltage    Rate this link
  • SEPIC generates 5V at 100 mA - Some applications require an input voltage higher than the breakdown voltage of the IC supply pin. In boost converters and SEPICs (single-ended primary-inductance converters), you can separate the VIN pin of the IC from the input inductor and use a simple zener regulator to generate the supply voltage for the IC. This design shows a SEPIC that takes a 4 to 28V input and generates 5V at 100 mA.    Rate this link
  • Single resistor improves V2 converter - V2 control offers a significant improvement in transient response by using two voltage feedbacs, example circuit is for generatign voltages in 1.8-3.3V range    Rate this link
  • Step-up/step-down converter takes 2 to 16V inputs - switcher where input can range above and below the regulated voltage, circuit accommodates a wide range of input and output voltages and supplies output currents as high as 500 mA    Rate this link
  • Supply derives 5 and 3.3V from USB port - This circuit derives its power from a USB port and produces 5 and 3.3V supply rails for portable devices, such as digital cameras, MP3 players, and PDAs. The circuit allows the port to maintain communications while, for example, charging a lithium-ion battery. IC2 boosts the battery voltage, VBATT, to 5V, and IC3 buck-regulates that 5V output down to 3.3V.    Rate this link
  • Switched-capacitor regulator provides gain - switched capacitor idea to convers 12V to 3.3V or 5V    Rate this link
  • The MIC4680 Switching Regulator - simple circuit which outputs +5V    Rate this link
  • Three-input supply powers 3.3V portables - single-ended primary-inductance converter accepts input voltages ranging from 3 to more than 6V and produces a regulated 3.3V, 200-mA output    Rate this link
  • Three parts provide tenfold increase in switcher current - Industrial-control circuits often derive their power from widely varying sources that can exceed the 40V maximum rating of popular switching ICs. This Design Idea presents a simple, flexible, and inexpensive buck switcher that converts an input voltage as high as 60V to 5V at several amps. The circuit is unique in that it boosts current with almost no compromise in performance, size, or cost. This circuit uses LM2597HV switcher IC.    Rate this link
  • Use a 555 timer as a switch-mode power supply - This article shows how to turn a 555 PWM circuit into an switch-mode power supply with only one simple equation. The example circuit is set to oscillate at approximately 60 kHz at a high duty cycle. You can supply 5V at 1.5A with an input of 9 to 40V. With 12V input, 5V, 1.5A output efficiency is approximately 70%, and it drops to 65% with a 40V input.    Rate this link
  • Wall-cube dc/dc converter is 85% efficient - ubiquitous 12V wall cube generates an unregulated dc voltage of 8 to 18V, depending on line voltage and load, this circuit generates a regulated 5V 400 mA from it very efficiently    Rate this link

   

  Dual polarity output power supplies

   

  • ๏ฟฝ12V supply accepts 9 to 30V inputs - delivers more than 3.6W at ๏ฟฝ12V and operates from inputs of 9 to 30V    Rate this link
  • Current source forms unusually simple regulator - simple regulator uses a switching current source to drive a pair of shunt zener regulators, circuit produces ๏ฟฝ15V dual outputs, for total output power of approximately 400 mW form 100-400V DC source    Rate this link
  • Inverter forms high-efficiency rail-splitter - switched-capacitor voltage inverter can be used as "rail splitter" to provide bipolar, dual-rail power supply    Rate this link
  • Simple DC-DC Converter Allows Use of Single Battery - Have you ever wanted to build a circuit to run off a single 9 Volt battery only to find you needed levels like +12 and -12 Volts? The thought of multiple batteries might have put you off. Why not use a simple DC to DC converter?    Rate this link
  • Simple regulator provides ๏ฟฝ12V - simple circuit can provide ๏ฟฝ12V from a 5V input using only one switching-regulator IC and a few off-the-shelf components    Rate this link