General
- Glossary of Power Conversion Terminology
- Inside a Power-Cube Transformer - what's inside those small transformers you have all around in your house plugged to the power outlets and powering small electronic equipments with low voltage
- Power Supply Failures - power supply failures can be frustrating, expensive, and time-consuming events because many power supplies are highly complex circuits, with many components operating near the edge of their envelope, and when they fail, they tend to destroy most of the failure evidence with them
General power supply design
- Avoiding the Seven Sins of Power Supply Design - power supply designers can commit seven specific sins that cost time and money
- Choosing a heat sink: some tips and recommendations
- Design guidelines help dc/dc converters work properly over long lines - some background and design tips help ensure optimum converter operation under various long line conditions
- Designing Power Supplies the Easy Way - Very High Voltage ICs, or VHVICs, make designing a power supply easy
- Fault Tolerant Power Supply System Uses the Droop Method of Current Sharing
- Feedback isolation augments power-supply safety and performance - properly designed isolated feedback is crucial to maintaining safety on many power supply designs
- Just-In-Time Power Supply Design - just-in-time power supply design is increasingly untenable because simple power supply is not so simple anymore
- Linear Supplies feel the (lack of) heat from switchers in low-wattage applications - ICs that implement advanced supply techniques are challenging linear supplies by lowering costs, cutting size, and increasing efficiency
- Linear Supplies feel the (lack of) heat from switchers in low-wattage applications - ICs that implement advanced supply techniques are challenging linear supplies by lowering costs, cutting size, and increasing efficiency.
- Linear vs Switching Supplies: Weighing All the Options - the choice between linear and switching board-level power supplies is sometimes clear-cut but can be sometimes hard to do
- Power Conversion in Line-Powered Equipment - application note in pdf format
- Power.national.com - collection of power supply design information from National Semiconductor
- Powering the big microprocessors - modern microprocessor power-supply design must furnish many amps at a tightly controlled voltage level and respond quickly to heavy load transients
- Power-supply reliability: a practical improvement guide - path to high reliability is a well-managed process that starts in the product's definition phase and continues long after the first shipment
- Proper layout and component selection control power-supply EMI - All power-supply components, including voltage regulators, inductors, and transformers, and their layout determine the amount of EMI a supply generates. An overview covers the mechanisms and physical principles governing the generation and propagation of power-supply electrical noise.
- Truth or Consequences of LDO Regulators - low-dropout regulator, better known as LDO, is a special type of regulator where the minimum required voltage between the input-output voltage (the dropout voltage) is significantly smaller than predecessor parts
Power distribution in circuit board
- DC-DC Converters Deliver Better Performance For Distributed Power - with their enhanced efficiency and features, modular components deliver high currents and low voltages, in small packages
- Decoupling capacitors: use them or fail
- Distributed power takes center stage - distributed power has become a strategic architecture for digital systems
- Generating 3.3V from 5V - low drop out regulators are the answer
- Good design enables hot insertion of power supplies - hot insertion of power supplies offers many advantages, but it can cause lots of problems unless you prepare for it in your design
- High-Density Power Components Add Flexibility To Distributed-Power Design - correct load partitioning, thermal management, and filtering help to achieve successful distributed-power solutions
- High-end digital systems give a thumbs down to rules of thumb - lower voltages, higher current transients, and higher clock rates render rules of thumb uselsss for designing power-distribution-system decoupling networks
- Hot-swap your way to high availability - follow live-insertion board-design guidelines to keep the sparks from flying
- Packaged DC-DC Converters Solve Distributed Power Dilemmas when used properly, off-the-shelf, isolated dc-dc converters save space, reduce component count, and simplify design
- Simple Techniques Minimize Cross-Coupling in Distributed Power Systems
- Use local bypass capacitors to meet rigorous high-speed-system demands - when conductors look like inductors and supply lines must absorb amps of fast-edge glitchiness, low-inductance, locally applied bypass capacitors come to the rescue
Mains power connection
Mains power filtering
Regulatory compliance
Component selection
Measuring power supplies
Wiring power supplies to load
Car power
Portable equipment power
NOTE: High voltage power supplies are very dangerous circuits which should only be built by persons who know exactly what they are doing and do it safely. High voltage power supply can easily kill you if you do mistakes with it.
Adjustable high voltage supplies
Low power
Safety notice: Even though very many low power high voltage circuit produce vely low currents which are not as such usually dangerous, they can still produce dangerous shocks.
High power
High voltage spark circuits
High voltage experimenting
Stun gun circuits
Special application power supplies
Theory
Unregulated power supplies
Fixed voltage regulated
- 12 Volt 30 Amp Power Supply - uses a single 7812 IC voltage regulator and multiple outboard pass transistors, this power supply can deliver output load currents of up to 30 amps
- 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
- 12 Volt to 9 Volt DC Converter
- 78xx regulator board - circuit board and ccircuit for making voltage regulators based on 78xx ICs, in pdf format, text in Finnish
- 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
- Car 12V converter - simple circuit to connect car 12V to 9V, 7.5V or 6V
- 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
- DC power supply - simple circuit based on 78xx fixed voltage regulator IC, those ICs are available for some fixed voltages between 5 and 24V
- Explanamtion and experiment about regulated DC power supply - many power supply designs for different voltages, built from discrete components
- High Current Power Supply - takes very few parts and outputs up to 10A, regulation not very good
- Increasing Regulator Current - you can boost 78xx regulator output with one power transistor
- Logic PSU with Over Voltage Protection - 5 volt regulated power supply for TTL and 74LS series integrated circuits, includes output overvoltage fault protection
- Low-drop regulator - outputs 5V at 1A, constructed from discrete components, in postscript file format
- 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
- Power Supply for Preamplifiers - gives +/-15V outputs and takes power from external AC power supply
- Power supply with +5V, +15V and -15V outputs
- Regulated 12 Supply - provides a regulated 12 volts at 0.5 amp to a load, built from discrete components
- 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
- Regulated Power Supplies - many designs, for 6V to 400V, both tube and transistor based designs
- 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
- 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
- Sam's Schematic Collection of various circuits - includes many regulated power supply circuits
- Simple 5V power supply for digital circuits
- Three terminal refulator with current boost option - for 5V output voltage
- Ultra Low Drop Linear Regulator - MOSFET based linear voltage regulator with a voltage drop of as low as 60 mV at 1 ampere, output 12V up to 3A, includes short-circuit crow-bar protection to guard the components against over-stress during accidental short at the output
- Voltage Regulator - simple regulated 12V power supply using one transistor regulator circuit
- Zener voltage regulators - not as good as 78xx's, but still fun
Adjustable
Dual polarity
Negative voltage generating circuits
CD player adaptors
Misc
Articles
- All About Switching Power Supplies - two practical design examples, pdf file
- A New Continuous-Time Model for Current-Mode Control - conference paper in pdf format
- Circuit trade-offs minimize noise in battery-input power supplies
- Comparator improves regulator's efficiency - UC384X family of current-mode PWM regulators requires a current shunt or some other component to develop a voltage proportional to the output current, in this example an extra amplifier reduces necessary voltage drop need so reduces losses
- Consider IGBTs over power MOSFETs at frequencies to 100 kHz - evaluating the performance of IGBTs and high-voltage power MOSFETs for switching applications requires a common set of applications and assumptions
- Current Doubler Topology: Myth and Reality
- Design Tips - information on transformer measuring and design and also general power supply design
- Effective MOS Transistors Drive Circuits For Bridge Converters
- Feedback isolation augments power-supply safety and performance - properly designed isolated feedback is crucial to maintaining safety on many power supply designs
- Finding the keys to flyback power supplies produces efficient design - quick tutorial on flyback-power-supply design may help clear out some of the cobwebs
- Friendly software eases power-supply design - free software from power-products vendors saves you time and effort when you are configuring and characterizing swoiched mode power-supply designs
- IC and capacitor improve isolated supply - many isolated power supplies typically use an optocoupler and a reference to provide feedback to a controller to maintain a constant output voltage, this uses different method to provide controlled output voltage
- Isolated Feedback Techniques for Power Supplies
- Leakage Inductance: Living With Leakage Elements in Flyback Converters - review of the magnetic and electric models of the two-winding and three-winding transformers
- LIER circuit helps power-supply efficiency - leakage-inductance, energy-recovery (LIER) circuit ecovers energy stored in the primary leakage inductance and delivers the recovered energy to one of the power supply's outputs
- Little ICs generate big voltages - ICs and small modules simplify the task of generating the high voltages for displays and their associated backlights
- Low-voltage power sources keep pace with plummeting logic and µP voltages
- Modify your switching-supply architecture for improved transient response - by taking a different approach to switching-supply design, you can develop an architecture that improves overall supply performance in critical transient specifications
- Power Converter Survives High-Energy, Low-Frequency Surges - high-energy, low-frequency surge transients can damage electronic circuits, unless the circuit configuration is equiped to handle this type of transient
- Powering New-Generation Microprocessors - there is pressure to abandon inefficient linear regulators on PC motherboards with switching power supplies
- Saturable bead improves reverse recovery - this circuit uses a saturable inductor bead to control the switching diode's reverse-recovery time and, therefore, to reduce EMI in swtiching power supply
- Simplified calculation of magnetic and electrical losses in unity power factor boost regulators
- Smart Solid-State Fuse Helps Designers Cure Boost-Converter Ailments - The challenge is to get desired load disconnect while retaining use of the humble catch diode and unadorned boost topology
- SMPS switch mode power supplies design - oftware tools and design examples
- Spice predicts differential conducted EMI from switching power supplies - not only can predict the exact EMI levels produced by a switched-mode power supply, but also can produce plots that allow you to easily evaluate your design and the effectiveness of the EMI filter
- Spreadsheet simplifies switch-mode power-supply flyback-transformer design - designing flyback transformers for switch-mode power supplies involves many calculations, this spreadsheet helps it
- Synchronous rectification aids low-voltage power supplies - synchronous rectifiers can improve switching-power-supply efficiency, particularly in low-voltage, low-power applications
- Switching converter uses planar magnetics - planar-magnetics technology is growing in popularity as a design option for dc-dc converters
- Switching-Mode Power Supply Design - A good power electronics circuit design hypertext with problem silving tips
- Switching-regulator design lowers noise to 100 µV - extending unconscionable amounts of bypass capacitors, ferrite beads, shields, Mumetal, and aspirin to ameliorate noise-induced effects is no longer the only way to tackle switching-regulator noise, there are nowadays low-noise ICs available
- Switching regulators demystified - Key to good design of switching-regulator circuits is a solid understanding of the fundamental theory of operation.
- Switching-regulator supply provides low-noise biasing for varactor diodes - Low-voltage systems often need a locally generated high voltage. Even for an application as noise-sensitive as varactor-diode biasing, a carefully planned switching-regulator-based design and layout can provide the necessary bias voltage.
- Tandem hookups enhance utility of dc/dc units - flexibility you can gain by connecting isolated, compact dc/dc converters in parallel or series allows low-cost, standard parts to meet system needs with minimal cost and space penalties
- The Use of Zetex E-Line Transistors in DC-DC Converters - application note which describes 8W fluorescent lap driver, simple DC/DC converter and xenon flash tube circuit, pdf format
- Troubleshooting and Repair of small Switchmode Power Supplies
- V2 Architecture Provides Ultra-Fast Transient Response in Switch Mode Power Supplies
Step-up converters
- 2 Watt Switching Power Supply - from 6V to 14V
- 6V to 12V Converter - can provide up to 800mA of 12V power from a 6V supply
- A low cost step-up converter - inputs 9-15 V and outputs 12-25V, maximum output power is 18V and 3A
- Battery booster delivers 75W - uses isolated DC/DC converter in a nonisolated configuration to boost a 48V battery voltage to 60V
- Battery-powered 5 V source - takes anything between 0.9 and 12 V and automatically steps it up or down to 3 or 5 V, at your discretion
- 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
- Boost converter generates three analog rails
- Coilless step-up converter yields dual outputs - provides regulated 5 and 3V supplies from a wide input range without the need for inductors
- 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
- DC to DC Converter - will produce a 85V voltage from +3V, usable for low power applications
- 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
- Flashgun Converter - can provide flash capacitor charge in 5 seconds, design note in pdf format
- Hex inverter makes low-cost switching regulator - simple and low-cost circuit converts 5V to 12V
- High power 12 V to 300 V invertor for high repeat rate medium power strobes
- 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
- Li-ion boost circuit uses no inductors - circuit to mainstain regulated 3.3V supply for portable applications
- Low-cost switcher converts 5 to 24V - low-cost, three-transistor low power boost switching regulator
- Panel meter power supply - isolated 9.1V 2-5 mA output from 8-30V input, in pdf format, text in Finnish
- 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
Step-down converters
- 3.3-V Supply Taps Power From The 12 V PCI Bus
- 5-to-1.8V Converter Works Without Magnetics
- 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
- 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%
- Buck regulator generates flexible VTT for PECL - circuit to generate output which can both source and sink current
- Circuit provides 1.5V, 7A bus termination
- 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
- 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
- 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
- Switched-capacitor regulator provides gain - switched capacitor idea to convers 12V to 3.3V or 5V
- The MIC4680 Switching Regulator - simple circuit which outputs +5V
- 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
- 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
Dual polarity output power supplies
Negative voltage generation
DC-DC converters with isolation
Mains powered switchers
Other switching circuits
Transformerless power supplies are very useful in some applications, but
remeber that eliminating the transformer eliminates the safety factor.
You should this type of power supply only if the circuit you want to power
has no external connections to anything else (unless they are properly
isolated from the rest of the circuit).
Line isolation is essential for safety with respect to electrical shock - no
part accessible to the user must be connected to either side of the power line.
A regular transformer provides this automatically.
Project pages for car PC power supplies
Power connector pinouts
General battery information
General charging circuits
Battery chargers fo NiCd batteries
Li-ion battery chargers
Lead-acid battery cargers
Combined power supplies and batery chargers
Battery discharging circuits
Battery backup circuits
Battery protection
Battery status sensors
Other battery circuits
NOTE: Most of the circuits have square wave output and are not suitable for driving sensitive electronicd equipments. The AC from those inverters can damage some equipments connected to them.
General articles
Circuits
UPS techology
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