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Power Supplies:  DC to DC / Switch Mode and DC to DC Converters
Boost,    Buck,    Buck-Boost,    Switchmode

Power Supplies -- Main Page           Converters -- Main Page
DC to DC:  #'s - A       B - D       E - L       M - R       S - Z
 

Last Updated: October 18, 2017 05:04 AM

Circuits Designed by Dave Johnson, P.E. :

 200Mhz-400Mhz Voltage Controlled Oscillator (VCO) - If you need a clean emitter coupled logic   (ECL) type signal between 200MHz and 400MHz this circuit works fine.  It uses four voltage-controlled capacitors to change the frequency. . . Circuit by Dave Johnson P.E.-March, 1999

 24v NiMH Battery Charger using a 12v Solar Panel  - A while back I received an email from a guy in the UK.  He wanted to use a small solar panel, designed to charge 12v lead acid batteries, but use it to charge a 24v battery pack.  His 24v battery pack used 20 AA size NiMH cells.  He went on to explain that his 20 cell NiMH battery pack was used very infrequently . . . Hobby Circuit designed by Dave Johnson P.E.-October, 2011

 300v Peak to Peak Signal Generator - This circuit converts a square wave signal to a +-150 volt output signal with fast 100nS rise and fall times. . . Circuit by David A. Johnson P.E.-June, 2000


Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

12 Volt 20 Amp Power Supply -  A 12 Volt high current 20 Amp power supply.  The output voltage is variable from 12.2 Volt to 14.4V so can be set for any device requiring voltage and current in that range.  This PSU uses an LM723 as the regulator, 4 parallel connected outboard pass transistors and has current limiting above 25 amps __ Designed by Andy Collison

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 to30 amps __ Designed by Andy Collison

12 Volt Alarm Power Supply -  A 12 Volt power suppiled designed for Ron's Modular Burglar Alarm.  However, being a popular supply voltage this circuit will have many other uses as well.   __ Designed by Andy Collison

12 Volt DC Power Supply -  This is a simple low-cost 50W off-line switching power supply, which can be used for home projects or to learn operation of flyback converters.  it can work over a universal AC line input range 90-264 VAC and provides a 12VDC output at more than 4A load.  Line and load regulation is better than 0.5%. (added 11/07)  __ Designed by Lazar Rozenblat

12 Volt Power Supply -  Please operate caution when building this power supply.  it is run on standard 117 ac current and under right circumstances 117 ac can kill you.  Use a plastic enclosure if possible to decrease chances of short-circuiting.  Don't use power  supply if it's wet, and never run it without specified fuse.   __ Designed by Andy Wilson

125Khz LC Oscillator -  This circuit adds more invertors in parallel to deliver more power.  it is similar to CMOS iNVERTERS FORM 125KHZ OSCiLLATOR.  Please note that the values shown are for 125KHz.. . . Circuit by Dave Johnson P.E.-March, 2002

125KHZ Medium Power Ocsillator -  This circuit is similar to MEDiUM POWER 125KHZ OSCiLLATOR but adds even more inverters in parallel to deliver yet more power.  The values shown are for 125KHz . . . Hobby Circuit designed by David Johnson P.E.-March, 2002

125Khz Oscillator from CMOS Inverters -  This circuit inverts the LC components so the inductor is grounded.  Two inverters are needed to produce the needed oscillation.  Again, the values shown set the frequency at 125KHz but can be changed to produce other frequencies. . . Circuit by David Johnson P.E.-March, 2002

125khz Oscillator with Medium Power -  This circuit adds even more inverters in parallel to deliver yet more power.  The values shown are for 125KHz . . . Hobby Circuit designed by David A. Johnson P.E.-March, 2002

125Khz Ultra Pure Sine Wave Signal Source -  For some RFID systems operating at 125KHz, a very low distortion signal source reference is needed.  The circuit shown on this page produces a 10-volt peak-to-peak signal into a 50-ohm load, with a distortion of only 0.01% . . . Hobby Circuit designed by Dave Johnson P.E.-February, 2002

12V to +/-30V DC to DC Converter -  This is a DC to DC converter for car power amplifier.12V input generates +30V and -30V output for preamp or power amplifiers.  Circuit uses SG3525 iC, MOSFETs and switching power supply__ 

12v to 19v Laptop Power Supply (Concept) -  Concept Only.  I have a big screen HP laptop computer.  The large brick size AC to DC power supply is rated at 19.2v and 9.5 amps, which is about 180 watts.  id like to be able to use the thing in my car.  I looked into a 12v car adapter for it but never really found one that I liked.  Most were underpowered.  The other option was to use the existing AC to DC adapter and run it off power from a 12v to 120vac inverter. . . Circuit by David Johnson P.E.-July, 2009

12V to 28V DC-DC Converter with LM2585 -  This boost regulator is for those times when you have a 28v relay, but want to use it with a 12v source.  The circuit is built around the National Semiconductor LM2585, and uses the energy stored in an inductor to boost the 12v to 28.  Output voltage can be varied by adjusting the ratio of resistor values on the feedback pin.  __ 

12V to 9V with a LM317 -  This little circuit uses a LM317 variable voltage regulator to adjust the input voltage down to +9 volt, or whatever else you need.  Just a solid basic circuit without bells and whistles. 
You can do with a 10uF capacitor for C1 if your battery is close to this circuit.  if it is located more than 3 feet increase the value to 100uF or above.   __ Designed by Tony van Roon  VA3AVR

12v Touch Switch Exciter Circuit -  This circuit is designed to generate a 20KHz pseudo sine wave signal that can power about 50 remote touch activated switch circuits.    it can support a cable length of about 2500 feet.    A typical remote switch circuit is also shown as well as a receiver circuit for those switches.. . . Circuit by Dave Johnson P.E.-February, 2002

12V-24Vin to 5VoutAT1.4A Monolithic Isolated Flyback Converter (No Opto or Third Winding) -  The LT3575 is a monolithic switching regulator specifically designed for the isolated flyback topology.  No third winding or opto-isolator is required for regulation.  The part senses the isolated output voltage directly from the primary side flyback waveform.  A 2.5A, 60V NPN power switch is integrated along with all control__ Linear Technology/Analog Devices App Note, Jan 27th 2011

12V-24Vin to 5VoutAT350mA Monolithic Isolated Flyback Converter (No Opto or Third Winding) -  The LT3574 is a monolithic switching regulator specifically designed for the isolated flyback topology.  No third winding or opto-isolator is required for regulation.  The part senses the isolated output voltage directly from the primary side flyback waveform.  A 0.65A, 60V NPN power switch is integrated along with all control__ Linear Technology/Analog Devices App Note, Jan 27th 2011

12V-24Vin to Four Output 12VAT120mA Monolithic Isolated Flyback Converter (No Opto or Third Winding) -  The LT3575 is a monolithic switching regulator specifically designed for the isolated flyback topology.  No third winding or opto-isolator is required for regulation.  The part senses the isolated output voltage directly from the primary side flyback waveform.  A 2.5A, 60V NPN power switch is integrated along with all control__ Linear Technology/Analog Devices App Note, Jan 27th 2011

12Vin to 5V AT 25A using Very Low DCR Current Sense -  The LTC3866 is especially well suited to low voltage, high current supplies because of a unique architecture that enhances the signal-to-noise ratio of the current sense circuit.  This allows it to operate with the small sense signals produced by very low DCR, 1mΩ or less, inductors, which are used to improve power efficiency in high current supplies.  The improved SNR minimizes jitter due to the switching noise, which could corrupt the signal.  The LTC3866 can sense a DCR value as low as 0.2mΩ with careful PCB layout__ Linear Technology/Analog Devices App Note, Mar 29th 2012

13.8 Volt, 20 Ampere linear power supply -  A semi-traditional power supply for communication equipment, using negative-rail regulation with grounded pass transistors in a configuration that gives some unique advantages. __ Designed by Manfred Mornhinweg

13V-30Vin to +/-5VAT500mA Monolithic Isolated Flyback Converter (No Opto or Third Winding) -  The LT3575 is a monolithic switching regulator specifically designed for the isolated flyback topology.  No third winding or opto-isolator is required for regulation.  The part senses the isolated output voltage directly from the primary side flyback waveform.  A 2.5A, 60V NPN power switch is integrated along with all control__ Linear Technology/Analog Devices App Note, Jan 27th 2011

15V/ 28V 4A Transmitter Power Supply -  Schematic + Notes for this Power supply used for professional FM broadcasting transmitter.  __ 

160 Volt, 3 Ampere DC Motor power supply -  A very compact, efficient and simple off-line buck regulator. __ Designed by Manfred Mornhinweg

1A Variable Regulated Power Supply -  A 'must-have' for the experimenter. __ Designed by Peter Parker VK3YE

1-NiCd Cells Drives Op Amp -  12/05/96 EDN Design Ideas:  Low-supply-voltage op amps, such as the LMC6582 and LMC6681 families, feature rail-to-rail i/O with a gain-bandwidth product greater than 1 MHz operating from just 1.8V.  Although impressive, this voltage is not low enough to power these amps using a single alkaline or NiCd/NiMH cell, which have typical voltages of 1.25 to 1.5V.  it is rather tempting to bridge this gap by designing a DC/DC converter __ Circuit Design by Alexander Belousov, Rego Park, NY

1-resistor improves V2 converter -  08/15/97 EDN Design Ideas:    Step-down switching regulators commonly provide myriad digital-circuit voltages that range from traditional logic voltages of 5 and 3.3V to processor-core voltages of 1.8V and below.  The main advantage of these regulators __ Circuit Design by Dimitry Goder, Switch Power Inc, San Jose, CA

1-Transistor FM Transmitter -  A truly minimalist circuit.  Performance is relatively poor and stability is a problem.  Q1 modulates the signal and acts as an oscillator.  L1 and C5 determine the frequency.  Decrease C5 for a higher frequency and vice-versa.  __ 

2 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

2 AA Cells replace 9V Battery Extend Operating Life -  DN63 Design Notes__ Linear Technology/Analog Devices

2 Cores Marry, Make Swinging Choke -  05/11/95 EDN Design Ideas:  Designing an output choke for a switch-mode power supply that must operate over large load variations can be problematic.  if you design the inductor for the maximum load the power converter will see, the inductance will be below the critical inductance required at light load.  This inadequate inductance will cause the voltage on the output capacitor to peak up, resulting in increased ripple on the output __ Circuit Design by Vincent Spataro, GEC Marconi Electronic Systems Corp, Wayne, NJ

2 Phases to Cut Current & Improve EMI -  11/12/09 EDN Design Ideas:  in DC/DC-converter applications in which the input voltage may be lower or higher than the output voltage, you can use either a flyback converter or a SEPiC (single-ended-primary-inductor converter).  SEPiCs offer lower input-curre __ Circuit Design by Goran Perica, Linear Technology App Note, Milpitas, CA

2 Transistor FM Transmitters -  While there are a plethora of similar 2-transistor schematics available, this one is above average.  A major improvement overlittle 1-transistor circuit that we've discussed previously, this transmitter consist of two stages.  first transistor is used to amplify audio, __ 

2.5V to 36V Input, 12V/1A Output SEPIC Converter (Automotive 12V Regulator) -  The LT3759 is a wide input range, current mode, DC/DC controller which is capable of regulating either positive or negative output voltages from a single feedback pin.  it can be configured as a boost, SEPiC or inverting converter.  The LT3759 drives a low side external N-channel power MOSFET.  An internal LDO regulator draws__ Linear Technology/Analog Devices App Note, Sep 22, 2011

2.7V to 4.2V to-5V at 90mA & 4.6V at 100mA AM OLED Power Supply -  LT3582 are dual DC/DC converters with positive and negative outputs.  The positive output voltage can be set between 3.2V and 12.775V in 25mV steps.  The negative output voltage can be set between 1.2V and 13.95V in 50mV steps.  Optional i2C Programming__ Linear Technology/Analog Devices App Note, .Mar 24th 2010

20 Amp regulatable power supply New Design -  This is an easy to make power supply which has stable, clean and regulatable output voltage.  By using two 2N3055 transistors we become more than 2 times the amount of amps then the power supply delivers, making it real though to brake ;).  Although you could use this design to deliver 20 amps (with some modifications, see below page) , I did not needed such much power.  Make sure you mount them on a huge heat sink, as the 2N3055 transistors can get very hot at full load.  Also use thick wires.   __ Designed by Guy Roels ON6MU

200Mhz-400Mhz Voltage Controlled Oscillator (VCO) -  if you need a clean emitter coupled logic (ECL) type signal between 200MHz and 400MHz this circuit works fine.  it uses four voltage-controlled capacitors to change the frequency. . . Circuit by Dave Johnson P.E.-March, 1999

20-36Vin to 12VoutAT16A 2-Phase Low Noise EN55022B Compliant uModule Power Supply -  The LTM4613 is a complete, ultralow noise, 8A switch mode DC/DC power supply.  included in the package are the switching controller, power FETs, inductor and all support components.  Operating over an input voltage range of 5V to 36V, the LTM4613 supports an output voltage range of 3.3 V to 15V, set by a single external resistor.  Only bulk input and output capacitors are needed to finish the design__ Linear Technology/Analog Devices App Note, Apr 25th 2011

220V Non Dimming Ballast -  Efficient fluorescent lamps and magnetic ballasts have been the standard lighting fixture in commercial and industrial lighting for many years.  Several lamp types, rapid start, high output, and others are available for cost effective and special applications.  This user guide covers operation and development details of the non-dimmable version of our fluorescent ballast for operating a variety of lamps that are available today.   __ Designed by AT89RFD-10 / EVLB002

24V 12V DC DC Converter -  Find out how you can use a 24V battery (bank) to power 12V devices.   __ Designed by REUK-Renewable Energy UK website

24v NiMH Battery Charger using a 12v Solar Panel  -  A while back I received an email from a guy in the UK.  He wanted to use a small solar panel, designed to charge 12v lead acid batteries, but use it to charge a 24v battery pack.  His 24v battery pack used 20 AA size NiMH cells.  He went on to explain that his 20 cell NiMH battery pack was used very infrequently . . . Hobby Circuit designed by Dave Johnson P.E.-October, 2011

24Vin to 1.2Vout AT 15A using Inductor DCR Sensing to Minimize Solution Size & Cost -  This circuit shows a typical application of the LTC3613, configured for DCR sensing in a high step-down solution, 24V to 1.2V, and synchronized to a 350kHz external clock.  __ Linear Technology/Analog Devices App Note, Jun 29th 2012

24Vin to 5VoutAT0.7A Monolithic Isolated Flyback Converter (No Opto or Third Winding) -  The LT3573 is a monolithic switching regulator specifically designed for the isolated flyback topology.  No third winding or opto-isolator is required for regulation.  The part senses the isolated output voltage directly from the primary-side flyback waveform.  A 1.25A, 60V NPN power switch is integrated along with all control__ Linear Technology/Analog Devices App Note, Jan 27th 2011

26V-to-5000V DC-DC Converter -  This circuit can provide 5, 000 VDC from 26 VDC.  This circuit has ripple of under 0.01% due to Voltage-doubling capacitors.  As sinusoidal oscillator, a 2N217 transistor is used.  The diode and the capacitors at the output stage should be of high voltage type.  __ 

28V Dual Tracking Bipolar Supply with Outputs from 5V to 25V -  The LTC3260 is a low noise dual polarity output power supply that includes an inverting charge pump with both positive and negative LDO regulators.  The charge pump operates over a wide 4.5V to 32V input range and can deliver up to 100mA of output current.  Each LDO regulator can provide up to 50mA of output current.  The negative LDO post regulator is powered from the charge pump output.  The LDO output voltages can be adjusted using external resistor dividers__ Linear Technology/Analog Devices App Note, Apr 19th 2012

2-Phase Boost Converter Delivers 10W from a 3mm x 3mm DNF Package -  DN354 Design Notes__ Linear Technology/Analog Devices

2-Step Power Conversion: Portable Power for the Future -  Design Solutions 8 Design Notes__ Linear Technology/Analog Devices

2-Transistor Amplifier -  it has been interesting analyzing these radios.  You have to give the Japanese credit for even making a radio that can drive a speaker with only 2 transistors! Basically, the first transistor (Q1) performs double-duty.  it first acts as an RF amplifier, with some of the signal being fed back to the antenna coil to provide some regeneration for better selectivity and sensitivity __ Designed by schematic and circuit description were provided Ronald Rissel

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DC to DC:  #'s - A       B - D       E - L       M - R       S - Z

 


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