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Voltage Regulator Circuits

Voltage Regulators:  #'s - A       B - D       E - K       L - Q       P - S      
T - Z

 

Last Updated: 09/06/2020 02:31 PM

Circuits Designed by Dave Johnson, P.E. :

Touch Switch 240VAC -  This is another capacitance based touch on/touch off switch, which can control power to a 200 watt 240vac load . . . Hobby Circuit designed by Dave Johnson P.E.-February, 2002

Ultra Low Power Human Finger Detector -  The circuit below seems to work well and averages a current drain of only 10 microamps from a lithium cell.  it uses a single CA4013 dual D flip/flop.  One section is wired as a pulse generator.  it applies 10us 10ma pulses to a LED inside a slotted optical sensor at a rate of about 50Hz.  The phototransistor in the second half of the sensor detects the pulses and sends a pulse to the data input of the second flip/flop in the 4013 package.  if there is nothing between the LED and the phototransistor, the inverting output of the 4013 remains low.Circuit Solution by David A. Johnson P.E.-May, 2006

Variable Isolated AC Voltage Spans 0VAC to 280Vac -  I designed and built this circuit about 25 years ago.  it came in handy for many projects that were powered from 120 VAC, 240 VAC and 277 VAC.  it provides complete isolation from the power line.  it uses two 1:1 isolation transformers that are wired in parallel. . . Circuit by David A. Johnson P.E.-July, 2000

Voltage Boost -  in this design a marginal AC to DC linear power supply provides a voltage boost, so it can maintain regulation at low line voltages.  The added components are wired at the AC input and the + DC output of an existing bridge rectifier circuit.  The components act as a full wave “charge pump” which will boost the DC output voltage across the main filter capacitor C3.  Without the boost circuit, when the AC line voltage drops to 105vac, the DC output voltage only reaches 11.5 volts, too low for a 12v voltage regulator. . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006

Voltage Boost to Series Regulator provided by Capacitor -  This circuit adds some capacitors and diodes to a traditional transformer type series regulator circuit to extend the normal operating range.  it can insure regulation during low line voltage conditions or it can squeeze a few more watts out of a plug-in-the-wall power adapter power supply . . . Hobby Circuit designed by David Johnson P.E.-January, 1998

Voltage Converters-0.5 to 6 Volts -  Conventional silicon transistors just can't operate at voltages less than about 0.7v.  Old germanium transistors could be used, but those are hard to find these days and most are rather large in size.  Some new n-channel MOSFET devices with very. . . Circuit by Dave Johnson P.E.-May, 2007 

Capacitance Proximity Switch
Draws very low power - Ideal for battery-powered applications
6 Models Available - Call 806-778-8407




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

Ultra Low Drop Linear Regulator -  The circuit is a MOSFET based linear voltage regulator with a voltage drop of as low as 60 mV at 1 ampere.  Drop of a fewer millivolts is possible with better...__ Electronics Projects for You

Ultra Low Power Human Finger Detector -  The circuit below seems to work well and averages a current drain of only 10 microamps from a lithium cell.  it uses a single CA4013 dual D flip/flop.  One section is wired as a pulse generator.  it applies 10us 10ma pulses to a LED inside a slotted optical sensor at a rate of about 50Hz.  The phototransistor in the second half of the sensor detects the pulses and sends a pulse to the data input of the second flip/flop in the 4013 package.  if there is nothing between the LED and the phototransistor, the inverting output of the 4013 remains low.  Circuit Solution by David A. Johnson P.E.-May, 2006

Ultra Simple Circuit Split DC Supply -  DC voltage "virtual earth" circuits __ Designed by Rod Elliott  ESP

UltraFast Linear Regulator Eliminates All Bulk Tantalum & Electrolytic Output Capacitors -  DN157 Design Notes __ Linear Technology/Analog Devices

Ultra-Low Dropout Regulator -  DN32 Design Notes__ Linear Technology/Analog Devices

UltraLow Noise Switching Power Supplies Simplify EMI Compliance -  DN316 Design Notes__ Linear Technology/Analog Devices

Ultra-low-noise low-dropout regulator achieves 6-nV/√Hz noise floor -  06/23/05  EDN Design Ideas:  LDO has ultralow-noise output Design by Ken Yang, Maxim Integrated Products Inc, Sunnyvale, CA

Ultrathin dual 2.5A or single 5A μModule regulator fits on the backside of PCBs, allowing space on the topside for digital ICs -  EDN Design Ideas:  09/29/2016    This versatile DC-DC excels where height is limited and multiple ganging options are advantageous Design by LTC Design Note

Understanding and Applying the LT1005 Multifunction Regulator -  Linear Technology AN1 __ Designed by Jim Williams - Aug 1st, 1984

Universal DC-to-DC Converter -  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 __ Designed by Andy Collison

Universal Input 48W PFC Application -  The LT3798 is a constant voltage/constant current isolated flyback controller that combines active power factor correction (PFC) with no opto-coupler required for output voltage feedback into a single-stage converter.  A LT3798 based design can achieve a power factor of greater than 0.97 by actively modulating the input current, __ Linear Technology/Analog Devices App Note, Dec 5th 2011

Universal Power Supply -  Linear regulators like LM317, LM337, 78xx and 79xx, Zener diodes (1.3W) and reference diodes (e.g., LM336) are quite inexpensive and widely available.  So you can use these liberally in power supplies.  Sometimes...__ Electronics Projects for You

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

Universal Voltage Regulator Board -  Digital/Analog USB Data Logger, Pt.3__ SiliconChip

Use a 555 timer as a switch-mode power supply -  14-Nov-02 EDN Design Ideas:  Most switch-mode power supplies rely on a PWM (pulse-width-modulated] output that is controlled via voltage feedback.  A 555-timer IC can inexpensively perform PWM.  The circuit in Figure 1 shows how to turn a 555 PWM circuit into an switch-mode power supply with only one simple equation.  The design uses two 555s Design by Aaron Lager, Masterwork Electronics, Rohnert Park, CA

Use a Three-Phase Rectifier & Voltage Reducer for Offline Single-Phase Supplies -  EDN-Design ideas -- 04/06/12    Missing diodes create gaps to allow voltage reduction. Design by JB Castro-Miguens, Cesinel, Madrid, Spain; C Castro-Miguens, University of Vigo, Spain; M Pérez Suárez, University of Vigo, Spain; and A Abal Pena, Tekplus, Vigo, Spain

Use a TL431 shunt regulator to limit high AC input voltage -  10/25/07  EDN Design Ideas:  This circuit clamps input-ac voltages to levels safe for the operation of the power MOSFET in an SMPS Design by Todor Arsenov, STMicroelectronics, Prague, Czech Republic

Use an LM317 as 0 to 3V Adjustable Regulator -  10/02/08  EDN Design Ideas:  LM317 acts as an adjustable regulator Design by Vladimir Rentyuk, Modul-98 Ltd, Zaporozhye, Ukraine

Use Two 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).  SEPIC offer lower input-curre Design by Goran Perica, Linear Technology, Milpitas, CA

Use Two Reference Voltages to Improve Hysteresis Accuracy -  01/07/10  EDN Design Ideas:  increase the hystereis of your comparator by switching between two reference voltages Design by Marián Stofka, Slovak University of Technology, Bratislava, Slovakia

Using a PC power supply as a benchtop power supply -  This ATX PS board has leads for +5 (RED) , -5 (WHiTE) , +12 (YELLOW) , -12 (BLUE) volts, Ground (BLACK) and switch (GREEN).  Dell power supplies manufactured between 1996 and 2000 do not follow the industry standard pinout and color codes.  The fan has also been unplugged for better viewing.  Since this PS was converted for use in the logic and robotics labs, the selected voltages  __ Designed by Andy Batts

Using the LM317T to Regulate Voltage -  Use an LM317T to regulate voltage in renewable energy projects.   __ Designed by REUK-Renewable Energy UK website

Variable 3 to 24 Volt/3 Amp Power Supply -  This regulated power supply can be adjusted from 3 to 25 volts and is current limited to 2 amps as shown, but may be increased to 3 amps or more by selecting a smaller current sense resistor (0.3 ohm).  The 2N3055 and 2N3053 transistors should be mounted on suitable heat sinks and the current sense resistor should be rated at 3 watts or more.  Voltage regulation is controlled by 1/2 of a 1558 or 1458 op-amp.  The 1458 may be substituted in the circuit below, but it is recommended the supply voltage to pin 8 be limited to 30 VDC, which can be accomplished by adding a 6.2 volt zener or 5.1 K.  Page has several circuits, please scroll to find this one.   __ Designed by Bill Bowden

Variable DC Power Supply -  This power supply is based on the LM317 Variable Regulator.  The input of the regulator needs to be around 28 Volts DC and it will output a DC voltage from 1.25vdc to 25 vdc.  To adjust the output voltage simply turn the 5k ohm pot.  The regulator will supply 1.5 amps of current . . . Copyright 2000 Randy Linscott 

Variable DC Power Supply -  Voltage range: 0.7 - 24V; Current limiting range: 50mA - 2A __ Contact Flavio Dellepiane, fladello @ tin.it

Variable DC Power Supply -  A variable power supply with adjustable voltage and current outputs made with the L200 regulator.   __ Designed by Andy Collison

Variable Dual LAB Power Supply -  Up to 800mA (typical) output current at +/-25V.   __ Designed by Rod Elliott  ESP

Variable HV power supply employs photovoltaic optocoupler -  07/14/14 EDN Design Ideas:  This unusual topology saved the day when a higher-voltage variable supply was needed.   Design by sajjad Haidar

Variable Isolated AC Voltage Spans 0VAC to 280Vac -  I designed and built this circuit about 25 years ago.  it came in handy for many projects that were powered from 120 VAC, 240 VAC and 277 VAC.  it provides complete isolation from the power line.  it uses two 1:1 isolation transformers that are wired in parallel. . . Circuit by David A. Johnson P.E.-July, 2000

Variable Laboratory DC Power Supply -  Voltage range: 0.7, 24V Current limiting range: 50mA, 2A A Variable DC Power Supply is one of the most useful tools on the electronics hobbyist's workbench.  This circuit is not an absolute novelty, but it is simple, reliable, "rugged" and short-proof, featuring variable voltage up to 24V and variable current limiting up to 2A.  Well suited to supply the circuits shown in this website.  You can adapt it to your own requirements as explained in the notes below.  __ 

Variable load tests voltage sources -  07/19/01 EDN Design Ideas:  The circuit in Figure 1 serves as a variable, current-sink load for testing voltage sources.  You use digital commands to set the load current of the device under test over a wide range, independent- ly of the device under test's output voltage.  The circuit comprises an AD558 DAC, IC 1, which provide as a reference voltage at Point A Design by Michele Frantisek, Brno, Czech Republic

Variable Power resistor load -  very useful and simple item __ Designed by Thomas Scherrer OZ2CPU

Variable Power Supply using a Fixed-Voltage Regulator IC -  A voltage regulator (also called a ‘regulator’) with only three terminals appears to be a simple device, but it is in fact a very complex integrated circuit.  it converts a varying...__ Electronics Projects for You

Variable Power Supply using Fixed Regulator -  This is a similar power supply that I used to power my FM Transmitter.  After suffering long problems with mains hum, this design using a pI filtered C-L-C approach.  This circuit offers excellent ripple rejection.   __ Designed by David Celestin

Variable Power Supply with Digital Control -  The most frequently used device in electronic workshops and laboratories is a universal power supply that provides a variable, fluctuation-free output.  Here we present a variable power supply with digital control...__ Electronics Projects for You

Variable Power Supply, 1-30V @ 1.5A -  This is a simple, but low-ripple power supply, 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 amps which is also sufficient for most of your tinkering __ Designed by Tony van Roon  VA3AVR

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Got Designs?
Please eMail
if you want me to link to and/or post your original design Thanks.


Voltage Regulators:  #'s - A       B - D       E - K       L - Q       P - S       T - Z


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