Voltage Regulator Electronic Circuits

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. :

0.5v to 6v Voltage Converter - 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 . . . Hobby Circuit designed by David Johnson P.E.-May, 2007

0VAC to 280VAC Variable Isolated AC Voltage - 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 . . . Hobby Circuit designed by David Johnson P.E.-July, 2000

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. I'd 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-24v AC & DC Day/Night Switch - The circuit uses a bridge rectifier circuit to convert AC into DC. A 12v zener diode limits the operating voltage of the circuit to 12v. A tiny Schmitt trigger inverter and a phototransistor detects the ambient light intensity. if there is sufficient light, the inverter disables a push-pull oscillator circuit . . . Hobby Circuit designed by David A. Johnson P.E.-March, 2012

240VAC to 5VDC Power Supply - This is simple way to power some 5v logic from a 240vac source. if a 120vac power adapter is used, the circuit will also work for 120vac power lines. . . Circuit by David Johnson P.E.-February, 2002

5+V Classic Linear Supply using 6.3VAC Transformer - A classic method for producing a regulated +5v DC supply is shown below. This circuit consists of an iron core transformer, a bridge rectifier, a filter capacitor and a voltage regulator. Many people are tempted to use a very popular 6.3v transformer . . . Hobby Circuit designed by Dave Johnson P.E.-February, 2009

9v Battery Eliminator - if you use 9v battery powered devices for long periods of time, you may get tired of constantly changing batteries. The circuit below can be wired into any 9v battery powered device, drawing power from an external AC to DC power adapter. I designed the circuit. . . Circuit by David Johnson P.E.-December, 2009

AC to DC (240v to 5v)Power Supply - This is simple way to power some 5v logic from a 240vac source. if a 120vac power adapter is used, the circuit will also work for 120vac power lines . . . Hobby Circuit designed by David A. Johnson P.E.-February, 2002

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:

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

AM Modulator has high bandwidth - 09/11/98 EDN Design Ideas: (FILE
has many circuits, scroll to find this one) The simple circuit in Figure 1 is an add-on modulator that converts the output of a continuous-wave (CW] source to either an amplitude-modulation (AM] or a suppressed-carrier-modulation (SCM] format. Because the circuit has unity gain and 50 Ohm input and output impedances, the CW generator's Design by MJ Salvati, Flushing Communications, Flushing, NY

AMC 2V & 3.3V Hot Swap Controller Application with Digital Monitoring - The LTC4222 Hot Swap controller allows two power paths to be safely inserted and removed from a live backplane. Using external N-channel pass transistors, board supply voltages and inrush currents are ramped up at an adjustable rate. An i2C interface and onboard ADC allows for monitoring of current, voltage and fault status __ Linear Technology/Analog Devices App Note, Mar 26th 2010

Amperage Booster for 78xx's - Volt regulators such as the LM708, and LM317 series (and others) sometimes need to provide a little bit more current then they actually can handle. if that is the case, this little circuit can help out. A power transistor such as the 2N3772 or similar can be used (See the project on the 3-part variable power supply) __ Designed by Tony van Roon VA3AVR

Amperor 12 Volt LCD TFT Stabiliser - A 12V regulator for use with flat screen televisions and more. __ Designed by REUK-Renewable Energy UK website

An Alarm Power Supply with Battery Back-up - Power Supply Circuits: This Power Supply is suitable for the Modular Burglar Alarm. However, it has other applications. it is designed to provide an output of 12-volts, with a current of up to 1-amp. in the event of mains failure, the back-up battery takes over automatically. When the mains is restored, the battery recharges. __ Designed by Ron J.

An Output Adjustable Flyback Converter - A high voltage step-up DC power supply using adjustable flyback conversion. __ Designed by Simon Oh

AN106 - Instrumentation Circuitry Using RMS-to-DC Converters - Linear Technology AN106 __ Designed by Jim Williams - Feb 21st, 2007

AN124 - 775 Nanovolt Noise Measurement for A Low Noise Voltage Reference - Linear Technology AN124 __ Designed by Jim Williams - Jul 3rd, 2009

AN126 - 2-Wire Virtual Remote Sensing for Voltage Regulators - Clairvoyance Marries Remote Sensing - Linear Technology AN126 __ Designed by Jim Williams - Oct 1st, 2010

AN2 - Performance Enhancement Techniques for Three-Terminal Regulators - Linear Technology AN2 __ Designed by Jim Williams - Aug 2nd, 1984

AN25 - Switching Regulators for Poets: A Gentle Guide for the Trepidatious - Linear Technology AN25 __ Designed by Jim Williams - Sep 2nd, 1987

AN70 - A Monolithic Switching Regulator with 100µV Output Noise - Linear Technology AN70 __ Designed by Jim Williams - Oct 1st, 1997

AN83 - Performance Verification of Low Noise, Low Dropout Regulators - Linear Technology AN83 __ Designed by Jim Williams - Mar 1st, 2000

AN85 - Low Noise Varactor Biasing with Switching Regulators: Vanquishing Villainous Vitiators Vis-à-Vis Vital Varactors - Linear Technology AN85 __ Designed by Jim Williams - Aug 1st, 2000

Another solar panel regulator - This is a switching shunt regulator which is very simple and reliable, but does not regulate as smoothly as the one above and has no deep-discharge protection. it was built for a yacht. __ Designed by Manfred Mornhinweg

Auto-Adjustable Regulators Power Pentium Pr - 12/07/95 EDN Design Ideas: Powering intel’s next-generation Pentium Pro (P6) µ proves to be a nontrivial task due to both the greater-than-30W load and the need to finely adjust input voltage level on a chip-by-chip basis. The AA32A family of switching regulators from Astec America Design by Maury WrightAstec America Inc, Carlsbad, CA -- 12/07/95

Automatic Local Sensing Improves Regulation - 1/04/96 EDN Design Ideas: A power supply usually needs to provide a regulated voltage across a load, but there is always some voltage drop across the conductors that carry the current to the load. Two common techniques help the supply to achieve the proper voltage across the load. One Design by Jimmie D Felps, Hewlett-Packard Colorado Springs, CO

Automatic Trickle Charger - Scroll down to find this circuit. Here is the schematic for the automatic charger I have been using for my kids' battery cars. The charger is a small molded unit that probably doesn't supply more than an amp and this circuit would have trouble with much more. No current limit is provided by this circuit __ Contact: Charles Wenzel of Wenzel Associates, Inc.

Automotive 5V Regulator with Cold Crank Capability - The LTC3115-1 is a high voltage monolithic synchronous buck-boost DC/DC converter. its wide 2.7V to 40V input and output voltage ranges make it well suited to a wide variety of automotive and industrial applications. A proprietary low noise switching algorithm optimizes efficiency with input voltages that are above, below or even equal to the output voltage and ensures seamless transitions between operational modes. __ Linear Technology/Analog Devices App Note, Dec 5, 2011

Automotive 9V-19.5Vin to 5V at 1A with 60V Transient Protection & 1.7MHz Switching Frequency - The LT3682 is a 1A monolithic buck switching regulator that accepts input voltages from 3.6V to 36V and transients up to 60V. it features an adjustable and synchronizable switching frequency from 250kHz to 2.2MHz. it also has the ability to monitor the current flowing through the external catch diode, thus providing an extra level of protection against output fault conditions over the entire operating frequency range, regardless of input voltage__ Linear Technology/Analog Devices App Note, Jul 22, 2010

Automotive Switching Regulators Get Input-Transient-Voltage Protection - 01/24/08 EDN Design Ideas: A simple scheme protects switching regulators against 50V voltage transients in automotive applications Design by Kevin Daugherty, National Semiconductor, Novi, MI

Autoranging simplifies hardware & software - 07/22/99 EDN Design Ideas: A natural approach to autoranging is to use an inverting op amp and switch in one of N feedback resistors at a time for a gain of A=-RF/RO (Figure 1). However, the inverting configuration suffers from low input impedance of Zinn=RO because the negative input is at virtual ground. Design by Dana Romero, Phonex, Midvale, UT

Autoranging True RMS-to-DC Converter - A programmable gain amplifier (LTC6910-2) and a window comparator (LTC6700-1) and some control logic creates a wide dynamic range RMS to DC converter. The comparator monitors the DC output and signals whether to increment or decrement the gain to maintain a predetermined output voltage range. Knowing the output DC voltage and the gain setting can determine the True RMS amplitude of the signal being monitored__ Linear Technology/Analog Devices App Note, Mar 16, 2010

Autoreferencing nulls out sensor errors - 24-Jan-02 EDN Design Ideas: The autoreferencing circuit in Figure 1 nulls out the error of a sensor, such as a pressure transducer, at its reference level-for example, at ambient pressure. The circuit is an analog-digital-feedback control system that uses a digitally programmable potentiometer to provide the variability Design by Chuck Wojslaw, Catalyst Semiconductor, Sunnyvale, CA

Autotransformer regulator inverts 12V to produce 12V - 08/01/1997 EDN Design Ideas: You can create a dc/dc regulator with an internal switching MOSFET that inverts 12V to produce an output of 200 mA at 12V. The IC is a high-efficiency device whose low quiescent current (120 µA maximum) is the product of a CMOS process that limits the absolute-maximum input-to-output voltage to 21V. Design by Dana Davis

Auxiliary 12V Flyback SMPS - Finally a use for those extra ferrites! __

Avoid problems with multiple DC-DC converters - EDN Design Ideas: 05/05/2014 improve DC-DC converter design and application, and avoid potential problems with this synchronization circuit Design by Avago Tech Note

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