Electronic Circuits and electronic circuits, electronic schematics plus an extensive resource for hobbyists, inventors and engineers

DiscoverCircuits.com has links to 45,000+ electronic circuits, cross-referenced
into 500+ categories.    We have searched the web to help you find quick design ideas.

HOME Schematics Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches
Welcome to DiscoverCircuits.com - online since 2002

See Media Kit for
Advertising Opportunities

Attention Designers:  Please alert us by eMail if we have linked to sites
where your original material has been copied without your permission.
We will change to the LINK to your site.  
Thank you.

 


Opto-Isolator Coupler Circuits
Opto Isolators:   #'s - N      M - Z
 

Last Updated: October 18, 2017 05:04 AM

Circuits Designed by Dave Johnson, P.E. :

0.5v Negative Supply -  Although not very efficient, this simple circuit, consisting of two LEDs and a photo diode, generates a negative voltage with a current level of a couple milliamps.  It is ideal for supplying a negative rail to low power “rail to rail” op amp circuits, . . . Circuit by David Johnson P.E.-July, 2006

2-12v Battery Isolator Circuit with a LTC4412 -  Has just announced a neat little chip (LTC4412).  It has been designed to be used in conjunction with an external P-channel power FET, to form an ideal diode function with a very low 0.05v voltage drop.  The chip monitors the voltage on eit . . . Hobby Circuit designed by David Johnson P.E.-August, 2008

Generate 0.5v Negative Supply -  A while back someone needed a simple way to generate a negative 0.5v supply from a conventional transformer type AC to DC power supply.  The circuit below uses a couple schottky diodes and a filter capacitor to perform the feat . . . Hobby Circuit designed by David Johnson P.E.-July, 2011

Negative 0.5 Volt Supply -  This simple circuit consists of two LEDs and a photo diode.  It generates a negative voltage with a current level of a couple milliamps.  It is ideal for supplying a negative rail to low power “rail to rail” op amp circuits, which need to have a true zero volts output.  Note:  This circuit is not particularly efficient . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006


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

0.5v Negative Supply -  Although not very efficient, this simple circuit, consisting of two LEDs and a photo diode, generates a negative voltage with a current level of a couple milliamps.  It is ideal for supplying a negative rail to low power “rail to rail” op amp circuits,. . . Circuit by David Johnson P.E.-July, 2006

2-12v Battery Isolator Circuit with a LTC4412 -  Has just announced a neat little chip (LTC4412).  It has been designed to be used in conjunction with an external P-channel power FET, to form an ideal diode function with a very low 0.05v voltage drop.  The chip monitors the voltage on either . . . Hobby Circuit designed by David Johnson P.E.-August, 2008

Analog Opto Isolator -  This is a circuit to use a standard, low quality opto isolator to transfer an analogue signal with reasonable linearity and without complicated feedback loops to monitor and linearise it.  The circuit was designed to interface a mains driven thryristor motor controller to low voltage analogue circuitry.  In this application you could isolate the thyristor controller with a transformer and earth one side of the motor, but you still have a potentially high voltage situation if there is a wiring fault or component failure.  Also motors and thyristor controllers are potentially good generators of noise: in a system which used several motor controllers it was considered essential to isolate the input signal!  __ Designed by Richard Torrens

Balanced Floating Output Stage Circuit -  A great output topology based on a design by George D Pontis __  Contact:  info @ forsselltech . com

Battery powered Amplifier has optical isolation -  6-Jun-96 EDN Design Ideas:  When you interconnect scientific instruments, especially older ones, you often need both gain and galvanic isolation for the analog interface functions __ Circuit Design by W Stephen Woodward, Venable Hall, University of North Carolina, Chapel Hill, NC

Circuit Compensates Optocoupler Temperature Coefficient -  11/22/01 EDN Design Ideas:  When using an optocoupler in a linear application, you should consider its gain drift with temperature.  Traditional single- and dual-transistor-output devices have a notable gain drift with temperature.  In recent years, some temperature-compensated optocouplers have appeared.  However, another option is to use two optocouplers or a dual optocoupler with appropriate feedback to make the dri __ Circuit Design by J Michael Zias, Acme Electric Corp, Cuba, NY

Circuit Protects Computer's Input -  05/26/94 EDN Design Ideas:  The circuit in Fig 1 performs input protection, level translation, isolation, and debouncing.  The circuit allowed the output of a relay driver to connect to a computer even though the relay driver delivered a voltage as high as 24V and the relay driver had no ground connection.  With the values in Fig 1 the low and high thresholds at the circuit's __ Circuit Design by Ang Tzu Seng, Halliburton Drilling Systems, Singapore

Circuit Provides Universal Ac-Input-Voltage Adapter -  08/25/11  EDN Design Ideas:  Use a TRIAC and optocoupler to automatically change between doubler and bridge configurations.  he input-rectifier stage of an offline power supply converts an ac-line voltage to a dc voltage, which powers a dc/dc converter.  If you configure the rectifier section as a full-wave bridge for a universal mains input of 92 to 276V rms and 47 to 63 Hz, you must design the dc/dc converter to operate over a wide range of input voltages.  This approach increases the cost of components and reduces the efficiency of the dc/dc converter.   __ Circuit Design by JB Castro-Miguens, Cesinel, Madrid, Spain, and C Castro-Miguens, University of Vigo, Vigo, Spain

Circuit rejects Ambient light -  06/10/99 EDN Design Ideas:  In some applications, you need to detect light signals in the presence of background light whose intensity can change by orders of magnitude.  The circuit in Figure 1 uses an integrated photodiode/amplifier (OPT201) in conjunction with an integrator that drives two linear optocouplers (TIL300).    __ Circuit Design by Massimo Gottardi, IRST, Trento, Italy

Circuit Widens Optocoupler’s Response -  12/21/95 EDN Design Ideas:  Isolation amplifiers provide insulation for low-frequency analog signals at a high cost.  Optocouplers cost less and are widely used with digital signals.  However, you have to factor in limitations from distortion and bandwidth restrictions when using optocouplers.  The bandwidth limits result from a declining current-transfer ratio as a function of frequency.  You can use feedback techniques to improve the linearity, but the circuits are usually complex.  The circuit in Figure 1, which applies current drive to the optocoupler diode, improves bandwidth and allows easy frequency-response equalization. __ Circuit Design by Ferran Silva, Marcos Quílez, and Ramón Bragós, Universitat Politècnica de Catalunya  Barcelona, Spain

Compensate for Optocoupler Temperature Coefficient -  11/22/01  EDN Design Ideas:  When using an optocoupler in a linear application, you should consider its gain drift with temperature.  Traditional single- and dual-transistor-output devices have a notable gain drift with temperature.  In recent years, some temper __ Circuit Design by J Michael Zias, Acme Electric Corp, Cuba, NY

Cross-coupled gates prevent push-pull-driver overlap -  05/15/08  EDN Design Ideas:  Cross-coupled gates in the push-pull drive of a center-tapped transformer's primary prevent overlap __ Circuit Design by Richard Rice, Oconomowoc, WI

Drive High-Voltage Varactor Diodes From just 5V -  03/27/97 EDN Design Ideas:   How to connect two International Rectifier (El Segundo, CA]PVI1050s photovoltaic-isolator ICs in series to provide a20-Volt tuning drive for the varactor diode.    __ Circuit Design by Steve Hageman, Hewlett-Packard Co, Santa Rosa, CA

Dual Amp for Use with Opto Compressor Project -  PCB. ZIP containing schematic and gerber files.  __ 

Dual JFET-992/993 PCB -  containing schematic and gerber files.  For Use with Opto Compressor Project __  Contact:  info @ forsselltech . com

Fast analog isolation with linear optocouplers -  EDN Design Ideas:  06/12/2014    Implement isolated analog signals and current loops with linear optocouplers __ Circuit Design by Avago Tech Note

Generate 0.5v Negative Supply -  A while back someone needed a simple way to generate a negative 0.5v supply from a conventional transformer type AC to DC power supply.  The circuit below uses a couple schottky diodes and a filter capacitor to perform the feat . . . Hobby Circuit designed by David Johnson P.E.-July, 2011

Improved Optocouplers Reduce Current Draw, Resist LED Aging -  14-Dec-07 EDN Design Ideas:  With improved optocoupler circuits, you can enhance the accuracy of zero-voltage sensing __ Circuit Design by Peter Demchenko, Vilnius, Lithuania

Light powers isolation Amplifier -  01/21/99 EDN Design Ideas:  Self-powered isolation amplifiers, which need no external isolated power supply, provide versatile and convenient interfaces in many applications that require galvanic isolation of the signal source.  Examples of such applications include circuits that serve in industrial or medical environments, in which isolation Page includes several designs.  Scroll to find this one __ Circuit Design by Stephen Woodward, University of North Carolina, Chapel Hill, NC

Measure Optocoupler's Response Time -  09/08/11  EDN Design Ideas:  Measure the response speed of optocouplers in order to select matching devices.  You can use the circuit in this Design Idea to measure the attack and release times of photoresistor-type optocouplers (Figure 1).  Such devices often find use in audio compressors or volume-control circuits.  The design uses an oscillating Schmitt trigger with the optocoupler DUT (device under test) in the feedback loop.  The photoresistor and resistor R1 form a voltage divider that controls the input of the Schmitt trigger.   __ Circuit Design by Peter Demchenko, Vilnius, Lithuania

NEC Single & Multi-Channel Optocouplers 3/20/03 -  App Note  Doc #956__ California Eastern Laboratories

Negative 0.5 Volt Supply -  This simple circuit consists of two LEDs and a photo diode.  It generates a negative voltage with a current level of a couple milliamps.  It is ideal for supplying a negative rail to low power “rail to rail” op amp circuits, which need to have a true zero volts output.  Note:  This circuit is not particularly efficient . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006

Novel isolates temperature sensor from its host -  08/03/06  EDN Design Ideas:  Temperature-to-period converter and transformer driver provide power and signal isolation __ Circuit Design by Alfredo H Saab and Tamer Mogannam, Maxim Integrated Products Inc, Sunnyvale, CA


Opto Isolators:    #'s - N      M - Z

 


Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches



 About Us   |  Advertise on DiscoverCircuits.com   |   Report Broken Links  |    Link to DiscoverCircuits.com  |   
Privacy Policy


Discovercircuits.com endeavors to credit original designers.   Please alert us by eMail so we can
delete links to material that have been copied without your permission
.   Thank you.


© Copyright of all original material on this website is the property
of David A. Johnson, P.E. (Dave Johnson & Associates ) unless otherwise noted.  

Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.
All material is provided "as is" without guarantees or warranty of any kind, either expressed or implied.