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

DiscoverCircuits.com, has 45,000+ electronic circuits, cross-referenced
into 500+ categories.    We have searched the web to help you find quick design ideas.
We make every effort to link to original material posted by the designer. 
Please let us if you would like us to link to or post your design.

HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches



Current Source / Current Sink Circuits

Current Source Circuits:  #'s - B       C - G       H - S      T - Z
 

Last Updated: November 30, 2017 07:38 AM

Circuits Designed by Dave Johnson, P.E.

Tests UL Ground ResistanceUL requires that an electrical system using a metal chassis earth ground connection have a resistance of less than 0.1ohms.  This resistance must be tested with actual line current in excess or 10 amps.  The circuit shown uses a couple of LEDs to indicate if in fact the resistance is less than 0.1ohmsmodified on july 10, 2006 . . . Hobby Circuit designed by Dave Johnson P.E.-April, 2001

UL Ground Resistance TesterUL requires that an electrical system using a metal chassis earth ground connection have a resistance of less than 0.1ohms.   This resistance must be tested with actual line current in excess or 10 amps.    The circuit shown uses a couple of LEDs to indicate. . . Circuit by David Johnson P.E.-April, 2001




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

Tests UL Ground Resistance -  UL requires that an electrical system using a metal chassis earth ground connection have a resistance of less than 0.1ohms.  This resistance must be tested with actual line current in excess or 10 amps.  The circuit shown uses a couple of LEDs to indicate if in fact the resistance is less than 0.1ohmsmodified on july 10, 2006 . . . Hobby Circuit designed by Dave Johnson P.E.-April, 2001

Thermally Controlled NiCad Charger -  A voltage controlled current (maximum of 1A) is used to charge a NiCd battery.  The control voltage is derived from the temperature difference between the battery and the ambient air.   __ Linear Technology/Analog Devices App Note, Jun 21, 2011

Three-transistor current source covers wide range -  05/31/14  EDN-Design Ideas This Design Idea is a two-wire current regulator that strikes a good balance between performance and parts count.  Employing three transistors, three resistors, and one LED, it achieves good regulation   (better than 1% over most of the voltage range), lower operating voltage   (1.2V typical), and better tempco   (0.07%/K) than other circuits of similar complexity.   __ Circuit Design by Einar Abell0

Two Terminal 1A Current Source -  The LT3080 linear regulator can easily be configured as a two terminal current source __ Linear Technology/Analog Devices App Note, Mar 24th 2010

Two Terminal 3A Current Source -  The LT3083 is a 3A low dropout linear regulator that can be paralleled to increase output current or spread heat on surface mounted boards.  Architected as a precision current source and voltage follower, this new regulator finds use in many applications requiring high current, adjustability to zero, and no heat sink.  The device __ Linear Technology/Analog Devices App Note, Mar 9th 2011

Two Terminal 500mA Current Source -  The LT3085 linear regulator can easily be configured as a two terminal current source __ Linear Technology/Analog Devices App Note, Mar 24th 2010

Two Terminal Current Regulator (LT1635) -  The LT1635 combines an op amp with a 200mV reference.  Scaling this reference voltage to a potential across resistor R3 forces a controlled amount of current to flow from the +terminal to the –terminal.  Power is taken from the loop.  __ Linear Technology/Analog Devices App Note, Mar 31, 2010

Two Terminal Current Source -  The opamp buffers the upper potential of a shunt regulator to set a voltage drop on R1 equal to the reference.  The net current to RL is the programmed R1 current plus the quiescent supply current of the opamp passing through the reference.  __ Linear Technology/Analog Devices App Note, Jun 21, 2011

UL Ground Resistance Tester -  UL requires that an electrical system using a metal chassis earth ground connection have a resistance of less than 0.1ohms.   This resistance must be tested with actual line current in excess or 10 amps.    The circuit shown uses a couple of LEDs to indicate. . . Circuit by David Johnson P.E.-April, 2001

Variable Digital LoA - D -  This can also be used as a constant current source. __ Contact: Jameco Electronics

Variable Voltage Source -  The high current regulator below uses an additional winding or a separate transformer to supply power for the LM317 regulator so that the pass transistors can operate closer to saturation and improve efficiency.  For good efficiency the voltage at the collectors of the two parallel 2N3055 pass transistors should be close to the output voltage.  The LM317 requires a couple extra volts on the input side, plus the emitter/base drop of the 3055s, plus whatever is lost across the (0.1ohm) equalizing resistors (1volt at 10 amps) , so a separate transformer and rectifier/filter circuit is used that is a few volts higher than the output voltage __ Designed by Bill Bowden

Voltage Controlled Current Source -  Adding a current sense amplifier in the feedback loop of an adjustable low dropout voltage regulator creates a simple voltage controlled current source.  The range of output current sourced by the circuit is set only by the current capability of the voltage regulator.  The current sense amplifier senses the output current and __ Linear Technology/Analog Devices App Note, Mar 31, 2010

Voltage Controlled Current Source with Ground Referred Input & Output -  A flying capacitor device such as the LTC1043 can produce a precision voltage differential over a wide common mode range.  Here it converts a ground referred input voltage directly to a differential voltage across a fixed resistor which then forces a precise current sourced at the circuit output.  __ Linear Technology/Analog Devices App Note, Jun 21, 2011

Voltage-To-Current Converter Makes a Flexible Current Reference -  18-Sep-03 EDN-Design Ideas The voltage-to-current converter in Figure 1 can both source and sink current.  The circuit isflexible than some traditional current references that require different topologies for current sourcing and sinking.  Also, you can easily adjust the value of the current reference by simply adjusting the circuit's input voltage__ Circuit Design by Art Kay, Texas Instruments, Tucson, AZ

Voltage-to-Current converter offers precisely Defined Dead-band -  07/29/13  EDN-Design Ideas Dead-bands have application in control loops and other areas.  In the control of nonlinear and linear systems, sometimes a slight nonlinearity is intentionally inserted into the closed control loop.  “Slight” here means that the output of the inserted element starts to vary linearly, but only once the input exceeds a nonzero threshold value.  For inputs from zero to the threshold, the output of the element has zero value.  The result is that adding of this nonlinear element can quench damped oscillations, which are typical for feedback systems.  __ Circuit Design by Marian Stofka

Zener oscillators -  These two circuits are interesting from an academic point of view.  Their practical implementation is rather critical and it is not easy to get steady operation.  Circuit (a) requires a "cooked" zener: connect it first to a constant current generator, then increase the current __


Current Source Circuits:  #'s - B       C - G       H - S      T - Z


HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
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


Copyright  January, 1998 - November, 2017     David A. Johnson & Associates.  All Rights reserved. 


 Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.