Constant Current Electronic Electronic Circuits

Constant Current Circuits
Last Updated on: Saturday, June 27, 2009 04:42 PM

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

AN-D16: LND1 Series: Constant Current Sources And: Supertex Semiconductors (app note added 2/06)

AN-D18: DN25 Series: Constant Current Sources And: Supertex Semiconductors (app note added 2/06)

Bipolar current source maintains high output impedance at high frequencies: 12/5/05 EDN Design Ideas / (added 10/06) Use line-receiver/amp ICs to build high-frequency constant-current sources.

Build a Precise DC Floating Current Source: 08/18/05 EDN Design Ideas / (added 11/05) Use a general impedance converter and resistors to develop a specialized current source.

Circuit Forms Constant Current SCR: 02/01/01 EDN-Design Ideas / (added 11/05)

Circuit Forms Novel Floating Current Source: 05/01/03 EDN Design Ideas / (added 1/05) Figure 1 shows a polarization circuit applicable to ISFET (ion-sensitive field-effect-transistor) sensors. ISFETs are solid-state chemical sensors that measure the pH value of a solution in biomedical and environmental applications, for example. The circuit in Figure 1 is extremely simple; it sets fixed-bias conditions for ISFET sensors (VDS=I0 RX; IDS=I0)....

Circuit Provides Constant Current for Isfets/Memfets: 10/26/00 EDN-Design Ideas / (added 05/02) /

Constant Current Amplifier : (diagram added 6/03)

Constant Current Battery Charger: (circuit added 7/02)

Constant Current Constant Voltage Converter Drives White LEDs: 09/02/04 EDN Design Ideas / (added 1/05) LEDs usually take their drive from a constant dc-current source to maintain constant luminescence. Most dc/dc converters, however, deliver a constant voltage by comparing a feedback voltage to an internal reference via an internal error amplifier. The easiest way to turn a simple dc/dc converter into a constant-current source is to use a sense resistor to convert the output current to a voltage......

DN25 Series: Constant Current Sources: Supertex Semiconductors (app note added 2/06)

High Voltage Linear Regulator and Constant Current: Supertex Semiconductors (app note added 6/06)

LND1 Series: Constant Current Sources: Supertex Semiconductors (app note added 2/06)

LT1511 Low Dropout Constant-Current/Constant-Voltage 3a Battery Charger: DN144 Design Notes (Linear Technology) (app note added 6/06)

Op amp can source or sink current: 3/2/2006 EDN Design Ideas / (added 02/07) Bipolar current source beats familiar Howland-current pump.

Shunt Constant Current Source: Designed by Andrew R. Morris (electronic circuit added 9/05)

Signal Sources Conditioners and Power Circuitry: AN98 Linear Technology Eighteen circuits are presented in this compilation. Signal sources include a voltage controlled current source, an amplitude/frequency stabilized sine wave oscillator, a versatile, 0V to 50V wideband level shift and four sub-nanosecond pulse generators with risetimes as low as 20ps. Five signal conditioners appear; a unique, .... (added 9/06)

Simple 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 (0.1 ohm) 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..... (added 4/05)

TSM108 EVALUATING BOARD 12V to 6V DC/DC CONVERTER: The TSM108 is a step down controller that features constant voltage and constant current regulation. The Evaluation Board was designed to allow different converter configurations. Several options for power semiconductor footprints are available on the PCB in order to make it adaptable to a wide range of converter output power. In a first step, this App Note will describe the typical application. Then the various options available on the Evaluation Board PCB will be explained. (app note added 3/05)

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 (0.1 ohm) 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..... (added 4/05)