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Form Constant-Current SCR - 02/01/01 EDN-Design Ideas A typical SCR (silicon-controlled rectifier) requires a trigger current, which causes the SCR structure to latch on. Once the device latches, the current through the SCR is solely a function of external component values. The SCR has no inherent ability to limit the current flow once it latches on. Current continues to flow, as long as the current exceeds a minimal value known as the holding current. The circuit in Figure 1 is similar to an SCR, because it also requires a trigger current to latch into its on state. __ Circuit Design by Robert Buono, Ringwood, NJ
Ground Referred Precision Current Sources - The zero drift LTC2054 instrumentation amplifier can be used in conjunction with one of Linear Technology's precision, low temperature drift shunt voltage references (in this example the LT1634) to create a precision, ground referred current source. __ Linear Technology/Analog Devices App Note, Mar 30th 2010
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 indicat . . . Hobby Circuit designed by Dave Johnson P.E.-April, 2001
High Accuracy 10mA Current Source - An external reference improves the initial accuracy and temperature drift of the LT3092 current source. __ Linear Technology/Analog Devices App Note, Mar 24th 2010
High Voltage 100mA Current Source - An external zener diodes protects the LT3092 and allows the part to be used in high voltage applications. __ Linear Technology/Analog Devices App Note, Mar 24th 2010
IC Current Sources-LT3092 - Current sources have been a well known but theoretical circuit component. Unlike voltage sources, a 0.01% accurate 2-terminal current source has been an elusive component that is not easily available and difficult to design. With the introduction of the LT3092, the current source as a drop-in component becomes a reality. The __ Linear Technology/Analog Devices App Note, Robert Dobkin-Vice President-Engineering and Chief Technical Officer Sep 15th 2009
LED Driver using Constant Current - LEDs are current driven devices. The light they produce is proportional to the current flowing though them. One way to maintain a fairly steady light output is to keep the current through the LED fixed, even as the supply voltage may change. A classic. . . Circuit by Dave Johnson P.E.-December, 2010
LT1511 Low Dropout Constant-Current/Constant-Voltage 3a Battery Charger - DN144 Design Notes___ Linear Technology/Analog Devices
NMH/NiCd 6v Battery Tester - I designed this circuit to test rechargeable six volt battery packs under constant current conditions. As designed, the circuit applies a 10 amp load to the battery pack. A heat sink must be used on the main power transistor . . . Hobby Circuit designed by David A. Johnson P.E.-December, 2004
Novel Floating Current Source - 05/01/03 EDN-Design Ideas One-shot provIdeas frequency discriminationFigure 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 i__ Circuit Design by
Casans, AE Navarro, and D Ramirez, University of Valencia, Burjassot, Spain
One Amp Current Injector - I designed and built this thing many years ago. I published the hobby circuit in the now defunct Radio Elecronics magazine back in 1992. The electronic circuit injects a precise 1 amp of current into any unknown resistor, up to about two ohms. Two alkaline . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2006
Op Amp can source or sink current - 03/02/06 EDN-Design Ideas Bipolar current source beats familiar Howland-current pump__ Circuit Design by Alfredo H Saab and Steve Logan, Maxim Integrated Products Inc, Sunnyvale, CA; Edited by Brad Thompson and Fran GranvilleMarch 2, 2006
Parallel Current Sources for Higher Current 300mA Output - The LT3092 can easily be paralleled for higher current outputs __ Linear Technology/Analog Devices App Note, Mar 24th 2010
Precision Current Source - A non-inverting amplifier configuration can force an input control voltage across a ground referred resistor. This creates a precise amount of current flow. This current must be sunk by the external transitors so the same amount of current flows from ground and sourced to a negative supply referred load circuit. __ Linear Technology/Analog Devices App Note, Jun 21, 2011
Precision Ground Referenced Voltage Controlled Current Source - The control voltage, Vin, is converted to a charge on a capacitor that is referenced to ground. This charge is transferred to place a differential voltage across the output current programming resistor. The output current then flows into a ground referenced load for a precision single supply circuit without the need for a voltage __ Linear Technology/Analog Devices App Note, Mar 16th 2010
Precision Nanoamp Bidirectional Current Source - This circuit sources and sinks just nanoamps of current with precision due to the low input bias current of the CMOS
op amps. A buffered difference amplifier and an integrator force the voltage across a 10Megaohm set resistor to be 1/1000 of the control input voltage in either polarity. __ Linear Technology/Analog Devices App Note, Mar 16th 2010
Precision programmable current source uses two ICs - EDN-Design Ideas 11/20/2015 Here are some programmable current source Design Ideaswhich make good use of precision on-chip component matching__ Circuit Design by Stefano Salvatori & Pietro Oliva
Precision Voltage Controlled Current Source - The ultra-precise LTC2053 instrumentation amplifier is configured to servo the voltage drop on sense resistor R to match the command VC. The LTC2053 output capability limits this basic configuration to low current applications. __ Linear Technology/Analog Devices App Note, Mar 31, 2010
Programmable Switching 1.5A Current Source - The LTC3600 is a high efficiency, monolithic synchronous buck regulator whose output is programmed with just one external resistor. The accurate internally generated 50μA current source on the ISET pin allows the use of a single external resistor to program an output voltage that ranges from 0V to 0.5V below VIN. The VOUT __ Linear Technology/Analog Devices App Note, Jan 16th 2012
Provide constant-current load for testing batteries - 02/19/09 EDN-Design Ideas A 9V battery provIdeas power for a constant-current source for testing AA- or AAA-size batteries__ Circuit Design by Vladimir Rentyuk, Modul-98 Ltd, Zaporozhye, Ukraine
Provides Efficient Fan-Speed Control - 03/04/04 EDN-Design Ideas As Moore's Law plunges us into the realm of multigigahertz processors and PCs with gigabytes of RAM, engineers face the task of removing the heat that these state-of-the-art components produce. Cooling such systems poses a dilemma. __ Circuit Design by John Guy, Maxim Integrated Products, Sunnyvale, CA
Provides Motor Feed Control - 07/25/02 EDN-Design Ideas Linear power driver works from single supplyBecause we needed a small grinding machine, we modified an old milling machine that lacked a control system. The table of the grinding machine needed only to move back and forth with__ Circuit Design by Jean-Bernard Guiot, DCS AG, Allschwil, Switzerland |
