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
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