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Simple Circuit LED Constant Current Source - Chip manufacturers are always coming up with ever more sophisticated constant current driver chips for LEDs. We have included this design for those of you who prefer a more cheap and cheerful solutionmust register on this site __ Designed by Published in Elecktor July/Augu, 2010
Simple Circuit 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
Simple Circuit 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
Simple Constant Current Source - This simple constant current source uses an LM317 regulator IC. N. B. The pin-outs of the IC are not a mistake, the output is taken from the adjustment pin. I found this circuit to charge all my NiCad batteries, and I use a Kambrook mechanical light-timer (or equiv.) for 110vac to time the charge __ Designed by John Nooyen
Switchmode Constant Current Source - Operating a stepper motor using a fixed (constant) voltage supply results in poor torque at high speeds. In fact, stepper motors tend to stall at fairly low speeds under such conditions. Several approaches can be used to overcome this problem, one of which is to use a constant current supply in place of the more __
Test 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. . . Circuit by David Johnson P.E.-April, 2001
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. The charge current is reduced as the battery heats up. __ 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. It is designed to operate in a range of currents from tens of milliamperes to several amps. It does not use any hard to find parts; for example: an LM10 can be used to make an even higher performance circuit, but this IC is not multi-sourced and is likely to be discontinued. __ 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
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