LM317T Voltage Regulator with Pass Transistor

An explanation of how the circuit works for the dummy load and some tweaks to increase the constant current. --------------------- Click "Show more" ------------------------------- My website and forum:- www.mjlorton.com Donations and contributions www.mjlorton.com My techie channel MJLorton - Solar Power and Electronic Measurement Equipment - http My Techie Amazon Store: astore.amazon.com My other channel VBlogMag - For almost any topic under the sun! - www.youtube.com My VBlogMag Amazon Store: astore.amazon.com ----------------------------------------------------------------------- Link to Kibi's "Dave Jones' dummy load with added features" : mjlorton.com Dave Jones / EEVblog video: www.youtube.com WHAT IS AN OP-AMP?: talkingelectronics.com My components: * Infineon MOSFET N-channel 200V 13.5A TO-220 - BUZ31L H * Vishay 534 Series Pot with 6.34mm shaft, 50K * 2 x 10 k Ohm resistors * Arcol HS50 Al house wirewound high power resistor,1R (1 ohm) 50W - HS50 1R J * National Semiconductor Quad op amp,LM324N 1MHz DIP14 * How does an N Channel logic level MOSFET work - gate voltage, variable resistance, heat dissipation. * How does a LM324N Op Amp work - voltage follower, comparator, rail to rail, head room, feedback loop.



http://www.youtube.com/watch?v=hgrvJ2b2xfg&hl=en

Link to page: www.pcbheaven.com This is the remake of the third episode of the LED driving and controlling methods Theory Series. In this episode i explain how can someone design a constant current LED driver with a single transistor, biased with a Zener diode to achieve constant current regulation regardless of the power supply voltage. Additionally, i analyze a second circuit with sme functionality but instead of the Zener diode i use two simple diodes. On-line calculator for this circuit: www.pcbheaven.com



http://www.youtube.com/watch?v=fMc99rM6u4k&hl=en

A basic introduction on constant voltage and constant current modes of the power supply. Second part : www.youtube.com



http://www.youtube.com/watch?v=AsBx52mWzwM&hl=en

www.onsemi.com Learn about alternate solutions for driving LEDs. Watch a demonstration of a T8 fluorescent tube light replacement comparing a common switching regulator based solution and a Constant Current Regulator (CCR) biased solution for driving LEDs. See the benefits of using CCR's for driving LED applications.



http://www.youtube.com/watch?v=IiPHkdgTgaU&hl=en

www.onsemi.com Learn about the different solutions available for driving LEDs in various applications. Watch a demonstration of a trailer light application comparing a common resistor biased solution and a Constant Current Regulator (CCR) biased solution. See the benefits of using CCRs for driving LED applications.



http://www.youtube.com/watch?v=zKVL2XWqDI0&hl=en

Using the LM317LZ 100ma adjustible voltage regulator and one resistor, you can make a constant current source. With the LM317 1.5 amp version, you can make one with higher currents. I made an error during the video: I said volts when I mean milliamps. (you probably figured that out though).



http://www.youtube.com/watch?v=2UDVLeCqZl0&hl=en

High copper prices have a great impact on power cable prices, especially for larger sized cables having long runs. Prices have sky-rocketed over the last few years and it is with this in mind that Ashley-Edison developed a product to "compensate" for the problem.

Many owners, developers and contractors have to suffer this expensive problem, but by incorporating a "Constant Voltage Compensator" an installation cost may be drastically reduced.

When the voltage across a cable drops to a low value, the "Compensator" is able to detect this and compensate by boosting the voltage to a preset value - of say 400V. Using an "output sensor" it will continuously monitor the output voltage, which is checked against a "comparator", and if there is any shortfall it will instruct the transformer to add (+) or "boost" the voltage to its required value by means of a servo motor. In this way, the output voltage is continuously monitored and maintained.

This system does not emit any harmonics and has been a well proven voltage stabiliser design, in use for many years.

The "Compensator" is very suitable for use on Golf Course Lighting/Equipment, Perimeter Lighting applications and Farm/Estate Buildings etc. where long cable runs are an issue.

Both Indoor and Outdoor enclosure types are available to suit a variety of needs.

Alternative "Booster Transformers" have a main disadvantage as their output voltage is "following". This means that whatever the input voltage, the "transformed step-up" output voltage will not remain constant - fluctuating according to any load changes which will transmit to the load where it may be too high or too low. The voltage from no-load to full-load will cause the voltage drop to change drastically, which will not help improve the voltage drop. The "less than 4% volt drop window" is still not fulfilled and it is required to use a larger than necessary cable size. In fact, this does not help resolve the problem of expensive cables!