Voltage Regulators: Explained.

Introduction:

    In the world of electronic circuit design, the selection of the right voltage regulator is one of the most important decisions. Virtually, every product that runs on DC power employs voltage regulation.

                                        

Voltage Regulators:

    As the name indicates, voltage regulators take a variable or unstable input voltages and convert them to higher or lower constant output. That matches the voltage and current needs of an electronic circuit. Basic regulators of the linear IC type regulators simply drop down the source to the desired level and shed the rest as heat while the others such as the switching type are more efficient. Simply stated, rapidly switching a voltage input on and off results in an averaged voltage output, depending upon switching frequency. A wide range of voltages is possible from a single source. Some regulators employ additional features to handle large voltage spikes, reverse polarity protection, or remove unwanted signal noise, automotive alternators.

For use in electrical systems and charging the vehicle's battery, most alternators employ a built-in AC to DC rectifier and a robust voltage regulator that is capable of delivering 13.5 to 14.5 volts DC above 100 amps. Each device in the electrical system may have its own voltage regulator depending on its specific needs. Common voltages are 12 volts DC for lighting and accessories and 5 volts DC for sensors and control modules. 

Types:

Linear regulators use a transistor that is controlled by feedback from a differential amplifier circuit and a reference voltage to control the output voltage. They may feature fixed or adjustable output. Output current is determined by the input current minus circuit operation losses. Linear regulators are simple to add and give a fast response time but are not very efficient. The output of a linear regulator is always lower than the input and drops out if the input voltage is too low. 

Switching regulators are very efficient but can be difficult to design. As mentioned, earlier switching regulators use controllers to rapidly connect and disconnect either the positive or negative component of the source voltage from the rest of the converter circuit to produce desirable changes in voltage and current. A feedback loop from the output to the controller helps to determine the switching rate. The arrangement of inductors, capacitors, and diodes in basic switching converters determines if the output voltage is increased or decreased.

Buck-boost converters can increase or decrease voltage but

reverse the polarity.

Fly-back transformers increase the voltage to 

very high levels but at very low current by collapsing the field of an energized coil much like the ignition system in some

automobiles.

These are the basic functionality, types, and common

applications of voltage regulators. 

Stay tuned. Bye.

Heat sinks: Explained.

Introduction: 

    Modern electronics pack an incredible amount of complexity into a very small space which creates a lot of heat. If left unchecked, it could reduce your device's lifespan or even destroy outright the processor that created it. That's why when you first open up a PC or other electronic device, one of the first things you'll see is one or more large metal objects called heat sinks. 

Heat Sinks:

    Inside a PC, heat sinks will be found on the CPU, graphics card, motherboard, inside the power supply, and even in other places as needed. As you can see, they can look very different from each other. But they all serve the same basic purpose to remove heat from delicate components and extend their lifetimes. 

Kinds:

    Let's walk through some of the different kinds of heat sinks you might encounter. 

First up is the heat spreader. This is the most basic heat sink and it consists of a simple flat piece of metal. It only moderately improves heat dissipation because metal will transfer heat to the surrounding air faster than plastic. It would be much more effective if it also increased the size of the area of the surface that's being used to transfer that heat.

The next common type is passively pinned or finned heat sinks. These basic heat spreaders with structures on top of them that dramatically increase the surface area that can be used to dissipate heat to the surrounding air. They are much more effective than heat spreaders but they are also more expensive to make and they take up more space.

Speaking of taking up space, adding a fan to blow air directly adds a thinned or pinned heat sink which is relatively inexpensive and very space-efficient as a means of dramatically improving heat sink performance. For this reason, actively cooled thinned heat sinks are one of the most common types of heat sinks found in PC systems where size and cost are major design factors.

Speaking of the cost of the most effective and the most expensive, the common type of heat sink in a PC is a heat pipe or vapor chamber heat sink for very hot components like CPUs or graphics cards. The limiting factor of a standard Thin heat sink's performance is no longer the speed at which the fins can be used to dissipate heat to the air. But rather the speed at which the heat can be moved away from the very small processor core to the fins in the first place. Heat pipes and vapor chambers usually consist of an outer copper wall and material inside that is constantly changing phases between liquid and gas. They can be used to carry heat away from a small heat source extremely quickly to a large array of heat sink fins where it can be dissipated to the air. 

How to improve your heat sink?

An important question is that what can you do to improve your heat sink performance. Number one is to lower the ambient temperature. If cracking open a window lowers the room temperature by five degrees, it will lower your heat sink temperature by about five degrees.

Number two is more airflow, the faster the air moves over the heat sink. The better it will perform. 

Number three is a better thermal interface material. No two pieces of metal will ever meet up perfectly and thermal interface materials fill in these micro gaps for better heat conduction or better heat transfer between them. Replacing the subpar solutions that come pre-installed on your components with high-performance aftermarket thermal compounds can easily lower temperatures by several degrees.

Number four is mounting a good solid mount which improves the contact between a chip and a heat sink and ensures effective thermal transfer. A heat sink that isn't performing as expected is often held back by an air bubble trapped in between or a small component. Nearby that is interfering with the heat sinks mounting pressure. 

That's all.

Stay tuned.

Bye.