19 hours ago •
GPS is everywhere! You have probably used and benefitted from GPS. They are found in most of the smartphones, many new automobiles and now even in smart watches. It helps you to get where you want to go. These tiny devices can give your position and time simultaneously almost anywhere on the planet.
But what is GPS? In this guide we will give an insight of what is GPS, how it works and what are the applications of a GPS module.
What is GPS
GPS (Global Positioning System) is a satellite-based navigation system. It provides time and location-based information to a GPS receiver, located anywhere on or near the earth surface. GPS works in all weather conditions.
The satellite system consists of a constellation of 24 satellites in six Earth-centered orbital planes, each with four satellites, orbiting at 13,000 miles (20,000 km) above Earth and traveling at a speed of 8,700 mph (14,000 km/h).
While we only need three satellites to produce a location on earth’s surface, a fourth satellite is often used to validate the information from the other three.
The GPs modules have become small over the years. These modules have tiny processors and antenna that receive data sent by the satellites and compute your position and time.
Working of GPS
GPS works through a technique called trilateration. Trilateration is the process of determining your position based on the intersection of spheres. When a receiver receives a signal from one of the satellite, it calculates its distance from the satellite considering a 3-D sphere with the satellite located at the center of the sphere. Once the receiver does the same with 3 other GPS satellites, the receiver then proceeds to find the intersection point of the 3 spheres to calculate it’s location. Used to calculate location, velocity and elevation, trilateration collects signals from satellites to output location information.
The GPS module receives a timestamp from each of the visible satellites, along with data on where in the sky each one is located (among other pieces of data). From this information, the GPS receiver now knows the distance to each satellite in view. If the GPS receiver’s antenna can see at least 4 satellites, it can accurately calculate its position and time.
A single satellite broadcasts a microwave signal which is picked up by a GPS device and used to calculate the distance from the GPS device to the satellite. Since a GPS device only gives information about the distance from a satellite, a single satellite cannot provide much location information. Satellites do not give off information about angles, so the location of a GPS device could be anywhere on a sphere’s surface area.
When a satellite sends a signal, it creates a circle with a radius measured from the GPS device to the satellite.
When we add a second satellite, it creates a second circle, and the location is narrowed down to one of two points where the circles intersect.
With a third satellite, the device’s location can finally be determined, as the device is at the intersection of all three circles.
Applications of GPS
GPS is a powerful and dependable tool for businesses and organizations in many different industries. Surveyors, scientists, pilots, boat captains, first responders, and workers in mining and agriculture, are just some of the people who use GPS on a daily basis for work. They use GPS information for preparing accurate surveys and maps, taking precise time measurements, tracking position or location, and for navigation. GPS works at all times and in almost all weather conditions. There are main uses of GPS:
- Location - Determining a position.
- Navigation - Getting from one location to another.
- Tracking - Monitoring object or personal movement.
- Mapping - Creating maps of the world.
Parameters for Selecting the Right GPS Module
1. GPS Pulse Accuracy
This is the accuracy of 1Hz pulse received from...Read more »
2 days ago •
Have you ever wondered how high voltage is obtained in Hybrid Electric Vehicles and Lighting system? Also a there have been a lot of situations where we need a higher voltage than our power supplies can provide. We need 12 volts, but have only a 9 volt battery. Or maybe we have a 3.3V supply when our chip needs 5V. Enter Boost Convertors.
It is a simple converter which is used to convert the DC voltage from lower level to higher level. Boost converters is also called a step up converter due to its function. In this guide we will see what is a Boost Convertor, how it works and the applications of it.
A boost converter (step-up converter) is a DC-to-DC power converter that steps up voltage from its input (supply) to its output (load). It is a class of switched-mode power supply containing at least two semiconductors and at least one energy storage element: a capacitor, inductor, or the two in combination. To reduce voltage ripple, filters made of capacitors are normally added to such a converter's output and input.
Power for the boost converter can come from any suitable DC source, such as batteries, solar panels, rectifiers, and DC generators. A boost converter is a DC to DC converter with an output voltage greater than the source voltage. A boost converter is sometimes called a step-up converter since it "steps up" the source voltage.
Working of Boost Convertor
The main working principle of boost converter is that the inductor in the input circuit resists sudden variations in input current. When switch is OFF the inductor stores energy in the form of magnetic energy and discharges it when switch is closed. The capacitor in the output circuit is assumed large enough that the time constant of RC circuit in the output stage is high.
When the switch is closed, current flows through the inductor in the clockwise direction and the inductor stores some energy by generating a magnetic field. Polarity of the left side of the inductor is positive.
(b) When the switch is opened, current will be reduced as the impedance is higher. The magnetic field previously created will be destroyed to maintain the current towards the load. Thus the polarity will be reversed (meaning the left side of the inductor will become negative). As a result, two sources will be in series causing a higher voltage to charge the capacitor through the diode.
While the switch is opened, the capacitor in parallel with the load is charged to this combined voltage. When the switch is then closed and the right hand side is shorted out from the left hand side, the capacitor is therefore able to provide the voltage and energy to the load. During this time, the blocking diode prevents the capacitor from discharging through the switch. The switch must of course be opened again fast enough to prevent the capacitor from discharging too much.
- In the On-state, the switch is closed, resulting in an increase in the inductor current;
- In the Off-state, the switch is open and the only path offered to inductor current is through the flyback diode, the capacitor and the load. This results in transferring the energy accumulated during the On-state into the capacitor.
- The input current is the same as the inductor current as can be seen in figure 2. So it is not discontinuous as in the buck converter and the requirements on the input filter are relaxed compared to a buck converter.
When a boost converter operates in continuous mode, the current through the inductor never falls to zero. In the steady state, the DC voltage across the inductor must be zero so that after each cycle the inductor returns the same state, because voltage across the inductor is proportional to rate of change of current through it.
Applications of Boost Convertor
- They are used in regulated DC power supplies.
- They are used in regenerative braking of DC motors
- Low power boost converters are used...
2 days ago •
We have all come across situations where we need a change of voltage which is lower because the power supply is of a different voltage. Luckily for us it is possible to convert one DC voltage to another. Enter Buck Converters. These electronic modules can step down the voltage from its input to the output.
In this guide we will see what are Buck converters and how do these modules work.
A buck converter (step-down converter) is a DC-to-DC power converter which steps down voltage (while stepping up current) from its input (supply) to its output. It is a class of switched-mode power supply (SMPS) typically containing at least two and at least one energy storage element, a capacitor, inductor, or the two in combination. To reduce voltage ripple, filters made of capacitors are normally added to such a converter's output and input.
The basic operation of the buck converter has the current in an inductor controlled by two switches (usually a transistor and a diode). In the idealized converter, all the components are considered to be perfect. Specifically, the switch and the diode have zero voltage drop when on and zero current flow when off, and the inductor has zero series resistance.
Working of Buck Convertors
The conceptual model of the buck converter is best understood in terms of the relation between current and voltage of the inductor. Beginning with the switch open (off-state), the current in the circuit is zero. When the switch is first closed (on-state), the current will begin to increase, and the inductor will produce an opposing voltage across its terminals in response to the changing current. This voltage drop counteracts the voltage of the source and therefore reduces the net voltage across the load. Over time, the rate of change of current decreases, and the voltage across the inductor also then decreases, increasing the voltage at the load. During this time, the inductor stores energy in the form of a magnetic field.
If the switch is opened while the current is still changing, then there will always be a voltage drop across the inductor, so the net voltage at the load will always be less than the input voltage source. When the switch is opened again, the voltage source will be removed from the circuit, and the current will decrease. The decreasing current will produce a voltage drop across the inductor, and now the inductor becomes a Current Source. The stored energy in the inductor's magnetic field supports the current flow through the load.
This current, flowing while the input voltage source is disconnected, when concatenated with the current flowing during on-state, totals to current greater than the average input current. The "increase" in average current makes up for the reduction in voltage, and ideally preserves the power provided to the load. During the off-state, the inductor is discharging its stored energy into the rest of the circuit. If the switch is closed again before the inductor fully discharges, the voltage at the load will always be greater than zero.
Applications of Buck Convertors
- POL Convertors for Laptops and PCs - A Point-Of-Load Converter, or POL, is a non-isolated buck converter that’s capable of efficiently driving power to high current loads. Modern microprocessors run off very low voltage, typically 1.8V.
- Battery Chargers - typically, a charging port for a mobile device is a micro USB port. It accepts a regulated 5V. The charging circuits are on the inside of the mobile device, which is often a buck converter.
- Solar Chargers - A solar charger is often a buck converter with a microcontroller control. The microcontroller tells the buck converter to draw the maximum amount of power by varying the load current to charge the battery in the shortest time possible.
- Power Audio Amplifiers
The Step-Down convertors can be used in other applications like it can be used as...Read more »