Many of you may be garden enthusiasts and would welcome the idea of automating some of the maintenance requirements of your plants. For example, keeping tabs on the quantity of water that is required by the plants based on the moisture in the soil, the available sunlight and the environmental temperature might be easy for an experienced gardener. However, gardeners who have just started gardening find it a difficult equation to balance. Even an experienced gardener may have to depend on a novice Read more [...]
An approaching thunderstorm creates a very stuffy environment with oppressively heavy moisture in the air. The presence of water in the air is termed as humidity and this largely affects human comfort. The amount of water vapor influences many physical, chemical and biological processes. In industries, measuring and controlling humidity is critical since it can affect not only the health and safety of personnel, it can affect the business cost of the product as well.
Sleep apnea leads to repeated Read more [...]
Industries are increasingly opting for low-power wireless photoelectric sensors with extended range of signals that carry for miles. Such improvements have been made possible with the proliferation of low-power micro-controllers that have boosted the range of the sensors and enhanced their battery life.
In general, wireless sensors conserve and extend battery life by switching themselves off when they are not taking measurements. This allows the sensor to spend most of its time not consuming any Read more [...]
Most touchless rotary sensors use a magnetic position marker for sensing position. The position marker is attached to the rotating part of the application. It also uses a sensor to measure the angle of the marker. The touch-less rotary sensor uses a magnetism-based technique and does not require physical contact between the marker and sensor. Although other noncontact magnetism-based sensors overcome the limitations of potentiometric sensors that use resistance-based track-and-wiper techniques, they Read more [...]
Your calculator probably has a darkish colored panel just above the display. The panel is made up of solar cells that power up your calculator if there is enough light. You may also have seen some solar panels, which people use for charging up their cell phones. Earlier, these solar cells or photovoltaic cells were exclusively used to power the electrical systems of satellites. However, they are now commonly used in less exotic ways as well.
How do photovoltaic cells convert light to electricity? Read more [...]
You might have noticed, the Raspberry Pi (RBPi) does not have any inputs for reading analog signals, unlike the PIC, AVR or the Arduino micro-controllers. This is because the RBPi is a digital only computer. Since many sensors generate only analog signals, it would be nice to make the RBPi analog-friendly by giving it some analog inputs.
Letting RBPi acquire some analog inputs is easy if you use the MCP3008 chip from Microchip. Since the RBPi does not have a built-in Analog to Digital Converter Read more [...]
BJTs, FETs and MOSFETs are all active semiconductor devices, also known as transistors. BJT is the acronym for Bipolar Junction Transistor, FET stands for Field Effect Transistor and MOSFET is Metal Oxide Semiconductor Field Effect Transistor. All three have several subtypes, and unlike passive semiconductor devices such as diodes, active semiconductor devices allow a greater degree of control over their functioning.
Depending on their subtypes, operating frequency, current, voltage and power Read more [...]
An inductor or an induction coil is a tightly woven coil of wire. Now, you would not expect an ordinary piece of wire to show any special property on passage of current through it. A coil with several loops or turns however, exhibits a remarkable property when current passes through it. The current through the coil creates a magnetic field in the immediate space surrounding the coil. The field stores electrical energy during the passage of current and for a very short while, even if you cut off the Read more [...]
Industrial equipment may need to operate in a region of strong electromagnetic fields. There can be a sudden surge in the voltage applied to the equipment, which may be hazardous to the user and the gear. It is crucial that you incorporate a reliable isolation system to take of these issues.
Until very recently, the optocoupler was the only practical choice in providing safety isolation for manufacturers of medical and industrial isolated systems. The arrival of digital isolator has however, changed Read more [...]