Welcome to the Bulgin page on element14. Here you can find things such as our latest news, training videos, and product details. Additionally, you can engage with us in our forums.
If you have ever had to research switches or even select a switch for a piece of electronic equipment, the number of switch technologies available on the market today might be a little overwhelming. This blog post will focus on two switches that look very similar but function according to completely different electronic principles. The question is: just what is the difference between a piezo switch and a capacitive touch switch?
First, let us examine some of the aspects that the two have in common.
Both types of switches are usually comprised of flat, metallic discs, sometimes surrounded by an illuminated ring that lights up when the switch is activated.
Typically they are installed flush with the control panel, and with no moving parts they are often highly wear-resistant, dustproof, waterproof and suitable for repetitive operation. The durability of these switches means they can withstand millions of actuations and require little to no maintenance.
A piezo is a small disc comprised of two layers; an inner ceramic layer and an outer layer usually made from a metallic substance. It reacts to the force of being touched and generates an electric charge, which effectively sends a signal that the button has been pushed.
A piezo switch relies on mechanical displacement or bending of piezo ceramic – also known as the piezoelectric effect. The word piezo is derived from the Greek piezein, which means to squeeze or press. While there are no mechanical moving parts within the switch, it does require sufficient pressure to be applied in order to deflect the ceramic layer within.
On the other hand, a capacitive switch, also known as a capacitance switch, requires just one electrode, which can be placed behind a non-conductive panel. The switch uses body capacitance, making use of the electrical charge naturally carried by the human body. The difference between the device itself and the fingertip is sensed, thereby triggering the switch.
A piezo switch senses touch force or relies on a small force, while capacitive switches require a charge or electrode, typically generated from human touch. So for devices that are meant to react only to human touch, then the capacitive touch switch is ideal for this purpose.
Capacitive switches are used in a wide selection of applications, from medical and laboratory equipment and food processing machinery to consumer applications such as appliances, vending machines and lift controls.
Price wise, capacitive switches are typically cheaper than piezo switches from a raw materials perspective.
A user wearing thick gloves cannot operate a capacitive switch. They do however work with thin surgical gloves or specially designed conductive fibre gloves that will allow a charge to be passed from the hand to the switch. This is where the piezo switch truly comes into its own – these switches will function regardless of the type of glove the user is wearing as the switch depends on pressure to operate, not human touch.
Bulgin’s range of piezo switches are vandal-resistant, waterproof and dust proof with an ingress protection rating of IP68 and IP69K, and the company’s range of highly durable capacitive touch switches will also soon be released.
For more information about Bulgin's piezo switches please visit: www.bulgin.com
Despite being a relatively routine activity in the oil and gas sector, subsea exploration is not cheap to perform, costing up to a million dollars a day for vessels, ROVs and personnel. To avoid unplanned downtime – and the associated additional expenditure – it is essential that mission critical equipment is readily available and does not suffer connectivity issues. Christian Taylor discusses the challenges associated with developing new solutions for this market.
Remotely operated underwater vehicles (ROVs) are integral to the oil and gas industry’s subsea operations. In the region of 500 ROVs are in active field use at any one time – with a further 2,000 on standby globally – performing a range of exploratory and maintenance activities on the seabed at depths well beyond the capabilities of manned submersibles. As the name suggests, ROVs are not autonomous, but are linked to the host ship via a neutrally-buoyant tether to allow direct operator input at depths of up to 7,000 metres. Downtime to resolve communication issues is a major problem for the industry, with ROV hire alone costing up to $100,000 a day, plus the significantly higher costs of chartering and crewing the host vessel. Robust connectivity solutions that maintain an effective link between the operator and ROV are essential, ensuring unplanned and unnecessary downtime is avoided.
Subsea exploration – a connectivity challenge
ROVs are frequently required to operate in harsh conditions – rough seas, thick sediment and very deep water – and the design of connections between the ROV and its umbilical tether have traditionally depended on ‘heavy engineering’ solutions to ensure reliability. However, this approach has a significant drawback, as connectors designed to continuously withstand extreme pressures and corrosive environments for many years are often very difficult to access or terminate and de-terminate; termination of ROV tethers for deployment can routinely take up to 24 hours. The inefficiency of this process, coupled with its potential for costly delays, led the industry to investigate alternative connectivity strategies, turning to other automation markets for possible solutions to enable ROV tethers to be terminated and de-terminated in an hour or less.
Built to withstand extreme environments
The Bulgin name is synonymous with dust and waterproof connectivity solutions for a vast array of applications, and the company has extensive experience in developing innovative connectivity solutions for use across multiple engineering disciplines. However, even for a company with such wide-ranging expertise, the high value/low volume subsea applications market presents a truly unique set of challenges that require completely bespoke solutions, rather than off-the-shelf mass produced connectors.
Using its broad knowledge of environmental sealing and connector design, the Bulgin team has developed the ROV Tether Connector, a novel device that provides a quick yet secure mating solution. Its circular design, 316 stainless steel casing and threaded collar locking mechanism offer uninterrupted power, data and fibre optic connectivity. To enable operation at the high pressures associated with working at depths of 3,000 to 7,000 metres, the Tether Connector is a compensated unit, using free flow of dielectric oil from the ROV itself to provide dynamic pressure balancing.
‘Cross-talk’ between the high voltage power lines (up to 5 kV) and low voltage data lines is one of the biggest challenges to overcome with this type of multi-feed connector. Ideally, the screening path from the umbilical tether through the connector interface and into the ROV should be uninterrupted but, when the bulk of the individual connectors for each feed are taken into account, this is not practical. The problem is resolved by using a combination of carefully designed connector geometry and screening materials to isolate the various power, data and optical feeds. Anticipating that power and data demands are likely to vary with each generation of ROVs, the Bulgin team chose a modular internal construction, future proofing the Tether Connector and simplifying reconfiguration for new applications.
An exceptional solution for subsea applications
Bulgin’s combined connectivity expertise and bespoke engineering capabilities have enabled it to develop a truly unique solution for the subsea market; the ROV Tether Connector. This innovative solution provides complete environmental sealing and reliable operation to depths of 7,000 metres, and allows rapid and reliable tether coupling to be accomplished in as little as 30 minutes.
For more information about Bulgin products, please visit: www.bulgin.com
Optical fiber is everywhere in the world, from home broadband and telecommunications to the undersea cables that connect continents together. Billions of people across the world now rely on these networks of silica strands to make communication and access to information instantaneous, cost-effective and reliable. And since it is lighter, smaller and faster than copper wire and cheaper than satellite, optical fiber is the obvious choice to help usher in the new age of connectivity and big data.
Unlike copper wire, optical fiber rarely requires amplifiers. The light signal is transmitted down the central core, which is wrapped in a reflective layer to create what is known as total internal reflection. However, whether installing optical fiber networks to the home, to the antenna, to the server room or any other application, network engineers can face the challenge of various types of insertion loss, or weakening of the optical signal, which is measured in decibels.
For high quality single mode fiber, loss should be as low as 0.1 dB/km. However, it’s impossible not to incur some degradation of signal over the full length of the network connection. Here are some of the ways you can limit insertion loss when using fiber optic connectors:
Polish and clean the ends
A rough cut can result in a scattered signal and may also trap dirt particles around the edges. As the fiber is hair-thin, even airborne dust particles can scatter and absorb light signals. After cutting with a cleaving tool, polish the ends with a professional polishing kit and wipe with a lint-free isopropyl alcohol wipe, ensuring that your skin never touches the end of the ferrule.
Minimise end gaps
In an optical fiber connection, if there is any gap between the two fibers this can cause the emerging cone of light to be refracted by the air, thereby causing losses in the signal. Ensure that the fibers are not cleaved at an angle, and that the connecting fibers are lined up perfectly without any gaps.
Connect the same size fibers
As there are several different types of optical fiber available on the market, it is possible that you may need to connect two different types together in a network at some point. If you connect a small fiber to a larger one, the losses resulting from this will be minimal, but a large fiber should never be connected to a smaller one, as this will result in substantial losses due to the difference in core size and the numerical aperture of most small core fibers.
Avoid unnecessary bending
Bending of fiber optic cables is a major cause of insertion loss due to light refracting through the cladding. Optical fiber cables can quite easily become coiled or kinked during installation, and each small bend or coil can cost a loss of up to 0.2 dB. Minimise tight bends and if the cable must be coiled, keep the radius as large as possible.
Protect the connection
If your connection is going to be in any way exposed to dirt, water, salt spray high/low temperatures, or any type of shock, it’s essential to consider the best way to protect the safety of the optical fiber connection. This could be done with a purpose-built box to protect the connection, or with a high-quality rugged connector housing with a secure locking mechanism that will protect the interface from ingress. Bulgin’s 4000 Series Fiber range of rugged LC connectors are specially engineered to keep fiber connections protected from any kind of environment. Featuring a secure quick-twist bayonet connection, the 4000 Series is IP68 rated and offers an average insertion loss of <0.1 dB.
For more information about the 4000 Series Fiber range, please visit: www.bulgin.com
Optical fiber has become increasingly popular, providing high-speed, reliable data transfer and communications for a huge range of applications. As well as the fiber itself, it’s important to pick the right connectors for the job, but navigating through the multiple options that are available can be confusing.
In fact, there are three types of fiber connectors in common usage: SC, ST (bayonet-twist) and LC (push-pull locking). The most frequently specified is the LC connector, the most suitable for space-constrained applications as it is much more compact than the other two – not only that but because it provides a secure clip connection, there is much less of a chance of the fiber accidentally disconnecting.
Simplex or duplex?
Also up for consideration is another additional complication: fiber optic LC connectors are available in simplex and duplex options. What does that mean? Let’s break it down. A simplex optical fiber is only capable of transmitting data in one direction as it only uses a single strand of glass or plastic fiber. This means that this type of fiber is perfect for applications in which uni-directional capability is needed. For example, transmitting data from a sensor in an Internet of Things (IoT) system. Therefore, a duplex optical fiber can transmit data in both directions as it consists of two strands of fiber. A duplex optical fiber also has two variants. It might be ‘half duplex’ which only sends data in one direction at a time, or it may be ‘full duplex’ which handles simultaneous, bi-directional communications. More obvious than not, simplex fibers cost less than duplex fiber thanks to the use of one fiber and not two. It should also be noted that both simplex and duplex fibers are available as either single mode or multimode versions, depending on the needs of any particular use case.
(4000 Series Fiber simplex connector and 6000 Series Fiber duplex connector)
Connectors for harsh environments
Once the type of fiber that will be used has been chosen, the appropriate LC connecter that matches the fiber needs to be specified – simplex or duplex? For some applications, a standard LC connector will be suitable but as fiber use is on the increase, this means outdoor applications are on the increase too. The use of fiber in outdoor installations and harsh environments means that delicate optical fiber is at risk from moisture, dust and dirt which can in turn affect the transmission of light which then affects the data rates achieved. Although the fibers themselves are protected by an acrylic layer, the connectors can be vulnerable in outdoor usage. In the most extreme situations, water could gain access inside a connector and freeze. This can cause damage to the fiber which has the potential to cease and communication. Standard LC connectors, however, are not rugged enough for harsh environments which means that it cannot be guaranteed that water or moisture will not make its way into the connector. You could use a custom enclosure to protect the connector, but this can prove expensive and large in size. More often than not, too expensive and too big. A better answer is to specify a rugged LC connector, such as the 4000 series fiber range from Bulgin, which provides an industry-standard LC interface as specified by IEC 61754-20. This connector protects the ends of the optical fiber from dirt and damage, and provides a seal to prevent any ice forming. The fiber connection provided by the 4000 series is UV resistant, salt spray resistant and sealed to IP66, IP68 and IP69K. It also provides a secure quick twist bayonet connection, ensuring durable mechanical mating. The connector operates over a wide operational temperature range of -25 to 70ºC, with an average insertion loss of less than 0.1dB and a maximum insertion loss of 0.2dB.
Visit Bulgin’s Connectivity Community for expert advice on optical fiber connectors and installations in harsh environments.
