Posts Tagged ‘wanted’
Everything You Ever Wanted To Know About DIN Rail Power Supplies But Were Afraid To Ask
Posted by Parkzone Corsair in Power Supply on July 20th, 2010
A DIN rail, also known as a âtop-hatâ rail, is a standardised, 35mm wide metal rail with a hat-shaped cross section. It is widely used for mounting circuit breakers and industrial control equipment inside equipment racks.
In addition to the 35mm size rail there are other, less widely used types, including the 15mm, 7.5mm and the G-type rail. All DIN rails should carry British Safety standard certification, as with any electrical goods.
DIN rails and mounting hardware are used on computer boards. DIN is an acronym for Deutsche Institute fuer Normung, a German standardization body and member of the International Standards Organization (ISO). DIN rails and mounting hardware are standard mounting equipment for a variety of electronic components, including terminal blocks to connect wiring. DIN rails and mounting hardware are internationally approved, industry standard hardware for a vast array of components made by computer manufacturers. DIN rail terminal blocks also offer grounding and disconnecting capability and provide self-locking clamps to ensure a tight connection.Â
DIN rails most common applications are in general industrial applications including factory automation, electro-mechanical industry, data communications, IT, power distribution boxes, control panels, building automation and household appliance control. Their versatility in being able to deliver a power supply to multiple applications means that DIN rails are one of the most commonly used delivery systems.Â
When used to mount circuit breakers, DIN rail mounting means that the circuit breaker is much more easily accessible than if it were mounted using more traditional methods.
DIN rail power supplies are power supplies that are mounted onto the rail to allow external units to be connected to a power source. The best quality DIN rail power supplies should have the following features:Â
Universal AC input Short circuit, over load, over voltage protections Cooling by free air convection Can be installed on DIN rail TS-35/7.5 or 15 NEC class 2 / LPS compliant Built in DC OK active signal LED indicator for power on No load power consumption <0.75W 100% full load burn-in test
·         Fixed output voltage
By incorporating all of these into a power supply unit, the power delivery is safe and assured. The low power consumption makes these units an energy-efficient method of power delivery, keeping running costs down.Â
Larger units are available for three-phase power supply requirements, although these are mainly used in commercial applications rather than domestic ones. The inclusion of a UPS system will ensure that the power supply is uninterrupted, even in the event of a general power cut.Â
Modern DIN rail power supplies are compact, lightweight and reasonably priced. If you have a number of electrical appliances that require a continuous power supply, installing a DIN rail system saves space and improves efficiency by keeping your power supplies wall-mounted and away from deskspace. Including a circuit breaker in the design maximises safety and means that common faults can be dealt with quickly and easily. DIN rails should be installed by a professional electrician, who will be able to advise you on the best form of DIN rail power supply system to mount onto your rail.
Dean Curtis shared his expert knowledge on Din Rail Power Supplies. Check the information stored here for more details on modern Din Rail Power Supplies.
Everything you ever wanted to know about medical power supplies but were afraid to ask
Posted by Parkzone Corsair in Power Supply on July 17th, 2010
Medical power supplies differ greatly from average, domestic power supply units. Because of their application there are critical demands on medical power supply units for safety and reliability. Consequently, the units go through lengthy product testing before being certificated as being safe to use in a medical environment.
The amount of research and development involved in the manufacture and production of medical power supplies means that only a few producers actually tackle the field. One other aspect that tends to thin the herd is the possibility of product liability in the event of a power supply failure leading to a medical emergency or even, in a worst case scenario, a patient death.
Despite these concerns, a handful of power supply specialists are using their product development to provide units that can have medical applications. Their enthusiasm may be prompted by a small but steadily growing marketplace, as power supply units are required for more home-based medical equipment. A report issued by Frost & Sullivan in 2006 estimated that the world power supply market for medical applications would grow from $350million in 2005 to a projected $438.1million in 2012. This is just a fraction of the overall potential power supply market, and as new developments in medical treatments mean more patients can benefit from home care equipment, that forecast may be a little on the low side.
The rise of applications such as CAT scans, MRI devices, blood analysers and patient-monitoring systems for home care are also expanding the uses that medical power supplies can be incorporated into. In addition there are now specific requirements within hospital and medical centre applications that require power supply units that can give high power, reliable and efficient power delivery which are both cost effective and compliant with all legislation.
One of the concerns regarding compliance is that in some instances, end users are unaware that ordinary, commercial power supplies do not necessarily meet the required standard for application in medical equipment. Issues such as component spacing, insulation and leakage current can all cause a power supply to perform below standard, and in a medical situation where the life of a patient may depend on the power supply’s ability to cope with the application, this could prove fatal. The International Electronics Manufacturing Initiative (iEMI) addressed this in 2006 with a project that set out to develop reliability specifications for medical-grade electronic components, including medical power supplies. The ongoing project has so far achieved three objectives:
• Established draft protocol for acceptance testing based on a comprehensive Failure Mode Effects Analysis of failed devices. This protocol is currently being validated using components provided by different suppliers.
• Developed new optical inspection methods to screen components for macroscopic failures during testing. This automated system enables acquisition of large data sets quickly.
• Tracked reliability of parylene coatings (of neural recording electrodes) as a function of local chemistry and identified conditions of use that resulted in significant localized degradation at the probe tip.
It is essential for those who are looking to purchase medical power supplies that they ensure that the product they buy is fully compliant with all legislation that deals with medical equipment. It is critical that lives are not put at risk because of the desire to cut costs by employing unsuitable commercial power supply units that may not be able to cope with the demands put upon them by medical equipment. When choosing medical power supplies, the purchaser should always look for the highest quality product from a reputable supplier. They should also consider the end user – not the hospital, but the patient.
The above article on Medical Power Supplies was sent by Keith Finley. Read more about Medical power supplies here.
Everything you ever wanted to know about control panel power supplies but were afraid to ask
Posted by Parkzone Corsair in Power Supply on July 12th, 2010
Most modern high-speed, high-performance sensors and controllers require a reliable DC power source. Used in commercial applications, traditional, linear power supplies that relied on transformers to convert AC input into more manageable DC output are now being replaced by more compact and efficient switching power supplies.
Control panel power supplies are now taking this technology further, allowing businesses to operate using a DIN system that allows controllable power supply delivery to a range of applications.
Switching power supplies convert a DC voltage into a lower regulated voltage by storing the difference in a magnetic field. Because this removes the need for large coils within the system by incorporating smaller electronic methods of conversion, the size of the control panel power supply is reduced and more energy efficient. Switching power supplies are typically over 80% efficient, compared to 50% efficiency from linear power supplies. They are also light enough to be mounted on a DIN rail, which only the smallest linear supplies are capable of doing.
With modern development in power supply technology, switching power supply units often incorporate more advanced features as standard. Power factor correction (PFC) limits the harmonic current on the input side of the power supply, ‘cleaning’ up the input current which reduces the peak current demand. Overload protection protects the power supply from any damage caused by an abnormal rise in output current, and in turn protects any equipment that may be feeding off the power supply.
Overvoltage protection (OVP) prevents load circuit damage by cutting the power supply output when output voltage rises above 120% of the rated value. If the power supply feedback loop fails, for example, the output voltages could rise to levels that may cause major damage to the entire system. OVP detects this high voltage, shorts the output and causes the supply to shut down, preventing a surge that could be catastrophic.
Undervoltage detection indicates if the output voltage drops below a certain level.
When you’re planning to replace your control panel power supplies, there are a few things you need to consider. Firstly, what applications is the power supply intended for? You will need to know your input voltage and frequency, the output voltage, the wattage or power in amperes and the peak loading of the output. You will then need to calculate the power of the DC power supply you need. If more than one output is required, you will need to carry out a quick calculation to determine the total wattage for the supply by multiplying the voltage by the amperage of each output to calculate the individual wattage and then adding these together to give you your total wattage requirement.
You will also need to check the enclosure style, connections and physical size of the control panel power supply to make sure that it is suitable. A unit that is too large may not be suitable for some DIN rail fittings whereas a compact unit may not have the capability to cope with the number of outputs needed.
Although buying a second-hand unit on a web auction site may seem like a good way to save a few pounds, your control panel power supplies must conform to all safety legislation. Buying from a reputable dealer who offers a selection of approved and certificated units is the only safe and proper option when it comes to buying control panel power supplies.
Finally, consider the application that you wish to apply the control panel power supply to. This can include the power supply life, custom power ratings or mixed voltages. A good power supply will need to be able to cope with every requirement you have without having to work at maximum capacity for prolonged periods of time, which can shorten its lifespan. Talking to a technical expert who has experience in fitting control panel power supplies into commercial environments will give you more information and help you make an informed choice when it comes to selecting your power supply requirements.
Keith Finley sent the article on control panel power supplies . Know more about Control Panel power supplies here.
