Monday, June 30, 2008

What is the difference between a modular supply and a rack supply?

Modular supplies and rack supplies are the two generic categories into which Spellman's standard products typically fall. These product categories were created and used to help classify hardware. Additionally, Spellman provides a variety of custom and OEM supplies that would not adequately fit into either category.

Typically, rack mounted supplies are higher in power than their modular counterparts; but this is a generalization, not a rule. Rack mounted units usually operate off-line, requiring AC input. Rack mounted units usually provide full feature front panels, allowing quick and easy operator use. Spellman's rack mounted supplies comply with the EIA RS-310C rack-mounted standards.

Modular supplies tend to be lower power units (tens to hundreds of watts) housed in a simple sheet metal enclosure. Modular units that can operate off AC or DC inputs, can be provided. OEM manufacturers frequently specify modular supplies, knowing the elaborate local controls and monitors are usually not included, thus providing a cost savings. Customer provided signals, done via the remote interface connector, usually accomplishes operation, programming and control of these units.

When ease of use and flexibility is required, like in a laboratory environment, rack mounted supplies are usually preferred. Modular supplies tend to be specified by OEM users, where a single specific usage needs to be addressed in the most compact and cost effective manner possible. These are guidelines, not rules.

Thursday, June 26, 2008

High Voltage Power Supply Mission

The mission of this blog is to, from time to time, update this space with real world information as it relates to the daily and common use of high voltage power supply and supplies in our daily lives. For example, they are used in airport security scanners, xray machines, food and produce scanning devices and even the Genome Project!

When dealing with high voltage power and high voltage power supplies, it is most important that safety be given supreme and detailed attention. With this in mind, the first post will be on safety as it relates to high voltage power and will reference written material supplied by Spellman High Voltage Electronics Corporation:

What is a safe level of high voltage?
Safety is absolutely paramount in every aspect of Spellman's high voltage endeavors. To provide the maximum margin of safety to Spellman's employees and customers alike, we take the stand that there is no "safe" level of high voltage. Using this guideline, we treat every situation that may have any possible high voltage potential associated with it as a hazardous, life threatening condition. We strongly recommend the use of interlocked high voltage Faraday Cages or enclosures, the interlocking of all high voltage access panels, the use of ground sticks to discharge any source of high voltage, the use of external interlock circuitry, and the prudent avoidance of any point that could have the slightest chance of being energized to a high voltage potential. The rigorous enforcement of comprehensive and consistent safety practices is the best method of ensuring user safety.