We've included this handy glossary to help with the terminology & abbreviations relating to power products. Pick a letter below to begin, or download the glossary to refer to it whenever you like.A B C D E F G H I J K L M N O P Q R S T U V W X-Z #
An electrical connection to the earth frequently using a grid or rod(s). See also Ground.
The ac or dc current to chassis/earth of a power supply (PSU) at a specified input voltage/frequency. Medical power supplies have specific requirements for Earth Leakage currents and this varies depending on standard to be met.
The value of a waveform that has the equivalent effect of a direct current. The Effective Value = RMS (Root Mean Square) Value
(For sine waves this equates to √2 x Peak value).
The ratio of total output power to total input power, expressed as a percentage, under specified conditions. Maximum theoretically possible efficiency is 100%. A power supply which is 90% efficient wastes one third as much power as a power supply which is 75% efficient. As efficiencies approach 100%, improvements become harder to achieve.
Abbreviation for Electronic Industries Association.
Industry standard footprint for dc-dc converters. Dimensions are 57.9mm x 22.8mm (2.3in x 0.9in). See also Full Brick, Half Brick, Quarter Brick, Sixteenth Brick. Lambda's PAE range of dc/dc converters are examples of eighth bricks.
Property of matter that results from the presence or movement of electric charge.
A capacitor that contains two electrodes separated by an electrolyte.
A type of magnet in which the magnetic field is produced by a flow of electric current. The field disappears when the current stops.
The capability of equipment or systems to be used in their intended environment within designed efficiency levels without causing or receiving degradation due to unintentional EMI. EMC generally encompasses all of the electromagnetic disciplines.
Any electronic disturbance that does or could interrupt, obstruct, or otherwise impair the performance of electronic equipment. EMI is characterised by the following categories for test and measurement purposes: 1. Conducted Emissions, 2. Radiated Emissions, 3. Conducted Susceptibility, 4. Radiated Susceptibility.
Force that causes free electrons to move in a conductor. Unit of measurement is the volt.
Negatively charged particle.
A unit of energy. The energy acquired by an electron passing through a potential of one volt.
US based trade group http://www.eia.org/
Test equipment which draws controlled amounts of power or current from a power supply. Part of the ATE used to fully test a power supply during its functional testing stage.
The flow of current that results when objects having a static charge come into a close enough proximity to discharge. Usually used to describe momentary unwanted currents that cause damage to electronic equipment / components.
Electric field around a charged body.
A conductive screen that shunts induced energy to ground. See Faraday Shield.
Abbreviation for Electromagnetic Compatibility.
Abbreviation for Electromagnetic Interference.
A circuit for the attenuation of the electromagnetic interference emitted from (or received by) a power supply (PSU) or other equipment. See also EMI.
Abbreviation for Elektromagnetische Verträglichkeit (German: Electromagnetic Compatibility).
Abbreviation for Norme Européen (European Standard).
A signal input to a power supply which will turn on the outputs (if the unit is fan cooled then this may also enable the fan). The signal has to be activated to make the outputs turn on. With nothing connected to the input, the power supply should not operate. (Compare this with Inhibit).
See Rotary Encoders
The capacity of a system to do work. The unit is joule.
The amount of inductance in series with an ideal capacitor which exactly duplicates the performance of a real capacitor.
The amount of resistance in series with an ideal capacitor which exactly duplicates the performance of a real capacitor.
Abbreviation for Electrostatic Discharge.
Abbreviation for Equivalent Series Inductance.
Abbreviation for Equivalent Series Resistance.
A serial communication bus mostly used to connect equipment in a LAN (local area network). Some power supplies can be supplied with Ethernet communications to allow remote control via the computer network. See Communications Port.
standard adopted by CEN/CENELEC and carrying with it an obligation of implementation as an identical national standard and withdrawal of conflicting national standards.
SI prefix multiplier. Multiplies by 1018. So 100 EF = 100 x 1018 F. Written as 'exa'. Abbreviated to 'E'.
Criteria for externally fitted fuses in the input lines of a Lambda power supply.
Normally the internal fuse fitted in the power supply is rated approximately 20 - 25% greater than the maximum I/P current at low line and maximum load to overcome nuisance blowing.
The addition of external fusing is usually for one of the following reasons:
1. The supply is to be used in a medical application and therefore must have dual fusing.
2. To allow the customer to change fuses in the event of a problem because the unit fuse is NOT accessible. WARNING: If the fuse blows immediately after being replaced the Power Supply must be viewed as having a serious malfunction and must be returned to Lambda.
3. The Power Supply is to be connected to a non-polarised mains supply (where it is not certain which line is live).
It is important therefore, to consider the following when selecting fuses to be fitted externally to the Power Supply:
Any external fuse:
1. Should not be rated higher than the fuse fitted inside the power supply (the internal fuse rating is stated in the installation manual).
2. Should be a minimum of one rating below the fuse fitted in the Power Supply (see note 1)
3. Should have at least the same speed of response as the fuse fitted inside the power supply. e.g. FAST or SLOW acting.
4. Should have High Breaking Capacity.