flashboard

• (board placed upon a milldam): flushboard

flashboard (plural flashboards)

1. (US) A board placed temporarily upon a dam, river, stream, etc. (typically within a permanent frame) to raise the water above its usual level.
   • 1909, Herbert Michael Wilson, Irrigation Engineering, page 168:

     A form of cheap open weir which has been commonly constructed in the West is the open wooden frame and flashboard weir.

   • 1952, Tennessee Valley Authority, Design of TVA Projects: Civil and structural design, page 301:

     The railing at the upstream side also serves as a guide and a support for the manually operated hoist for the flashboard placement and removal.

   • 1996, Sabina Joe, Final Environmental Impace statement: Wisconsin River Basin Hydroelectric Project, Vilas County, Forest County, pages 4-126:

     Although flashboards are designed to fail when reservoir level rises rapidly to an elevation greater than the flashboards, NPI states that most flashboard failures occur as a result of debris or ice hitting the flashboards.

   • 2003, Bobby A. Stewart, Terry Howell, Encyclopedia of Water Science, page 122:

     The discharge pipe for the flashboard riser structure is sized as a culvert ( i.e., boards are out and ditch is flowing full), although the weir is normally sized as though boards are in place.

2. (by extension) A board that controls the flow of any material.
   • 2010, Honghai Liu, Han Ding, Zhenhua Xiong, Intelligent Robotics and Applications, page 522:

     There exists a trapezoidal groove in the bottom of each container and a flashboard fixed in feeding system which match the groove.

   • 2020, Jueming Hua, Lisheng Feng, Thirty Great Inventions of China, page 288:

     […] a flashboard is installed on the outer side of the rear wall to adjust and open-close the seed discharge hole, with the flashboard fastened with a wedge.

3. (physics) A sheet of material that is subjected to an electric pulse or flashover in order to produce plasma.
   • 1990, B N Breizman, B A Knyazev, High-power Particle Beams, page 373:

     The plasma produced by the flashboard was mostly C⁺ and C⁺⁺.

   • 2001, Digest of Technical Papers - Volume 13, page 1842:

     A polyethylene sheet (flashboard) is attached on the anode (aluminum), which acts as the ion source.

   • 2023, Tao Shao, Cheng Zhang, Pulsed Discharge Plasmas: Characteristics and Applications, page 260:

     The time delay between the beginning of the flashboard plasma formation and the HPM pulse generation, determines the plasma density encountered by the microwave pulse.

4. Any automated display that shows temporary information.
   • 1957, The Journal of Air Law and Commerce - Volume 24, page 132:

     Thus encroaching telephone wires, angrily projecting one's arm, an overhanging flashboard, or tree, leaning walls, and overhanging roof, projecting eaves and the shooting of guns have all been regarded as invasions of the superincumbent airspace — the exclusive realm of the landownder.

   • 1972, Arthur R. Hercz, Development of the Field Artillery Observation, page 4:

     With the new flashboard, a good team could concentrate on one target at a time, even in fairly heavy firing .

   • 1973, Dai 11-kai Orinpikku Tōki Taikai, Sapporo 1972, page 398:

     In jumping, a jump recording and display system was newly developed to meet the requirements of this fast-moving event in which the jumper's results were instantaneously displayed on the electronic flashboard after performing a complex score calculation.

   • 1980, Walter Stovall, The Minus Pool, page 298:

     They both looked at the computerized flashboard above the betting windows . It displayed a schedule of all of Sunday's National Football League games.

   1. An electronic display that shows the winning values in various gambling games such as keno or bingo.
      • 1996, Florida Administrative Weekly - Volume 22, Issues 47-52, page 7028:

        The holder of a ticket that contains a match of all the numbers on any one of the Player's Cards to the numbers on the Flashboard card using the 48 Flashboard card numbers and the 49th and 50th Bonus Balls shall be entitled to a prize of $50.

      • 2003, Robert L. Shook, Jackpot!: Harrah's Winning Secrets for Customer Loyalty, page 9:

        In the middle of the table, a roll-down hopper connected to a flashboard. Players bought cards from the dealer, then tried to roll a ball into the hopper in such a way that the flashboard would register a card of a suit and number that would match the cards the players had bought, filling in a four-card sequence.

      • 2011, Minnesota Rules - Volume 9, page 41:

        A breakopen bingo game begins when, in the presence of players, the organization calls and posts, either manually or by use of a flashboard, a predetermined quantity of bingo numbers.

      • 2012, Daivd Cowles, Complete Guide to Winning Keno:

        It's quite possible that the flashboard has one or more burned-out light bulbs—the very same lamps that light up the numbers you needed to catch to turn your losing ticket into a winner!

      • 2023, Wendy Neugent, Pier Pressure:

        He walked back to the closet and pulled out the Bingo flashboard. Mary glanced at the movement of the flashboard and paused.

5. (education) An acrylic board used to display children's work in a school.
6. (education) A board for displaying language material in the classroom, used like a flashcard but potentially holding more information.
   • 1932, The Progressive Teacher, page 18:

     Then he comes forward, takes the flashboard V, and stands in front of the class so that all may see it .

   • 1960, Louis Shores, Instructional Materials: An Introduction for Teachers:

     The tachistoscope is a mechanical flashboard, an apparatus for testing recognition, attention, and memory, which flashes images on a screen for measured periods of time, usually from 1/100 of a second to one second.

   • 1972, Communication Training in Childhood Brain Damage, page 354:

     It is also at this level that each sentence of the experience story is put on a separate strip of paper or flashboard.

   • 2002, Geoffrey Broughton, Christopher Brumfit, Teaching English as a Foreign Language:

     A set of nine or ten flashboards is sufficient for most purposes and avoids the consumption of great quantities of card.

   • 2004, Joseph C. Mukalel, Creative Approaches to Classroom Teaching, page 147:

     Unlike a picture chart the flashboard contains only language material .

7. (historical) A device used in the 1920s for teaching typing skills which provided feedback on which key was pressed by lighting up the corresponding value.
   • 1921, Office Appliances; The Magazine of Office Equipment, page 16:

     There is a regular typewriter keyboard which is in mechanical connection with a scientifically designed, step by step "flashboard." The machine is designed to develop accurate typists through the realization of visual images.

   • 1922 May, “Typewriter Students Aided By "Flashboard" Machine”, in Popular Mechanics, volume 37, number 5, page 696:

     This flashboard also is equipped with the standard layout of letters, signs, etc., each having a white spot under it, but which is conceled by a small shutter.

• half boards