An Oscilloscope Clock

For some reason, I have this weird fascination with clocks that are out of the ordinary. The requirement is that they be electronic, and hopefully in kit form so I can assemble it.

This version is based on an oscilloscope tube. The kit was very easy to assemble, although the plastic case had some issues with fitting, and small broken pieces. The actual electronics worked the first time, and are still functioning perfectly after a year.

The SCTV Scope Clock from Cathode Corner is a unique, hand-made timepiece that brings the time to life on a vintage cathode-ray tube. The hours, minutes and seconds glow gently in green numbers formed with a precision circle generator. Driven by a tiny yet powerful Teensy computer, the clock can also display poetry and play games.

The Scope Clock is housed in a laser-cut case made of clear acrylic plastic. The clock case design evokes memories of the old TV sets from days gone by. The plastic version puts the tube and the circuit board on display. A set of four knobs allows adjustment of the display brightness, focus and centering. The large function knob provides quick selection of one of several clock faces, haiku, Pong or Tetris.

The clock faces are designed for simplicity and beauty. The digits are reminiscent of Nixie tubes. Each digit is formed of circles, arcs, ellipses and lines. The extensive use of curves avoids the jagged appearance of the typical vector display.

Tetris uses the two lower knobs as rotation and position controls for the falling block. given the unique characteristics of a vector display, the ‘bucket’ that the blocks are piled into is drawn as one outline object. Each hole in the bucket is drawn separately.

Pong uses the two lower knobs as the paddle controls for the left and right side players. English may be applied to the ball by hitting it near the edge of the paddle. Each game goes up to 11 points.

There are hundreds of haiku available, displayed in a random sequence. Each is credited to its poet. 

The clock is easy to set up and use. The User Manual provides all the necessary guidance.

The Scope Clock uses a precision crystal clock circuit to keep time to within 3 minutes a year. If this isn’t accurate enough for your needs, a USB GPS receiver (GlobalSat BU-353S4) may be plugged in to keep the time accurate to a fraction of a second. A standard CR2032 coin cell keeps the onboard clock running in case of power failure, so the time only needs to be set once for years of operation.

The long-life 3RP1-A CRT has been shown to run for typically 20 years of continuous operation.

The clock is powered by a 12 Volt, 1.5 Amp DC wall adapter. An American, European, UK or universal adapter is provided as needed.