The Berlin quantity didactics clock

There are infinite ways to show the time to people, and one of the stranger ways is used by the Berlin-Uhr(R), invented by Dieter Binninger. The clock was installed in 1975 for the first time at the Kurfürstendamm in Berlin-Charlottenburg near the subway station Uhlandstr.

In 1995 the clock was shut down, although in the years before it was not in proper condition, already. The running costs of this clock were around 5000 Euro per year. In 1996 the clock was moved next to the Berlin Europa Center in front of the tourist information, now sponsored by merchants within the center. With this the Europa Center has a second unusual clock besides of the often photographed water clock in the main hall. The small image above is referencing to a full photo of the Berlin-Uhr in front of the Europa Center in March 1998. Where at the Kudamm the clock was activated on both sides, at its current location only one side shows the time. The other side is deactivated. In December 1999 the Berlin-750-Anniversary plate in front of the clock was removed. After 2000 the clock was renovated and got new colored glass with thick black frames, where the yellow glass got more like orange which is noticable when comparing the 1998 photo with a photo made in 2004. This was corrected sometimes later again , as a photo made in 2012 shows. This photo shows also that the clock could use a renovation again.

If there is a Java capable browser in action and a color display available, the current time shown by this clock will look like

The Berlin-Uhr is based on the principles of quantity didactics and with this its the first of its kind. The time is calculated by adding the lit rectangular lamps. The top lamp is a pump which is blinking on/off every two seconds. In the upper line of red lamps every lamp represents 5 hours. In the lower line of red lamps every lamp represents 1 hour. So if in the first line 2 lamps are lit and in the second line 3 lamps its 5+5+3=13h or 1 p.m. In the third line with tall lamps every lamp represents 5 minutes. There are 11 lamps, the 3rd, 6th, and 9th are red indicating the first quarter, half, and the last quarter of the hour. In the last line with yellow lamps every lamp represents 1 minute.

The Java code of this fixed size clock you'll find here.

Before the fall of the Wall there were small desktop versions of the clock visible in the souvenir shops along the Kudamm. If you're shortsighted, this clock is a good way to see the time without glasses even from longer distances, because you can estimate the time from the lit colored lamps even if you can't see them as single lights. (Thats why I'm fan of it.) On the other hand in bright sunlit rooms the time is difficult to see, although the brightness is adjustable. The table version of the clock has a height of around twenty centimeter and the LEDs are very durable, different to the lamps of the original. The table clock also has two alarms with a loud feeping tone. When the electricity supply was gone down for a moment the clock is blinking with all their lamps indicating that it has lost its time.

In the eighties and early nineties even some department stores within Berlin had this table version to sell. Since 1999 I haven't seen any new clock anywhere. In addition to the table version there were also a wall model with bulbs and a picture model with LEDs. All clocks were manufactured within a factory in Berlin-Rudow at the Zwickauer Damm.

After the death of the inventor in the mid nineties the clocks weren't manufactured anymore. The last clock to sell was seen by me in 1999. The clock of the image aside is from 1990. After the turn of the century the clock gone broken by a common error of a blown capacitor, causing a random flicker of the LED's and some scratching of the piezo. When opening the clock, the capacitors are the grey barrel-shaped objects next to the power supply block. The broken capacitor is the smaller one, but its not a bad idea to replace both of them. And so... since the end of February 2003, the clock is working again. (The 235kB picture of the open clock is showing it already with the new capacitors and the right polarization soldered in, the old ones in front of it, and the tools needed for a repair.)

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