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Cactus - a thyratron and a dekatron fight for control of a relay, producing pleasent syncopations
Thyratrons and Dekatrons are two types of tubes [valves, Brit.] which had almost no application in consumer electronics. Thyratrons were used for timing, generating pulses, controlling power, and so on. Dekatrons were used in counting circuits and as numerical display. Neither type is really a vacuum tube. They are filled with special gas blends which give them electrical characteristics very different from a radio or amplifier tube. In this circut, two thyratrons (type number 884) produce pulses. The dekatron counts pulses from one of the thyratrons. Every time the dekatron counts off ten pulses, it irritates the other thyratron into pausing. The (second) paused thyratron changes the firing voltage of the first thyratron (the one running the dekatron). The second thyratron also pulses a relay coil which blinks a red light. If the control knobs are set just right, the two thyratron circuits will fall out of synch with each other, but still influence when the other fires (generates a pulse). If this delicate proposition is achieved, the clicking of the relay coil will produce syncopated and unpredictable rhythms and timbres.
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