The E1T tube you see on the left has been `in the family` for as long as I can remember. Probably my father took it home from work (he worked at the Shell laboratory in Rotterdam) or he bought it in one of the surplus shops in Rotterdam my father and I used to visit every Saturday morning when I was a child. Because it was such a strange and funny
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looking tube we always used to play with it. Being under the assumption that the tube was broken, I was never particularly careful with it, nor did I make any attempt to bring the tube to life. From the commonly available datasheet, I knew that this was not just a display device, but that the tube actually counts pulses and additionally displays the sum. This implies that the tube has a memory of the equivalent of 3. 5 bits! On top of that, the tube even has a provision to generate a carry for the next digit. How did they do it I work at the central Philips Research Laboratory in Eindhoven, Holland. Obviously, the Lab keeps a complete archive of all research reports and papers. Browsing through some old volumes of the Philips Technical Review in the library, I happened to stumble across a paper, which described the E1T tube in great detail [1]. It is one word beautiful! The whole paper reads like a poem, it is so elegant and ingenious; undoubtedly one of the masterpieces of vacuum tube engineering. Unfortunately there does not appear to be a fancy and concise name for the tube. Dieter categorizes the tube as a "beam Deflection Decade Counter Tube" [2]. I would have liked to believe Joris Roehrenbude who categorizes the E1T as a Trochotron [3]. It sounds a hell of a lot more interesting than a "Decade Counter Tube". Unfortunately on further investigation it appears that a Trochotron is really something completely different...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
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The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
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In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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