An interesting Pixie tube application...+ Numitrons
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Walter2
Oct 31, 2014, 2:22:40 PM10/31/14
to neoni...@googlegroups.com
I got a question from one list member wanting to use the Pixie tubes we got to display Hexadecimal data.
sadly, nothing simple like turning on the 1 and another digit works, because you cannot show 11, and the 0 appears before the 1 so that TEN looks like 01. 12 through 15 look fine, though.
however, as we were kicking around different ways, it dawned on me that you CAN in fact show all the binary elements of the hex count with no problems, just use 1, 2, 4, 8. The Pixie tube allows this (just put the limiting resistors on the individual cathodes, rather than the common anode side.
the value is just the sum of the elements shown. so, 10 is 2, 8 and 15 is 1,2,4,8. one interesting circuit aspect is that it allows the tubes to be driven right from the bianry counter and a transistor, no bcd-decimal decoder is required. a normal clock can also be made this way.
no idea if this is actually useful to anybody, but it is one of the more interesting possibilities of the Pixie tube, so I thought it was worth sharing. We are almost out of tubes, many thanks to all that got the data and ordered. I DO have a big batch of very low time RCA DR2010 Numitrons with the flat tops, and the smaller DR2100 series tubes, they also make great looking clocks, and can be filtered to any color. I will post them to the site next week, I'm still getting over the flu.
all the best,
walter (walter2 -at- sphere.bc.ca)
sphere research corp. http://www.sphere.bc.ca
sadly, nothing simple like turning on the 1 and another digit works, because you cannot show 11, and the 0 appears before the 1 so that TEN looks like 01. 12 through 15 look fine, though.
however, as we were kicking around different ways, it dawned on me that you CAN in fact show all the binary elements of the hex count with no problems, just use 1, 2, 4, 8. The Pixie tube allows this (just put the limiting resistors on the individual cathodes, rather than the common anode side.
the value is just the sum of the elements shown. so, 10 is 2, 8 and 15 is 1,2,4,8. one interesting circuit aspect is that it allows the tubes to be driven right from the bianry counter and a transistor, no bcd-decimal decoder is required. a normal clock can also be made this way.
no idea if this is actually useful to anybody, but it is one of the more interesting possibilities of the Pixie tube, so I thought it was worth sharing. We are almost out of tubes, many thanks to all that got the data and ordered. I DO have a big batch of very low time RCA DR2010 Numitrons with the flat tops, and the smaller DR2100 series tubes, they also make great looking clocks, and can be filtered to any color. I will post them to the site next week, I'm still getting over the flu.
all the best,
walter (walter2 -at- sphere.bc.ca)
sphere research corp. http://www.sphere.bc.ca
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