Thanks David, that was the kind of information I was looking for. Peter On Sat, Jan 2, 2021 at 9:54 AM David Forbes <[email protected]> wrote:
> 1. There is no reason that you couldn't run nixies in parallel, other than > the maximum current rating of the driver chip. > > 2. Getting Nixies to light up in the dark can be tricky. My Nixie watches > sometimes take a second or so to start glowing in a dark room. A second > activation displays normally. Some people install blue LEDs under each > tube, which should help. > The 74141 has those Zener diodes to protect the 60V transistors when an > invalid code 0xA..0xF is sent to it. The 7441A used a different method to > protect the transistors, by decoding all sixteen possible inputs to turn on > at least one output transistor. > I have never found a need to add bias resistors to a Nixie circuit. Some > feel that it's necessary when multiplexing. They tend to use wires instead > of PC boards to connect the tubes, resulting in high capacitance that > causes timing issues. > My Nixie watches use the TD62083 50V transistor array, which has > commutator diodes that are connected to a 50V tap on the power supply, to > give the same protection that the Zeners in the 74141 give. > > > > > > On Sat, Jan 2, 2021, 6:58 AM peter bunge <[email protected]> wrote: > >> Question 1. Has anyone tried paralleling two or three Nixies from a >> single 74141? >> I am making a working demonstration with a variety of vintage displays >> (Nixie, Dekatron, Numitron, Amperex 8453,etc) that will all count together >> from a common clock. >> >> Question 2. The data sheet for the IN16 says: >> 8. If the indicator is used in such a place that it is not being affected >> by other sources of >> light and the effect of the surrounding energy sources is lessened due to >> the indicator >> being encased in a metal capsule, in order to avoid the possible increase >> in the voltage >> and the ready-time of the indicator (the time it takes for the indicator >> to display the digits), it is recommended that you use artificial lighting >> with a luminosity level of not less than 40 lumens or one of the “comma” >> symbols as a “pilot” electrode with a current >> in its circuit of 0.7—1.5 μΑ. >> which helps explain a question about Nixies that do not fire in the dark. >> What can be done for tubes that do not provide these commas for keep alive >> current (beside shining a light on them). Can a very high resistor from one >> cathode be used? >> >> Question 3. Another section talks about biasing idle cathodes. >> 7. In order to eliminate the glowing halo on idle cathodes, it is >> recommended >> that you provide them with a voltage of plus 60—110 V relative to the >> cathode >> used (indicated). >> Is this what the 60v zeners in the 74141 do? Are pullups required? I need >> some practical tips on connecting the tubes without making the circuit too >> complicated. The 74141 alone seems to work well with the IN16 without >> biasing the comma. >> [image: Nixie driver.JPG] >> >> -- >> You received this message because you are subscribed to the Google Groups >> "neonixie-l" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/45e8cdd7-1737-4797-83f4-6aae78c11ed4n%40googlegroups.com >> <https://groups.google.com/d/msgid/neonixie-l/45e8cdd7-1737-4797-83f4-6aae78c11ed4n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- > You received this message because you are subscribed to the Google Groups > "neonixie-l" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/CAPbqtvfoBYy44903xHKZWfjLsyEXygijfxL3KjGAvaUuFWMSUw%40mail.gmail.com > <https://groups.google.com/d/msgid/neonixie-l/CAPbqtvfoBYy44903xHKZWfjLsyEXygijfxL3KjGAvaUuFWMSUw%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/CAFxqQo%2BV4x%2B%2BzYmo7Vs%3Dt6uN4gMNEj1UrxLAzbCRZDicpfG5OQ%40mail.gmail.com.
