Thank you SO MUCH! You've solved most of my problems I have right now! Thank you once more ang good luck to you too!
W dniu czwartek, 22 marca 2018 13:23:24 UTC+1 użytkownik John Murphy napisał: > > I am currently working on a very similar project. Here is what I've > learned: > > 1. The IN-9 tubes don't all act properly using a 150V DC switching power > supply (I bought several different models from eBay). The glow of the tube > becomes disconnected from the bottom and "floats" in the middle - this is > not how a bargraph should behave. I have been successful using a full wave > rectifier circuit from 120V mains through a 1:1 isolation power supply > (US). If you have 240V mains, you would need a 2:1 step-down transformer. > I used the KBP307 rectifier instead of discrete diodes. Do NOT try to use > the rectified mains without a transformer. In addition to this being > dangerous, if the DC 0V has a path to earth ground, the rectifier will be > destroyed, and also likely take out other components like the uC. I am > using a Triad VPS230-110 as it's fairly inexpensive. It has a maximum > output current of 220 mA, but for a music visualizer, you won't have full > scale output on all the tubes at the same time - you could enforce this > using code in the microcontroller if you're worried about it. > > 2. Most microcontrollers have a limited number of pins that you can output > PWM on. If you want to drive 16 tubes, you need 16 PWM (or analog out) > pins. I am using two serial octal DACs (LTC1665) to drive the base of the > MJE340 transistors using the circuit in the paper you referenced. DAC > values are set with a synchronous serial stream. The clock and data lines > are common to both DACs and each one gets its own chip select for a total > of 4 digital pins needed to drive 16 tubes. > > 3. If you buy New Old Stock (NOS) tubes, some of them won't initially glow > to full height due to being in storage for so long. They need to be > "burned in" - something about the physics of the cathode tube that I don't > really understand. I have found that driving them at 15mA for about an > hour has been enough. Over that time the glow gradually creeps from about > 1/2 scale to full scale. After that, they all have worked to full scale. > > Have fun! > > > > > > On Wednesday, March 21, 2018 at 3:52:45 PM UTC-4, Mikołaj Walkowiak wrote: >> >> Hello everyone! I'm doing project for college and I've decided to make an >> audio visualiser using IN-9's. The problem is I don't have any idea how to >> power them. I'd like to have 18 tubes for different sound frequenties and >> I'll be using stm34 to calculate the value each tube should show.. >> >> Now, I know I need 140v and 0 - ~~12 mA for 1 tube but that's all I know >> honestly. I think I'll use something like the 0-offset driver found in >> HERE <https://www.die-wuestens.de/rd/IN9-2.pdf> controled by PWM of my >> uC but I honestly have no idea how to power them. Is 140V(or 150V? >> everywhere except there it says 140V) enough even for 18 tubes? If yes is >> it possible to make this kind of supply myself as I can't find anything >> reasonable price-wise with 140V. Do I need to consider anything else? >> > -- 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 post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/88860d78-0796-41bb-91f7-1a9528bb8e6d%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
