| Author |
Message |
|
|
 Posted: Aug 07, 2006 - 09:35 AM |
|
Joined: Jul 20, 2006
Posts: 3
|
|
Thanks for your reply, I will probably now just follow your circuit exactly to avoid complications.
I've been looking for some of the parts for your circuit and can't seem to find the inductor (TE2058).
I am from New Zealand and some parts are hard to find so will probably just import them all from a usa online store, do you know any that carry most of the parts I will need?
Also, are the resistors used just regular 1/4watt ones?
Sorry for all the questions.
Thanks |
|
|
| |
|
|
|
|
|
|
Posted: Aug 07, 2006 - 10:32 AM |
|
Joined: May 26, 2004
Posts: 2538
Location: Las Vegas, Nevada
|
|
|
Quote:
I've been looking for some of the parts for your circuit and can't seem to find the inductor (TE2058).
I am from New Zealand and some parts are hard to find so will probably just import them all from a usa online store, do you know any that carry most of the parts I will need?
You should be able to find everything between Digi-Key and Mouser. Mouser has the HV5812 and Digikey has the AVR and the inductor. Everything else comes from either. You can compare prices between them and save a little, but note Digikey's small order surcharge will probably make it cheaper to give them most of the order.
The HV5812 comes in three packages - 28 pin 0.6" wide DIP, 28 pin 0.3" wide surface mount SO-28, and 28 pin square J-lead, your choice. The chips in my photos are the square J-lead package, which is quite compact and for which you can get a socket. (Memo to self: post a diagram of the pinout for this socket).
For the inductor, you'll find the TE2058 listed as an Alfa-Mag part - that's the Digikey stock number. As an alternative, I've also used the Coilcraft DO3316P-224, which is smaller. It's a surface mount part but not hard to solder to a couple of wires on a breadboard. You have a local distributor for Coilcraft, but they're generous with samples so you may get one free if you ask. The TE2058 is also a surface mount part but it's easy to unhook the wire ends from the base and thread them through holes, or else the TE2103 is the same thing designed for through-hole.
Quarter watt resistors are fine, everywhere. Be sure and use a UF4007 (ultra fast) diode for the HV rectifier, as a standard IN4007 will be very inefficient.
What tubes are you planning to use? Different tubes take different amounts of current. Let me know what you have and I'll work out the tweaks for high voltage and anode resistors. |
|
|
| |
|
|
|
|
|
|
Posted: Aug 07, 2006 - 10:42 AM |
|
Joined: May 26, 2004
Posts: 2538
Location: Las Vegas, Nevada
|
|
Here is a TOP VIEW of the PLCC-28 socket, for the J-lead version of the HV5812. The pins are on a 0.1" grid for easy prototyping but note that they don't come out in the order you intuitively think they should.
Again, this is a TOP VIEW. For wiring up from underneath, draw yourself a mirror image, or risk being horribly confused.
Also, once the chip goes in this socket it's darn near impossible to get it out again without a special tool. For this reason, the socket has a hole in the bottom. Drill a matching hole through your board, before you wire it up, so that you can push the chip out from underneath if you need to. |
|
|
| |
|
|
|
|
|
|
Posted: Aug 07, 2006 - 04:28 PM |
|
Joined: May 26, 2004
Posts: 2538
Location: Las Vegas, Nevada
|
|
| I should have mentioned that you can also use the Maxim MAX6921 in place of the HV5812 - it's practically identical with the same pinout. I don't know where to get it, though. It's not listed at Digikey. Also, it doesn't come in 28 pin DIP, only in SO28 and PLCC. |
|
|
| |
|
|
|
|
|
|
Posted: Aug 08, 2006 - 08:11 AM |
|
Joined: Jul 20, 2006
Posts: 3
|
|
|
|
|
|
|
|
Posted: Aug 08, 2006 - 11:19 PM |
|
Joined: May 26, 2004
Posts: 2538
Location: Las Vegas, Nevada
|
|
That Pulse Engineering inductor should work fine. It surprises me how inductors from different companies look so similar ... I suspect they are, in fact, the same, made in the same factory, just with a different name on the packet.
For IN-12 you should use 22k anode resistors and 180V.
For a temperature sensor, I'd use something like a TMP100 ($2.13 from Mouser) as an I2C device on PC4/PC5. In my schematic PC4 is used as an LED driver and PC5 is a 1Hz test point, but both can easily be moved to spare pins. The TMP100 delivers a 12-bit temperature directly in sixteenth-degrees C, so 25.5 degrees C comes in as 0x198. I might add a little code to the project to include that function.
I'd ask in the general AVR forum about that programmer. I've never used one but many other people will have, and will give you a fair opinion. |
|
|
| |
|
|
|
|
|
|
Posted: Nov 20, 2006 - 02:40 PM |
|
Joined: Jul 02, 2002
Posts: 66
Location: Vienna
|
|
Hi Peret
Thank you verry much for this brilliant article!
I recently built a dekatron clock and had a problem
with the hv coil, the cory wasn't powerfull enough.
Altough everything worked it drew 1.8Amps and the poor
fet got so hot you could get burned if touching too long (in fact i got burned,...).
Then I took a slightly bigger core and made another coil.
Altough both had 1miliHenry the circuit just drew 100mA and
the fet stayed cold.
Cheers
Michael |
|
|
| |
|
|
|
|
|
|
Posted: Jan 19, 2008 - 05:17 AM |
|
Joined: Apr 19, 2006
Posts: 19
|
|
| I am also working on a nixie clock. if using an external 60hz pulse (mains freq) would it be possible to use AVRGCC instead of ASM? It seems to me, the way you do things the only section of code that requires the code to be in assembly for a tightly timed loop is the HV section. |
|
|
| |
|
|
|
|
|
|
Posted: Jan 21, 2008 - 07:01 PM |
|
Joined: May 26, 2004
Posts: 2538
Location: Las Vegas, Nevada
|
|
| You could use GCC whether you use the 60Hz or the crystal - it's a matter of personal choice, and what you're comfortable with. If you do it in GCC, why not post your code? |
|
|
| |
|
|
|
|
|
|
Posted: Jan 21, 2008 - 11:08 PM |
|
Joined: Apr 19, 2006
Posts: 19
|
|
Sure. I will post my code when I am done, It might be a while though  . I was more concerned with the ability to have very tightly timed loops with assembly that I would not be able to reproduce with C. That and I only know assembly for the 6502 processor. By the way, Is there any thing I need to know about IN-8 tubes? |
|
|
| |
|
|
|
|
|
|
Posted: Jan 21, 2008 - 11:19 PM |
|
Joined: May 26, 2004
Posts: 2538
Location: Las Vegas, Nevada
|
|
| There are no tightly timed loops in my code, really. The voltage regulator is an interrupt routine and although I took care to keep it short, the ADC conversion that triggers it takes 100 times longer than the code. The 1 sec timing interrupt isn't critical either, as long as you don't miss one. What does become noticeable is if the multiplex rate varies, which shows up as digits flickering. To avoid this you absolutely positively must not miss a 2 millisec timing slot. In a simple design like mine there's nothing that could take long enough, but if you have (for example) an I2C clock chip, reading the clock by I2C can delay things by a millisec and believe it or not, the eye will notice the flicker caused by a single 1ms change in the mux rate. |
|
|
| |
|
|
|
|
|
|
Posted: Jan 21, 2008 - 11:35 PM |
|
Joined: Nov 01, 2005
Posts: 6324
Location: Hilversum - the Netherlands
|
|
|
Quote:
By the way, Is there any thing I need to know about IN-8 tubes?
Not much really. Except that the 5 is made with an upside down 2. The IN8-2 has a decent 5 
My Nixiepages are most in Dutch, but you may find something interesting there: http://www.aplomb.nl/TechStuff/NixNies/NixNies.html
There are three pages, but to switch pages, you have to go back to the top of a page .... sorry for that
Nard |
_________________
Dragon broken ? Or problems with the Parallel Port Programmer ? Scroll down on my projects-page http://www.aplomb.nl/TechStuff/TechStuff.html for tips
|
| |
|
|
|
|
|
|
Posted: Jan 22, 2008 - 02:03 AM |
|
Joined: Apr 19, 2006
Posts: 19
|
|
|
Plons wrote:
Except that the 5 is made with an upside down 2. The IN8-2 has a decent 5
Nope either its the other way around, or they both have good 5s. http://www.flickr.com/photos/mmm_linux/2210199391/ Sorry that its a cell phone pic. I was more wondering what resistor value I should use. |
|
|
| |
|
|
|
|
|
|
Posted: Jan 22, 2008 - 02:18 AM |
|
Joined: May 26, 2004
Posts: 2538
Location: Las Vegas, Nevada
|
|
| Tubes of that size generally specify 2 or 2.5mA typical average cathode current, but that will be rather bright. The minimum current is the value where the cathode flickers, or isn't lit over its whole area. For multiplexing 4 or 6 tubes you can use more current, up to about 10mA. You can use considerably less, for longer life, as long as the peak current is enough to light the cathodes properly. More current will just make them brighter. To work out a suitable resistor value, subtract the sustaining voltage (usually about 120V) from the supply voltage (usually about 170V), divide by the desired current in mA, and the result is the resistance in kilohms. EG for 5mA, (170-120)/5 = 50/5 = 10k. |
|
|
| |
|
|
|
|
|
|
Posted: Jan 22, 2008 - 05:48 AM |
|
Joined: Apr 19, 2006
Posts: 19
|
|
| Ah, that's what I wanted to know. If I may ask, why do you use the difference between the supply from the sustain voltage? |
|
|
| |
|
|
|
|
|
|
Posted: Jan 22, 2008 - 01:47 PM |
|
Joined: Nov 01, 2005
Posts: 6324
Location: Hilversum - the Netherlands
|
|
|
mmmlinux wrote:
Plons wrote:
Except that the 5 is made with an upside down 2. The IN8-2 has a decent 5
Nope either its the other way around, or they both have good 5s. http://www.flickr.com/photos/mmm_linux/2210199391/ Sorry that its a cell phone pic. I was more wondering what resistor value I should use.
I apologize for the confusion: the IN14 has an upside-down 2 as 5. IN8 and IN8-2 are OK.
Nard |
_________________
Dragon broken ? Or problems with the Parallel Port Programmer ? Scroll down on my projects-page http://www.aplomb.nl/TechStuff/TechStuff.html for tips
|
| |
|
|
|
|
|
|
Posted: Jan 22, 2008 - 05:51 PM |
|
Joined: May 26, 2004
Posts: 2538
Location: Las Vegas, Nevada
|
|
|
Quote:
why do you use the difference between the supply from the sustain voltage?
A neon tube behaves something like a zener diode - in fact, they were used as voltage regulators in the days of tubes. Once it strikes, it maintains a relatively constant voltage across it (the "sustaining" voltage). So the voltage across the resistor is the difference between the supply voltage and the sustaining voltage, and it's this difference voltage that pushes the current through.
Here are the characteristics of the IN8. The translation leaves something to be desired. The line "from the supplier of pulse voltage ... 1mA" means the average multiplexed current should be 1mA, eg 6 multiplexed tubes get 6mA peak. I tried to attach an ancient Burroughs data sheet from the 1960s, but the server said it's too big. Maybe I can screen-capture a section out of it. |
|
|
| |
|
|
|
|
|
|
Posted: Jan 24, 2008 - 04:20 AM |
|
Joined: Jan 03, 2004
Posts: 1637
Location: Apalachin, NY, USA
|
|
|
peret wrote:
There are no tightly timed loops in my code, really.
...
What does become noticeable is if the multiplex rate varies, which shows up as digits flickering.
Well, so far, I have the HV regulation and multiplexing implemented entirely in C (GCC, WinAVR) on my prototype.
My Second Nixie Tube Clock Protoboard - on Flickr
Don |
|
|
| |
|
|
|
|
|
|
Posted: Jan 25, 2008 - 04:48 AM |
|
Joined: Apr 19, 2006
Posts: 19
|
|
| Are those IN-8-2 tubes? If not what are you using for sockets? |
|
|
| |
|
|
|
|
|
|
Posted: Jan 26, 2008 - 05:44 AM |
|
Joined: Jan 03, 2004
Posts: 1637
Location: Apalachin, NY, USA
|
|
|
mmmlinux wrote:
Are those IN-8-2 tubes? If not what are you using for sockets?
Yes, those are IN-8-2 tubes - soldered directly to PCB but with a slight space between the PCB and the bottom of the tube.
I'd be very interested if someone has come up with a good scheme for mounting IN-8 nixie tubes on a PCB.
Don |
|
|
| |
|
|
|
|
|
FAQ
Search
Register
Log in to check your private messages
Log in
Maximize
RSS
