[neonixie-l] Re: DTF104B Group Buy

[Olivier]

Hi Nick,

Count me in for 15 please.

Cheers,
Olivier 

On Tuesday, 7 March 2023 at 6:22:19 am UTC+8 Nicholas Stock wrote:

> Folks, we have secured 500 DTF104Bs, so the $22 price is in effect. Thanks 
> to everyone who emailed. There's still time for others to jump in if they 
> want as I (and one other) chipped in on the number to bring us up to 500. 
> I'll be in touch with everyone individually about address/shipping/payment 
> in due course.
>
> Any questions, then you should know where to reach me.. 
>
> Cheers,
>
> Nick
>
> On Sat, Feb 25, 2023 at 12:16 PM Nicholas Stock  wrote:
>
>> Fellow enthusiasts. I have a vendor (someone I have done business with 
>> before) who wants to sell some DTF104B's (NOS) for $25 dollars each. If you 
>> wish to buy some, then please contact me directly and I can organize.
>>
>> Best,
>>
>> Nick
>>
>

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[neonixie-l] Re: DTF104B Group Buy

[Nicholas Stock]

Folks, we have secured 500 DTF104Bs, so the $22 price is in effect. Thanks
to everyone who emailed. There's still time for others to jump in if they
want as I (and one other) chipped in on the number to bring us up to 500.
I'll be in touch with everyone individually about address/shipping/payment
in due course.

Any questions, then you should know where to reach me..

Cheers,

Nick

On Sat, Feb 25, 2023 at 12:16 PM Nicholas Stock  wrote:

> Fellow enthusiasts. I have a vendor (someone I have done business with
> before) who wants to sell some DTF104B's (NOS) for $25 dollars each. If you
> wish to buy some, then please contact me directly and I can organize.
>
> Best,
>
> Nick
>

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Re: [neonixie-l] Re: IV-9 numitron lifespan

[Dekatron42]

There are a few different datasheets at the bottom of this page: 
https://danyk.cz/avr_num_en.html and they all seem to mention the filament 
voltage starting at 3.15V - how much would this increase lifespan?

/Martin

On Monday, 6 March 2023 at 17:19:31 UTC+1 Benoit Tourret wrote:

> Thats the case on Mose's clock: one (bypassable) diode driving all the 
> "com" pins
>
> Le lundi 6 mars 2023 à 15:35:22 UTC+1, theold...@gmail.com a écrit :
>
>> Using a current limiter sounds like a LOT of circuitry, 7 times the 
>> number of tubes? I simply use a forward biased diode to drop the voltage, 
>> about 0.7 for a standard silicon diode, and about 0.3 for a Schottky. That 
>> requires only one or perhaps two diodes for the whole set of tubes. Perhaps 
>> not as accurate, but definitely a whole lot simpler.
>>
>>  
>>
>>  
>>
>>  
>>
>>  
>>
>> *From:* neoni...@googlegroups.com  *On Behalf 
>> Of *gregebert
>> *Sent:* Monday, March 06, 2023 8:13 AM
>> *To:* neonixie-l 
>> *Subject:* Re: [neonixie-l] Re: IV-9 numitron lifespan
>>
>>  
>>
>> Very good info, Moses.
>>
>>  
>>
>> From that, I would target the  operating current well-below 20mA to 
>> prolong the life of the display. You could use an NPN current-limiter 
>> (driver) driven from 5V TTL logic. Let me know if you need circuit details, 
>> but it's a very simple design (1 NPN + 1 emitter resistor). As a starting 
>> point, a 270 ohm emitter resistor will limit current to 16mA.
>>
>>  
>>
>> Do you hear any noise with your PWM running at 1600Hz ?  If not, I would 
>> stick with PWM and not use the NPN driver, as it's not necessary. As long 
>> as the PWM cycle-time is shorter than the thermal time-constant of the 
>> filament (probably a few milliseconds), you should be fine. I think you can 
>> measure the thermal time-constant of the filament with a phototransistor 
>> and a scope. Starting at a low PWM frequency, the phototransistor will show 
>> fluctuations in the bulb's intensity. As the frequency is increased, you 
>> should see the amplitude decrease towards zero. I've never actually done 
>> this but I'm pretty sure it will work. You have to use a phototransistor 
>> (or photodiode); a CdS photosensor will have too-slow of a response time.
>>
>> On Monday, March 6, 2023 at 2:37:45 AM UTC-3 Moses wrote:
>>
>> The TI CD4511B datasheet lists the lists the *minimum* high level output 
>> (at 5v VDD) of 4.1v but typical is 4.55v, maybe others are different?
>>
>>  
>>
>> https://www.ti.com/lit/ds/symlink/cd4511b.pdf
>>
>> At 4.55v the segment current on the IV-9 is going to be about 25ma. 
>> Typical IV-9 segment current is about 20ma I believe, so that would be a 
>> 25% overdrive.
>>
>>  
>>
>> I've put up a drive voltage vs segment current table on my site, maybe 
>> it's useful to someone: http://www.neonixie.com/IV-9-6D-RR/#tech
>>
>>  
>>
>> I settled with powering the tubes in my designs in one of two ways.. 5.0v 
>> direct with a recommended PWM of about 65% (the 165 (out of 255) value in 
>> the table) OR 5v through a regular silicon diode, dropping the voltage to 
>> about 4.2v at the tube and PWM that to 76%. Both result in a segment 
>> current of 20ma. Don't know if one or the other is better in regards to 
>> lifetime, I was not able to find any official sources of information. I 
>> experimented with driving them using a 3.3v regulator.. but at that voltage 
>> they were a bit dim.
>>
>>  
>>
>> NOTE: The IV-9 datasheet does mention to avoid running the tubes at a 
>> frequency between 105 and 1000 Hz, presumably to avoid mechanical 
>> resonance. I elected to run them at 1600 Hz.
>>
>>  
>>
>> I looked through some of my testing data.. at a segment current of 3mA 
>> the segments are visible, 2mA they are "barely visible" and at 1mA I noted 
>> them as not visible. Keeping the unlit segments warm with a slight current 
>> seems to make the most sense to me. It's all software on my clock so maybe 
>> an option for the next revision.
>>
>>  
>>
>> That's all I know so far.
>>
>>  
>>
>> Regards,
>>
>> -Moses
>>
>> On Saturday, March 4, 2023 at 5:52:05 AM UTC-8 theold...@gmail.com wrote:
>>
>> Hi Chris,
>>
>>  
>>
>> The numitrons are driven by a 4511 decoder, and according to their data 
>> sheets the max. output at that voltage is 4.1 V, so that is well within 
>> specification for the tube. Yes, I agree, lowering the voltage even further 
>> should increase lifespan.
>>
>>  
>>
>> Bill v
>>
>>  
>>
>> *From:* neoni...@googlegroups.com  *On Behalf 
>> Of *Chris
>> *Sent:* Saturday, March 04, 2023 8:19 AM
>> *To:* neonixie-l 
>> *Subject:* [neonixie-l] Re: IV-9 numitron lifespan
>>
>>  
>>
>> Hi,
>>
>> While i am not sure for the IV9 numitrons have a look at the DA2300 
>> lifetime expectancy,
>>
>>
>>
>> Basically reducing the voltage increases the life expectancy 
>> exponentially. 
>>
>> So i usually run my numitrons at 4.5V or lower and have had no issues so 
>> far.
>>
>> On Friday, March 3, 2023 at 8:05:48 PM UTC+1 

Re: [neonixie-l] Re: IV-9 numitron lifespan

[Benoit Tourret]

Thats the case on Mose's clock: one (bypassable) diode driving all the 
"com" pins

Le lundi 6 mars 2023 à 15:35:22 UTC+1, theoldpha...@gmail.com a écrit :

> Using a current limiter sounds like a LOT of circuitry, 7 times the number 
> of tubes? I simply use a forward biased diode to drop the voltage, about 
> 0.7 for a standard silicon diode, and about 0.3 for a Schottky. That 
> requires only one or perhaps two diodes for the whole set of tubes. Perhaps 
> not as accurate, but definitely a whole lot simpler.
>
>  
>
>  
>
>  
>
>  
>
> *From:* neoni...@googlegroups.com  *On Behalf 
> Of *gregebert
> *Sent:* Monday, March 06, 2023 8:13 AM
> *To:* neonixie-l 
> *Subject:* Re: [neonixie-l] Re: IV-9 numitron lifespan
>
>  
>
> Very good info, Moses.
>
>  
>
> From that, I would target the  operating current well-below 20mA to 
> prolong the life of the display. You could use an NPN current-limiter 
> (driver) driven from 5V TTL logic. Let me know if you need circuit details, 
> but it's a very simple design (1 NPN + 1 emitter resistor). As a starting 
> point, a 270 ohm emitter resistor will limit current to 16mA.
>
>  
>
> Do you hear any noise with your PWM running at 1600Hz ?  If not, I would 
> stick with PWM and not use the NPN driver, as it's not necessary. As long 
> as the PWM cycle-time is shorter than the thermal time-constant of the 
> filament (probably a few milliseconds), you should be fine. I think you can 
> measure the thermal time-constant of the filament with a phototransistor 
> and a scope. Starting at a low PWM frequency, the phototransistor will show 
> fluctuations in the bulb's intensity. As the frequency is increased, you 
> should see the amplitude decrease towards zero. I've never actually done 
> this but I'm pretty sure it will work. You have to use a phototransistor 
> (or photodiode); a CdS photosensor will have too-slow of a response time.
>
> On Monday, March 6, 2023 at 2:37:45 AM UTC-3 Moses wrote:
>
> The TI CD4511B datasheet lists the lists the *minimum* high level output 
> (at 5v VDD) of 4.1v but typical is 4.55v, maybe others are different?
>
>  
>
> https://www.ti.com/lit/ds/symlink/cd4511b.pdf
>
> At 4.55v the segment current on the IV-9 is going to be about 25ma. 
> Typical IV-9 segment current is about 20ma I believe, so that would be a 
> 25% overdrive.
>
>  
>
> I've put up a drive voltage vs segment current table on my site, maybe 
> it's useful to someone: http://www.neonixie.com/IV-9-6D-RR/#tech
>
>  
>
> I settled with powering the tubes in my designs in one of two ways.. 5.0v 
> direct with a recommended PWM of about 65% (the 165 (out of 255) value in 
> the table) OR 5v through a regular silicon diode, dropping the voltage to 
> about 4.2v at the tube and PWM that to 76%. Both result in a segment 
> current of 20ma. Don't know if one or the other is better in regards to 
> lifetime, I was not able to find any official sources of information. I 
> experimented with driving them using a 3.3v regulator.. but at that voltage 
> they were a bit dim.
>
>  
>
> NOTE: The IV-9 datasheet does mention to avoid running the tubes at a 
> frequency between 105 and 1000 Hz, presumably to avoid mechanical 
> resonance. I elected to run them at 1600 Hz.
>
>  
>
> I looked through some of my testing data.. at a segment current of 3mA the 
> segments are visible, 2mA they are "barely visible" and at 1mA I noted them 
> as not visible. Keeping the unlit segments warm with a slight current seems 
> to make the most sense to me. It's all software on my clock so maybe an 
> option for the next revision.
>
>  
>
> That's all I know so far.
>
>  
>
> Regards,
>
> -Moses
>
> On Saturday, March 4, 2023 at 5:52:05 AM UTC-8 theold...@gmail.com wrote:
>
> Hi Chris,
>
>  
>
> The numitrons are driven by a 4511 decoder, and according to their data 
> sheets the max. output at that voltage is 4.1 V, so that is well within 
> specification for the tube. Yes, I agree, lowering the voltage even further 
> should increase lifespan.
>
>  
>
> Bill v
>
>  
>
> *From:* neoni...@googlegroups.com  *On Behalf 
> Of *Chris
> *Sent:* Saturday, March 04, 2023 8:19 AM
> *To:* neonixie-l 
> *Subject:* [neonixie-l] Re: IV-9 numitron lifespan
>
>  
>
> Hi,
>
> While i am not sure for the IV9 numitrons have a look at the DA2300 
> lifetime expectancy,
>
>
>
> Basically reducing the voltage increases the life expectancy 
> exponentially. 
>
> So i usually run my numitrons at 4.5V or lower and have had no issues so 
> far.
>
> On Friday, March 3, 2023 at 8:05:48 PM UTC+1 theold...@gmail.com wrote:
>
> I seem to recall there was some discussion on the life expectancy of IV-9 
> numitrons some time ago. 
>
>  
>
> In 2015 I built a number of clocks with these tubes, and they started 
> failing last year. The clock in the picture is on my bench now, the three 
> good tubes were replaced in November last year. So today all 6 tubes will 
> be replaced. I have replaced all 6 tubes on a few other clocks also. One 

RE: [neonixie-l] Re: IV-9 numitron lifespan

[theoldphart2]

Using a current limiter sounds like a LOT of circuitry, 7 times the number of 
tubes? I simply use a forward biased diode to drop the voltage, about 0.7 for a 
standard silicon diode, and about 0.3 for a Schottky. That requires only one or 
perhaps two diodes for the whole set of tubes. Perhaps not as accurate, but 
definitely a whole lot simpler.

 



 

 

 

From: neonixie-l@googlegroups.com  On Behalf Of 
gregebert
Sent: Monday, March 06, 2023 8:13 AM
To: neonixie-l 
Subject: Re: [neonixie-l] Re: IV-9 numitron lifespan

 

Very good info, Moses.

 

>From that, I would target the  operating current well-below 20mA to prolong 
>the life of the display. You could use an NPN current-limiter (driver) driven 
>from 5V TTL logic. Let me know if you need circuit details, but it's a very 
>simple design (1 NPN + 1 emitter resistor). As a starting point, a 270 ohm 
>emitter resistor will limit current to 16mA.

 

Do you hear any noise with your PWM running at 1600Hz ?  If not, I would stick 
with PWM and not use the NPN driver, as it's not necessary. As long as the PWM 
cycle-time is shorter than the thermal time-constant of the filament (probably 
a few milliseconds), you should be fine. I think you can measure the thermal 
time-constant of the filament with a phototransistor and a scope. Starting at a 
low PWM frequency, the phototransistor will show fluctuations in the bulb's 
intensity. As the frequency is increased, you should see the amplitude decrease 
towards zero. I've never actually done this but I'm pretty sure it will work. 
You have to use a phototransistor (or photodiode); a CdS photosensor will have 
too-slow of a response time.

On Monday, March 6, 2023 at 2:37:45 AM UTC-3 Moses wrote:

The TI CD4511B datasheet lists the lists the *minimum* high level output (at 5v 
VDD) of 4.1v but typical is 4.55v, maybe others are different?

 

https://www.ti.com/lit/ds/symlink/cd4511b.pdf

At 4.55v the segment current on the IV-9 is going to be about 25ma. Typical 
IV-9 segment current is about 20ma I believe, so that would be a 25% overdrive.

 

I've put up a drive voltage vs segment current table on my site, maybe it's 
useful to someone: http://www.neonixie.com/IV-9-6D-RR/#tech

 

I settled with powering the tubes in my designs in one of two ways.. 5.0v 
direct with a recommended PWM of about 65% (the 165 (out of 255) value in the 
table) OR 5v through a regular silicon diode, dropping the voltage to about 
4.2v at the tube and PWM that to 76%. Both result in a segment current of 20ma. 
Don't know if one or the other is better in regards to lifetime, I was not able 
to find any official sources of information. I experimented with driving them 
using a 3.3v regulator.. but at that voltage they were a bit dim.

 

NOTE: The IV-9 datasheet does mention to avoid running the tubes at a frequency 
between 105 and 1000 Hz, presumably to avoid mechanical resonance. I elected to 
run them at 1600 Hz.

 

I looked through some of my testing data.. at a segment current of 3mA the 
segments are visible, 2mA they are "barely visible" and at 1mA I noted them as 
not visible. Keeping the unlit segments warm with a slight current seems to 
make the most sense to me. It's all software on my clock so maybe an option for 
the next revision.

 

That's all I know so far.

 

Regards,

-Moses

On Saturday, March 4, 2023 at 5:52:05 AM UTC-8 theold...@gmail.com 
  wrote:

Hi Chris,

 

The numitrons are driven by a 4511 decoder, and according to their data sheets 
the max. output at that voltage is 4.1 V, so that is well within specification 
for the tube. Yes, I agree, lowering the voltage even further should increase 
lifespan.

 

Bill v

 

From: neoni...@googlegroups.com   
mailto:neoni...@googlegroups.com> > On Behalf Of 
Chris
Sent: Saturday, March 04, 2023 8:19 AM
To: neonixie-l mailto:neoni...@googlegroups.com> >
Subject: [neonixie-l] Re: IV-9 numitron lifespan

 

Hi,

While i am not sure for the IV9 numitrons have a look at the DA2300 lifetime 
expectancy,

  

 



Basically reducing the voltage increases the life expectancy exponentially. 

So i usually run my numitrons at 4.5V or lower and have had no issues so far.

On Friday, March 3, 2023 at 8:05:48 PM UTC+1 theold...@gmail.com 
  wrote:

I seem to recall there was some discussion on the life expectancy of IV-9 
numitrons some time ago. 

 

In 2015 I built a number of clocks with these tubes, and they started failing 
last year. The clock in the picture is on my bench now, the three good tubes 
were replaced in November last year. So today all 6 tubes will be replaced. I 
have replaced all 6 tubes on a few other clocks also. One or more segments will 
no longer light up, and I do not 

Re: [neonixie-l] Re: IV-9 numitron lifespan

[gregebert]

Very good info, Moses.

>From that, I would target the  operating current well-below 20mA to prolong 
the life of the display. You could use an NPN current-limiter (driver) 
driven from 5V TTL logic. Let me know if you need circuit details, but it's 
a very simple design (1 NPN + 1 emitter resistor). As a starting point, a 
270 ohm emitter resistor will limit current to 16mA.

Do you hear any noise with your PWM running at 1600Hz ?  If not, I would 
stick with PWM and not use the NPN driver, as it's not necessary. As long 
as the PWM cycle-time is shorter than the thermal time-constant of the 
filament (probably a few milliseconds), you should be fine. I think you can 
measure the thermal time-constant of the filament with a phototransistor 
and a scope. Starting at a low PWM frequency, the phototransistor will show 
fluctuations in the bulb's intensity. As the frequency is increased, you 
should see the amplitude decrease towards zero. I've never actually done 
this but I'm pretty sure it will work. You have to use a phototransistor 
(or photodiode); a CdS photosensor will have too-slow of a response time.

On Monday, March 6, 2023 at 2:37:45 AM UTC-3 Moses wrote:

> The TI CD4511B datasheet lists the lists the *minimum* high level output 
> (at 5v VDD) of 4.1v but typical is 4.55v, maybe others are different?
>
> https://www.ti.com/lit/ds/symlink/cd4511b.pdf
>
> At 4.55v the segment current on the IV-9 is going to be about 25ma. 
> Typical IV-9 segment current is about 20ma I believe, so that would be a 
> 25% overdrive.
>
> I've put up a drive voltage vs segment current table on my site, maybe 
> it's useful to someone: http://www.neonixie.com/IV-9-6D-RR/#tech
>
> I settled with powering the tubes in my designs in one of two ways.. 5.0v 
> direct with a recommended PWM of about 65% (the 165 (out of 255) value in 
> the table) OR 5v through a regular silicon diode, dropping the voltage to 
> about 4.2v at the tube and PWM that to 76%. Both result in a segment 
> current of 20ma. Don't know if one or the other is better in regards to 
> lifetime, I was not able to find any official sources of information. I 
> experimented with driving them using a 3.3v regulator.. but at that voltage 
> they were a bit dim.
>
> NOTE: The IV-9 datasheet does mention to avoid running the tubes at a 
> frequency between 105 and 1000 Hz, presumably to avoid mechanical 
> resonance. I elected to run them at 1600 Hz.
>
> I looked through some of my testing data.. at a segment current of 3mA the 
> segments are visible, 2mA they are "barely visible" and at 1mA I noted them 
> as not visible. Keeping the unlit segments warm with a slight current seems 
> to make the most sense to me. It's all software on my clock so maybe an 
> option for the next revision.
>
> That's all I know so far.
>
> Regards,
> -Moses
> On Saturday, March 4, 2023 at 5:52:05 AM UTC-8 theold...@gmail.com wrote:
>
>> Hi Chris,
>>
>>  
>>
>> The numitrons are driven by a 4511 decoder, and according to their data 
>> sheets the max. output at that voltage is 4.1 V, so that is well within 
>> specification for the tube. Yes, I agree, lowering the voltage even further 
>> should increase lifespan.
>>
>>  
>>
>> Bill v
>>
>>  
>>
>> *From:* neoni...@googlegroups.com  *On Behalf 
>> Of *Chris
>> *Sent:* Saturday, March 04, 2023 8:19 AM
>> *To:* neonixie-l 
>> *Subject:* [neonixie-l] Re: IV-9 numitron lifespan
>>
>>  
>>
>> Hi,
>>
>> While i am not sure for the IV9 numitrons have a look at the DA2300 
>> lifetime expectancy,
>>
>>
>>
>> Basically reducing the voltage increases the life expectancy 
>> exponentially. 
>>
>> So i usually run my numitrons at 4.5V or lower and have had no issues so 
>> far.
>>
>> On Friday, March 3, 2023 at 8:05:48 PM UTC+1 theold...@gmail.com wrote:
>>
>> I seem to recall there was some discussion on the life expectancy of IV-9 
>> numitrons some time ago. 
>>
>>  
>>
>> In 2015 I built a number of clocks with these tubes, and they started 
>> failing last year. The clock in the picture is on my bench now, the three 
>> good tubes were replaced in November last year. So today all 6 tubes will 
>> be replaced. I have replaced all 6 tubes on a few other clocks also. One or 
>> more segments will no longer light up, and I do not see any blackening of 
>> the glass tube (The black you see in the picture is my permanent marker, s 
>> I will not replace the wrong tube when I disconnect the power).
>>
>>  
>>
>> The tubes are driven directly from a 4511 chip on a 5V power line.
>>
>>  
>>
>> There does not seem to be any order in which they fail, so I do not have 
>> the feeling that any of the tubes are significantly impacted by thermal 
>> stresses from flashing on and off. I would say based on my experience with 
>> them, the expected lifespan is about 7 years of continues use.
>>
>>  
>>
>> Bill v
>>
>> -- 
>> You received this message because you are subscribed to the Google Groups 
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