Hi
Yes, I've seen that 400V circuit but it is not one I've followed through
on it.
The reset will always be to zero and then I pulse the tube, e.g. '8' to
'2' is 'reset' 'step' 'step'. Each E1T uses three I/O lines from the
microcontroller: 'HT switch', 'reset' and 'step pulse'. So each E1T can
be individually selected to glow. Then two further I/O lines can switch
the 6.3V heater PSU and the +300V PSU for the whole display. In the
clock as a whole, I started with 62 I/O lines from the SAM and I'm using
60 of them. I step pulse the tubes at 1mS intervals so the eye sees very
little of the steps, in fact, I want to do the opposite which is to
allow the step pulses to be longer apart so the eye sees the tubes stepping.
I've run all of the E1Ts I own and not found any tubes that get
unbearably hot (except when I accidentally plugged one in to 12.6V,
Ooooops, it did survive). At 6.3V all are warm to the hand but not
burning. Given each tube has 2W input power I wonder why some are so
hot? A quick measurement suggests the back of the tube to the acrylic
cover distance will be about 40mm. Heat generation and final operating
temperature is something we will keep an eye on. The heaters are the
bulk of the energy input to the box so 6 * 6.3V * 0.3A = about 12W.
Overall the clock uses < 20W of power and Nick (as the case designer)
knows that passive ventilation for this heat is required.
All good fun
Grahame
On 17/02/2019 23:30, Dekatron42 wrote:
One of the 400V circuits is actually shown on page 172-173 in the
Dance book, just had a look.
Will you be using a preset-circuit for the E1Ts or will you just step
them up to their setting one step at a time?
From experience I know that some of the E1Ts get extremely hot at the
heater in the back, well enough to burn my fingers, not all do though,
so have you checked that there is enough space between the E1T and the
acrylic?
/Martin
--
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]
<mailto:[email protected]>.
To post to this group, send email to [email protected]
<mailto:[email protected]>.
To view this discussion on the web, visit
https://groups.google.com/d/msgid/neonixie-l/cc948685-169b-4322-9949-1629a854d1be%40googlegroups.com
<https://groups.google.com/d/msgid/neonixie-l/cc948685-169b-4322-9949-1629a854d1be%40googlegroups.com?utm_medium=email&utm_source=footer>.
For more options, visit https://groups.google.com/d/optout.
--
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/ebcfa1a9-3fbc-b274-5212-0d477874be5e%40googlemail.com.
For more options, visit https://groups.google.com/d/optout.
