On Friday, March 31, 2017 at 4:42:53 AM UTC-7, Chuck wrote:
>
> 360 ohms is way too little resistance for *any* sort of
> TTL pullup resistor! That apparently got confused with
> the standard *pull down* resistor used to keep an unattended
> TTL input *low*. 360 ohms for a TTL pulldown is
h.
John K
- Original Message -
From: "chuck richards" <chuc...@all2easy.net>
To: <neonixie-l@googlegroups.com>
Sent: Friday, March 31, 2017 10:12 PM
Subject: [neonixie-l] Re: Taylor Edge Nixie Clock Kit
360 ohms is way too little resistance for *any* sort of
TTL pullu
!!
(This is all explained in great detail on page 12 of Don Lancaster's
famous TTL Cookbook)
Original Message
From: neonixie-l@googlegroups.com
To: neonixie-l@googlegroups.com
Subject: [neonixie-l] Re: Taylor Edge Nixie Clock Kit
Date: Thu, 30 Mar 2017 19:38:26 -0700 (PDT)
>
>
>
>
ooglegroups.com
>Subject: RE: [neonixie-l] Re: Taylor Edge Nixie Clock Kit
>Date: Thu, 30 Mar 2017 18:25:39 -0700 (PDT)
>
>>Sorry that it took me so long to get back about this clock problem.
>We have
>>the clock work perfectly now. I have to give my friend Mike all the
>c
I'm a little late to the party, and the discussion between old 74xx versus
74LSxx caught my attention. In most cases, I'd favor the newer 74LS over
the original 74xx. But the resistor values (360 ohm) paint you into using
the older series, because 5V / 360ohms gives you 13.9mA. The value
: dave.do...@comcast.net
To: neonixie-l
Sent: Friday, March 31, 2017 11:55 AM
Subject: [neonixie-l] Re: Taylor Edge Nixie Clock Kit
Sorry that it took me so long to get back about this clock problem. We have
the clock work perfectly now. I have to give my friend Mike all the credit
Sorry that it took me so long to get back about this clock problem. We have
the clock work perfectly now. I have to give my friend Mike all the credit
for figuring this out. It appears that the original clock design schematic
calls for 7400 series ICs but the BOM calls for 74LSXX. Mike has a IC
Sent: Saturday, March 11, 2017 5:28 AM
Subject: [neonixie-l] Re: Taylor Edge Nixie Clock Kit
Here is a copy of the BOM
On Tuesday, March 7, 2017 at 6:37:54 PM UTC-6, dave@comcast.net wrote:
I'm hoping that someone out there can help me with a problem that I am
having with a Taylor
Here is a copy of the BOM
On Tuesday, March 7, 2017 at 6:37:54 PM UTC-6, dave@comcast.net wrote:
>
> I'm hoping that someone out there can help me with a problem that I am
> having with a Taylor Edge clock kit that I built. After completing the kit
> and plugging it in it seemed to be
Take a close look at the signal amplitudes (best to use a scope); if the
resistor values are causing the logic gates to be overloaded [either due to
wrong IC, wrong logic family, wrong resistor value, solder short/open] ,
you will see incorrect levels. Generally, logic-0 will be 200mV or less
t 360 ohms? Have their values been changed on the
board or in the BOM?
John K.
- Original Message -
From: dave.do...@comcast.net
To: neonixie-l
Sent: Friday, March 10, 2017 10:41 PM
Subject: [neonixie-l] Re: Taylor Edge Nixie Clock Kit
Just wanted to update everyone o
What happens if you set all three time switches and the halt/set switch in
the SET position and then push the INCR button, do all counters advance one
step each so that they count properly or do soem still count in the strange
sequence?
I would also make sure that VCC and GND are present on
Just wanted to update everyone on where we are at on this project. One of
the first things that my friend Mike questioned was why are we using 74LS
series instead of 7400. I have order new ICs for everything except the
141s. Here is the last update that I received from him.
Ok, did some
First we need some clarification of the problem, as your original post
contains a discrepancy. At one point you say the 10 minute tube is not
counting correctly, then later you say it is fine. This is probably a typo,
but let's hear the answer.
Nick, the 10s are driven by 92's and the 1s by
as
in one of the customer returns that I analysed). Eeek!!
John K
- Original Message - From: "Nick" <n...@desmith.net>
To: "neonixie-l" <neonixie-l@googlegroups.com>
Sent: Thursday, March 09, 2017 1:37 PM
Subject: [neonixie-l] Re: Taylor Edge Nixie Clock Kit
der bridge to a
different part of the circuit as in one of the customer returns that I
analysed).Eeek!!
John K
- Original Message -
From: "Nick" <n...@desmith.net>
To: "neonixie-l" <neonixie-l@googlegroups.com>
Sent: Thursday, March 09, 2017 1:3
: donderdag 9 maart 2017 4:07
Aan: neonixie-l
Onderwerp: [neonixie-l] Re: Taylor Edge Nixie Clock Kit
...Also, reading your problem description isolates the issue to the 10s digits.
The 10s are driven by 7490s whereas the units are driven by 7492s. Do you have
the right chips in the right places?
I'd
...Also, reading your problem description isolates the issue to the 10s digits.
The 10s are driven by 7490s whereas the units are driven by 7492s. Do you have
the right chips in the right places?
I'd also try swapping round the 74141s between the 10s and units to see if the
problem moves with
If the BOM specified LS, use LS. The Taylor stuff is good - it's more likely
that you have an assembly error.
Randomly changing stuff to see what happens is not a good approach.
I'd start by very thoroughly checking that you have the right components in the
right places, that you don't have
Your question about the TTL type was discussed between my friend and I. He
asked me why I used 74LS instead of 7400. I told him that 74LS00, 74LS90,
and 74LS92 is what was on the BOM for the kit. He also thought that a 7400
may work better. I will try that first and see what happens. Will let
I suspect they're there to "latch-up" the buffer to debounce the switches -
pulling the input to ground with "de-latch" it. - these are o/c buffers,
hence R12, R14 & R16.
Nick
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Clocking problem. I've been looking at the peculiar buffering on the clock
signals (7417 open-collector buffer), and cant come up with a good reason
why R11, R13, and R15 are present. I'd be especially concerned about
unstable operation, as this circuit has positive feedback.
Are you using
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