It's a clock that I designed from scratch. Basically, it was an exercise in using (6) 74LS160 synchronous counters. It gets the HHMM set via a bank of (4) thumbwheel switches, and the SS gets zeroed out and clock stopped via another spring-return toggle switch.
It worked so well that I later decided to make it into a low current version in order to be as easy on the backup battery as possible. So, I used all HC and HCT parts. I used 7441 drivers because that is what I have around here. I am not aware that any low-current versions of those drivers were ever manufactured. Indeed, *is* there any modern low-current bcd-to-decimal high voltage ic that provides a one-package 16 pin DIP solution to this requirement? Is there? Please let me know if there is. I am now making up another similar clock, but using 8422 tubes instead of 6844A kind. Just thought if I could power down the 7441/74141 ics when running on backup battery, that would save the bulk of about 60 mA. What low current drivers would you suggest? Thanks again for all of your help! You guys are a great bunch! -Chuck > > >---- Original Message ---- >From: a...@jacobs.us >To: neonixie-l@googlegroups.com >Subject: RE: [POSSIBLE SPAM] Re: [neonixie-l] Yet more 7441, 74141 >questions >Date: Mon, 21 Nov 2011 13:03:23 -0800 > >>Is this a clock that was already built and you have been modifying >for >>lower current use? or is this a clock that you designed from the >>ground-up for low current? If it is the latter, I can't help >wondering >>why there are 74141's in there at _all_. :) >> >>-Adam >> >>On 11/21/2011 10:03 AM, chuck richards wrote: >>> In an effort to build a low-current nixie clock, >>> I tried using all 74HC parts. That works great, >>> but there are still the (6) 7441, or 74141 TTL drivers. >>> >>> How about this idea? When the clock is running on >>> the backup battery with no line power, what if 5 volts >>> Vcc were to be removed from the 7441/74141 drivers? >>> >>> That way, the clock itself would keep time, and the current >>> draw on the battery would be kept as low as possible since >>> only the CMOS ics would be running. >>> >>> Question: If the ground is kept on the 7441/74141 ics >>> and the Vcc lead is disconnected, will that cause any >>> problems for the 74HC160 counters that have their bcd outputs >>> feeding the 7441/74141 bcd inputs? >>> >>> In other words, I am concerned about the possibility of >>> the 7441/74141 having some path that would try to >>> draw excessive current from the inputs when Vcc is >>> disconnected. >>> >>> Is this a good idea to try, or is it a recipe for >>> trashing some HC160 counters? >>> >>> Thanks. Chuck >>> >>> >>> >>> >>> >>> >>> >>> $4.95/mo. National Dialup, Anti-Spam, Anti-Virus, 5mb personal web >space. 5x faster dialup for only $9.95/mo. No contracts, No fees, No >Kidding! See http://www.All2Easy.net for more details! >>> >> >>-- >>You received this message because you are subscribed to the Google >Groups "neonixie-l" group. >>To post to this group, send an email to neonixie-l@googlegroups.com. >>To unsubscribe from this group, send email to >neonixie-l+unsubscr...@googlegroups.com. >>For more options, visit this group at http://groups.google.com/group >/neonixie-l?hl=en-GB. >> >> $4.95/mo. National Dialup, Anti-Spam, Anti-Virus, 5mb personal web space. 5x faster dialup for only $9.95/mo. No contracts, No fees, No Kidding! See http://www.All2Easy.net for more details! -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
