Use a CD4066 or a modern equivalent. I think it would work if the ohmmeter range (balancing resistor) was chosen >> the Ron of the switch.
I really like the coil tap switches on the radios < 1925 where the contacts are on the surface of the control panel. Dial up the time on four of those... Tom Tom On Mon, Apr 11, 2011 at 3:22 AM, Tidak Ada <[email protected]> wrote: > What about a switched R-2R Network? or use small realy's, driven by > appropriate decade countinglogic to switch individual trimmed resistors. > > eric > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of [email protected] > Sent: zaterdag 9 april 2011 9:07 > To: [email protected] > Cc: [email protected] > Subject: [neonixie-l] Clock readout based on changing resistance Ohmmeter > > I know that some of the group have built clock circuits that would output a > changing frequency to interface with a Nixie frequency counter. I know that > there have been circuits that output current or voltage for analog meters. > What I was thinking of was a clock circuit where the output would be a > programmable resistance to be read on an ohmmeter. I know there are digital > programmable pot ICs. But will any of them output from say 10 ohms to 2400 > ohms in 10 ohm steps? I know this could be done with reed relays and > discrete resistors set up in a decade circuit. > What I was thinking of is I have a couple of very old Wheatstone bridges > from the 1800s. You balance the bridge using either numbered rotary decade > switches that directly read out the unknown resistance or you use shorting > plugs that go into numbered holes to read out the resistance in decades. The > bridge is balanced when the galvanometer is nulled out to a zero reading. > This would make a unique interactive clock. It wouldn't be very practical > but cool. If the switches/plugs were set for a too early or late > time(resistance) the galvanometer would read unbalanced. > You balance the bridge to read the time. This could also be used on direct > reading Ohmmeters as well. I am not sure how much current flows throug th > bridge but the old galvanometers are not very sensitive. > Tim Laing > > -- > You received this message because you are subscribed to the Google Groups > "neonixie-l" group. > To post to this group, send an email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/neonixie-l?hl=en-GB. > > -- > You received this message because you are subscribed to the Google Groups > "neonixie-l" group. > To post to this group, send an email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/neonixie-l?hl=en-GB. > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
