U6DNC Nixie Clock Kits - Sphere Research Corporation

Sphere Research Corporation
3394 Sunnyside Rd., Kelowna, B.C.
V1Z 2V4 CANADA
Contact information:
U6DNC Nixie Clock Kits
Neonixie CPU-based universal 6-digit nixie clocks
Release Date: January 30, 2007
Î STOP AND READ THIS BEFORE GOING
ANY FURTHER!
These kits require and generate high DC
voltages, over 170VDC, which is very
dangerous if not handled correctly. If you do
not have the experience to work with these
voltages, STOP NOW, and return the kit for a
refund.
Sphere Research Corporation
Phone: (250) 769-1834
FAX:
(250) 769-4106
E-Mail: walter2@sphere.bc.ca
URL:
http://www.sphere.bc.ca
You agree by continuing that you are qualified
to work with these dangerous voltages, and do
so entirely at your own risk. You are
responsible for any final use of the product
made from this kit, and accept all
responsibility for enclosing it in a safe
manner to prevent any shock hazard to
users, and for making any AC power
connections in a safe manner. We DO NOT
provide a housing for this product, that is up
to you.
THIS IS NOT A KIT FOR BEGINNERS!
It is designed for advanced experimenters with experience and knowledge about the circuits employed, who are
capable of doing this level of assembly and testing. Once again, if you feel this does not describe you, please
stop and return the kit for a refund. We would prefer to refund your money than have you lying unconscious on
the floor, with your heart stopped, or some similar untimely end.
Software: These kits are based on the Neonixie pre-programmed Atmel CPU, which has copyrighted software.
In buying this kit, you agree not to reverse engineer or copy this code for any reason, but only to use it in this
specific clock kit. If you do not agree with this condition, please return the kit for a refund. Sphere is only a reseller of the code for this specific use, and no other.
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 1
Things you will need to build these kits:
Like any electronic assembly project, some tools are required which are not included with our parts kit. These
items are:
1. A clean, well lit assembly area.
2. A good quality soldering iron, with safety grounded tip. Weller, Hakko and Ungar all make suitable irons.
You will need a sharp, long tipped iron, and a damp cleaning sponge to keep the tip clean. We include high
quality 63/37 rosin core (or water soluble) solder for the assembly, which significantly helps prevent cold
solder joints.
3. Needle nose pliers and diagonal cutters, plus a number 1 Philips screwdriver for some items.
4. Isopropyl alcohol (available at any pharmacy) to clean the flux from the complete board, and Q-tips and a
cloth to do the cleaning. This should be done outside, in a well ventilated area. If water soluble flux solder
is used, the board can be washed clean with running hot water and a small toothbrush. Compressed air is
very handy to dry the board.
5. A digital multimeter capable of measuring to 500VDC, with safe, well insulated leads.
General but VERY IMPORTANT Information:
Please don’t skip over this section, it has important information about every kit that is essential.
PARTS VALUES/BOARD IDENTS: Each kit has a schematic diagram, parts list and a circuit board. Generally,
all will agree in every way, BUT early board revisions may have the wrong value printed in a component
location, or other minor artwork flaw due to design revisions. If a different part is to be used than is printed on
the board art revision, IT WILL BE CORRECTLY PRE-INSTALLED by us before shipment. Do not alter
preinstalled parts on the circuit board.
VARIABLE VALUES: Some parts do not have a specific value on the boards, they are determined by other
circuit issues, like the type of Nixie tube installed, what kind of external AC power supply is used and other
factors, see the schematic and instructions to determine the right value.
FUSE PROTECTION: Any kit with external power has fuse protection of some type. DO NOT defeat this, or fire
safety will be compromised. Use the fuse value or specific polyswitch specified. (a polyswitch is a self-resetting
fuse that looks like a radial disc style yellow capacitor).
OPTIONS: Many boards have SOFTWARE options that can be selected by going through the Neonixe menu,
some MUST be selected for any operation such as tube sequencing, so be sure you have made a valid
selection for every location that has an option. The complete NEONIXE software options document is
attached as an appendix, read over the software settings and options carefully, the combined board
REQUIRES that the tube sequence option be modified.
MODIFICATIONS & EXPERIMENTATION: Most of the advanced clock boards have extra connections and
options for different connections, external timebases, and even prototyping areas. These allow you to easily
modify the kit to better suit yourself, and your own requirements. Keep in mind, only 1 single timebase
(crystal, oscillator, or external source) may be used at any one time in a clock.
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 2
PARTS IDENTIFICATION: All parts have part numbers, values or color codes to identify them. Many different
but equally correct parts can often be used in specific locations, and we may use different parts because of
availability issues. The parts list generally covers the details of what parts, or range of parts can be used. ICs in
particular have wildly varying part identifications, each maker has their own prefix, suffix and number format
wrapped around a common core number. If you are not sure, please email us for clarification, at
walter2@sphere.bc.ca. Color codes are common on resistors, and you should become familiar with that type of
marking. You can go to our website here for a color code decoding chart at the bottom of the page:
http://www.sphere.bc.ca/test/data.html
SOLDERING: The correct way to solder is to clean the tip of your iron, and first insure it has a smooth coating of
solder to transfer heat. Then, heat the part and board with the tip of your iron, and feed the solder to the parts,
which will melt the solder when the lead and pad are hot enough. A well-tinned, clean tip makes this very easy.
There are many good assembly techniques, but the best is usually to insert the part, spread the leads to pull the
part snug to the board, and clip the lead close to the board. Then solder the junction, and no further work is
required. ALWAYS install any solder in Nixies as the LAST STEP in assembling the board. They are very
fragile, and easily broken with handling. It can be hard to thread all the Nixie leads into the board. Sometimes
trimming them evenly to just ½” makes this much easier. Adjust the tube carefully to be sure it is straight in every
axis, and tack solder two leads. Recheck again, and when all if correctly aligned, go ahead and solder each pin
carefully, being careful not to bridge two pads. The pads are small at the nixie tubes and ICs, so be careful, and
be patient. If you are using the nixie tube pads to connect an external tube, use ribbon cable, and note that the
pads are identified by function (digits 0-9 and A for anode), rather than pin numbers.
MODIFICATIONS: You can use many other power supplies, or an external time base (by omitting U7 and U8,
and Y1, then inject a CMOS/TTL compatible logic clock at J8 External Clock, along with a ground return) with this
clock board. Other Nixies can be used in two ways, either wired to the PCB pads normally used for the on-board
tubes, or via a remote display board. Observe that the Nixie Tube pads show the FUNCTION, not the pin
number for ease in doing this. You can also attach different display boards via the 20 pin headers, simply
pull the on-board nixie driver ICs to use this function.
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 3
U6DNC Series Neonixie Microcontroller Clock Kits
U6DNC
Combined clock/display board,
U6NDC (lower) and accessory
LED “back-lighting board”
(upper).
This board performs all
functions, power supply, HV
converter, clock, timebase,
drivers and display. The back
lighting board can be inserted
UNDER the nixies, through the
holes shown in the center of
each tube, to provide a
contrasting color for effect. The
rubber insulator under each
tube must be removed to use
this option.
U6DNC-ND / 6XB5092 / 6XIN17
Split clock/display board set,
U6NDC-ND (upper) and remote
plug-in nixie display, 6XB5092
(lower).
This upper board performs clock
functions, power supply, HV
converter and timebase, while
the remote display contains the
drivers and nixie displays. The
display board supports virtually
all plug in 13 pin vertical display
tubes, such as the B5092/A,
6844/A, 8037, 8421, ZM560M,
ZM10220/22 and similar tubes. It
can also be used to remote wire
any other type to sockets with
ribbon cable.
The bottom-most board is the
6XIN17 remote display, which
supports the miniature IN-17
nixie tubes and drivers.
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 4
Caution: The Microprocessor (UP1) is very static sensitive, install it into the socket as the
last step, and ONLY after you have made all the required tests on the power supply. Ground
yourself to a grounded object before handling the IC, and never touch the board to
something before you have touched it first, to avoid static discharge though the chip.
FIRST: This kit requires an external Power
Supply, you should select that FIRST, and test it
before attempting to assemble and test this kit. A
12VDC or 12VAC wall wart is ideal, with at least a
1A rating, or you can use a source up to 16VAC/DC,
but you will then have to install the secondary onboard 12V regulator to run the HV converter. If you
bought a supply from us, it will be a nominal 12VDC
supply, with a barrel style DC power connector.
Check to confirm it is positive on the center
conductor (may be up to 16VDC if unregulated and
no load), and working before proceeding. Be sure it
mates with the supplied DC power connector at J2.
Using our supplied 12VDC power supply, the on
board 12V regulator and rectifier are not
required, and they are jumpered out at U10 Input
to output), D1 and D5. This routes input power
directly to the internal 12VDC bus.
WHAT DISPLAY?
This kit can interface to many tube types, but the board patterns are tube-specific.
The combined board drives IN-14 nixies, but others with flying leads can be used, IF the pins are matched to the
board layout. Remember that the layout is marked by FUNCTION, not pin number, for your convenience. It is
possible with minor lead changes to run IN-16 tubes in the same layout in all or some (such as seconds)
positions. Check our website below for tube basing information before you attempt a tube change.
http://www.sphere.bc.ca/test/nixie.html
On the remote boards, either sockets or tubes with flying leads can be used, but note that the socket pattern fits
only specific socket types, and a tube does not fit directly into the holes.
WHAT TIMEBASE? This kit supports 4 possible modes, 3 internal, and one external. Internally, either a
simple quartz crystal can be used (Y1), or one of two different temperature stabilized oscillators from Maxim
(DS32KHZ) in SMD or DIP format. Note that in the initial board layouts, the over-sized DIP package interferes
with the J9 header (it can be mounted on the bottom to avoid this interference). This clearance will be fixed on
later revisions. Externally, a remote source of CMOS/TTL compatible 32.768KHz data can be sent to the J8 EXT
clock pin. USE ONLY ONE TIMEBASE SOURCE. The default is crystal Y1, the temp stabilized oscillators
are an upgrade to the kit.
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 5
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 6
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 7
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 8
U6DNC
U6DNC-ND
U6DNC / U6DNC-ND Annotated PARTS LIST:
Shaded parts are on the combined board U6DNC ONLY.
Part Identification
C1, C2, C3, C4,
C5, C6
C7
0.1uF/50V or better bypass Capacitor
C13
0.01-0.1uF/50V or better Capacitor
C10, C12, C15
10uF/16V-22uF/35V Electrolytic
Capacitor
Supercap, 0.1F/5.5VDC or better
C11
Description
0.1uF/50V or better bypass Capacitor
C14
470uF/16VDC or higher Electrolytic
Capacitor
C15
10uF/16V-22uF/35V Electrolytic
Capacitor
0.1uF/50V or better bypass Capacitor
C16, C17
C18
10uF/16V-22uF/35V Electrolytic
Capacitor
C19
470uF/16VDC or higher Electrolytic
Capacitor
C100, C101
0.1uF/50V or better bypass Capacitor
C102
470uF/16VDC or higher Electrolytic
Capacitor
C103
3.3uF-10uF at least 250VDC
C104
D1, D2, D3, D4,
D5, D8
D6
2.2nF film Capacitor
1A/50V or better rectifier, 1N40014007
1N5817 or better Schottky rectifier
D7
ICTE5, 1N6373A, 5V Transorb
Copyright 2004, 2005, 2007 Sphere Research Corporation
Mechanical Identification, Notes
Radial leads, Can be marked .1 or 104, dipped
or molded case.
Radial leads, Can be marked .1 or 104, dipped
or molded case
Radial Leads, used only if AC power input
used, Optional.
Radial Leads, OBSERVE POLARITY!
Can be dipped tantalum or alum. electrolytic
Radial Leads, OBSERVE POLARITY! Stripe is
negative.
Radial Leads, OBSERVE POLARITY!
Alum. Electrolytic, stripe is negative. If a higher
voltage 470uF cap is provided, it goes HERE.
Radial Leads, OBSERVE POLARITY!
Can be dipped tantalum or alum. electrolytic
Radial leads, Can be marked .1 or 104, dipped
or molded case, required only if U10 installed,
Optional
Radial Leads, OBSERVE POLARITY!
Can be dipped tantalum or alum. Electrolytic,
required only if U10 installed, Optional
Radial Leads, OBSERVE POLARITY!
Alum. Electrolytic, stripe is negative. If 2 lower
voltage 470uF caps are provided, one goes
HERE.
Radial leads, Can be marked .1 or 104, dipped
or molded case.
Radial Leads, OBSERVE POLARITY!
Alum. Electrolytic, stripe is negative. If a lower
voltage 470uF cap is provided, it goes HERE
Radial Leads, OBSERVE POLARITY! Stripe is
negative.
Radial Leads, may be blue or red in color.
Plastic or glass, axial leads
Plastic, axial leads, be sure this is the correct
part before installation.
Zener over-voltage protection for 5V supply
rail.
Nixie Clock Kit Instructions
Page 9
D9
D100
D101
1A/50V or better rectifier, 1N40014007
MUR160, UF160 or 1N4937 Ultra-fast
rectifier
T 1 ¾ Green LED
DS1, DS2, DS4,
DS5
NE2 short Neon Lamp
DS3
NE2 short Neon Lamp
F1
RXE075 Polyswitch fuse (looks like
yellow disc capacitor)
RXE030 Polyswitch fuse (looks like
yellow disk)
DC power connector
20 pin male 0.1” pitch header
F100
J2
J9, J10, J11
L100
L101
Ferrite bead on a lead
100 or 150uH 2A toroid choke.
CTX150-1-52 or sim.
LED1
T 1 ¾ Green LED
N1, N2, N3, N4,
N5, N6
R1, R2, R3, R4,
R5, R6
R7
R8, R9, R10, R11
IN-14 Nixie Tube
680K, ¼ W Resistor 5%
499K, ¼ W Resistors 1%
R12, R13
R14, R15, R16
R17
R18
33K, ¼ W Resistors 5%
4.7K Ohm, ¼ W Resistors 5%
470 Ohm, ¼ W Resistor 5%
10 Ohm 2W Flameproof Resistor 5%
R100
R101
R102
33K, ¼ W Resistor 5%
1K, ¼ W Resistors 5%
221K, ¼ W Resistor 1%
R103
R104
Not used
1K Trimpot
R105
10K, ¼ W Resistor 5%
R106
470 Ohms ¼ W Resistor 5%
22K, ½ W Resistors 5%
Copyright 2004, 2005, 2007 Sphere Research Corporation
Install before UP1 is installed.
Plastic or glass, axial leads, Used only if U10
installed, Optional.
MUR/UF160 preferred. Plastic, axial leads.
Flat side is cathode (short lead), align to
square PCB pad. Install plastic spacer
underneath.
Plain neon lamp, Colon indicator, install plastic
spacer underneath. Mounts on Colon subboard, sleeving around indicator may be
useful to reduce reflections on adjacent nixie
tubes.
Plain neon lamp, HV BITE indicator, install
plastic spacer underneath.
Radial Leads, larger disc.
Radial Leads, smaller disc.
Seat firmly to board.
Can be shrouded or unshrouded, not required
on combined board unless remote display
operation is intended. Can be top or bottom
mounted.
Can be any style, single or multi-turn bead.
Mount elevated as shown. RTV under to
anchor the part is useful. Larger value reduces
waste heat.
Flat side is cathode (short lead), align to
square PCB pad. Install plastic spacer
underneath.
Flying leads, trim for easier insertion. Remove
bases if LED back lighting will be used.
Axial Leads, CC: red, red, orange, gold
Elevate above board slightly.
Axial Leads, CC: blue, gray, yellow, gold
Axial Leads, CC: yellow, white, white, orange,
brown. Note that the bottom leads of R9, R10
are used to attach the colon sub-board, do not
cut! Mounts on colon sub-board, note that
early board art has 100K marked.
Axial Leads, CC: orange, orange, orange, gold.
Axial Leads, CC: yellow, violet, red, gold
Axial Leads, CC: yellow, violet, brown, gold
Elevate above the board, CC: brown, black,
black, gold. Can be increased if input voltage is
higher than the default 12VDC, used to
dissipate excess heat from U9.
Axial Leads, CC: orange, orange, orange, gold.
Axial Leads, CC: brown, black, red, gold
Axial Leads, CC: red, red, brown, orange,
brown
May be single or multi-turn, face adjustment
out to outer edge.
Can also be 1%, Axial Leads, CC: brown,
black, orange, gold (5) or or brown black
black, red, brown (1%) or 1002F 1%.
Axial leads. CC: yellow, violet, brown, gold
Nixie Clock Kit Instructions
Page 10
R107
R-Ground
2.2K ¼ W Resistor 5%
1 Megohm ¼ W Resistor 5%
Q1, Q2
Q100
MPSA42 Transistor
IRF820 or sim. MOSFET
Q101
2N2222A or PN2222 Transistor
S1, S2, S3
Pushbutton switches
UP1
Programmed Atmel Microcontroller
U1, U2, U3, U4,
U5, U6
U7
74141 or K155ID1 Nixie Driver
U8
U9
U10
U100
Y1
16 Pin Sockets
8 Pin Socket
40 Pin Sockets
Threaded Spacers
and mating screws
Screws and nuts
Angle brackets &
screws
Ribbon Wire
Solder
Maxim DS32KHZ
32.768KHz TCXO, DIP
Maxim DS32KHZ
32.768KHz TCXO, SMD
LM340T5, 7805CT or sim. 5V
Regulator
LM340T12, 7812CT, or sim. 12V
Regulator
NE555T, LM555N etc., timer
32.768KHz Crystal, may have the
frequency or a code like R38 on it.
6 pieces, under each driver, U1-U6
1 piece under U100
1 piece, under microprocessor UP1
5 pieces, mount under the board with
provided screws.
For U9 and Q100
For the provided remote switch
assembly
4-wire For remote switch assembly.
Water soluble
or
rosin core solder,
as requested. Relevant type is
CIRCLED.
Copyright 2004, 2005, 2007 Sphere Research Corporation
Axial leads. CC: red, red, red, gold
Used to provide a static drain to a metal
cabinet. Optional
Align to case outline on PCB.
Caution, static sensitive, handle with care.
Attach to board with provided screw and nut,
place head on underside to avoid track short.
Board accepts either type, note that flat line is
on the wrong side on early board artwork,
emitter goes to the outside track.
Can also be external switches of any kind,
SPST, Normally Open.
Install in socket, as last operation to avoid
static damage. Check alignment.
Install in 16 pin sockets, nixie drivers.
Optional stabilized TCXO, DIP package
Optional stabilized TCXO, SMD package
Attach to board with mounting hardware.
Used only if raw input power is higher than
12VDC. Optional Jumper input to output
pads if not used.
Use 8 pin dip socket underneath.
Radial Leads. Default timebase.
4-40 tapped, can be used to attach the board
to your own case design.
4-40 or 3mm.
4-40 screws and brackets
1 foot. Can be gray or colored.
63-37 formula, for minimal cold solder joints.
Nixie Clock Kit Instructions
Page 11
6X-series Remote Display Boards Annotated PARTS LIST:
Mounting
hardware
C1, C2, C3, C4,
C5, C6
C7
Stand-offs and screws provided for
board attachment
0.1uF/50V or better bypass Capacitor
DS1, DS2
A1A long neon lamp, with sleeve at
middle to create two lit areas.
NE2 short neon lamp
DS1, DS2, DS3,
DS4
JP1, JP2, JP3
N1, N2, N3, N4,
N5, N6
N1, N2, N3, N4,
N5, N6
R1, R2, R3, R4,
R5, R6
22uF/16VDC or better
20 pin 0.1” pitch headers
IN-17 Nixie Tube on 6XIN17 board
only
B-5092, 8037, ZM1020, 1022, etc.
Nixies on 6XB5092 board only.
22K, ½ W Resistors 5%
R6, R7
330K ¼ W Resistors 5%
R6, R7
249K ¼ W Resistors 1%
Radial leads, Can be marked .1 or 104, dipped
or molded case.
Radial Leads, OBSERVE POLARITY!
Can be dipped tantalum or alum. electrolytic
Used on 6XIN17 board ONLY.
Used on 6XB5092 board ONLY.
Mount with plastic spacer underneath
Can be shrouded or unshrouded.
Flying leads, trim for easier insertion.
Install PC sockets under tubes.
Axial Leads, CC: red, red, orange, gold
Elevate above board slightly. Early artwork
may say 27K.
Axial Leads, CC: orange, orange, yellow, gold
Early boards show 150k.
Used on 6XIN17 board ONLY.
Axial Leads, CC: red, yellow, white, yellow,
brown. Early boards show 100k.
Used on 6X5092 board ONLY.
To activate remote displays, you require BCD data from the main clock board (grouped in decade pairs, hours ,
minutes, seconds, +170VDC and the colon drive. The 20 pin headers provide the BCD data, and the JP4 pads
provide the HV and colon connections. Interconnection between the main clock board and remote display is via
20 pin ribbon cables (watch out for mis-alignment or reversal end for end), and by flying leads between JP4 on
the display board and J13 on the clock board. To run a remote display from a combined board, you need to run
BCD data and a connection from the +170VDC test point (J1), and two wires from the colon outputs. Remove the
Nixie drivers from the combined board to run the remote display.
RIBBON CABLES:
To connect the boards, 20 conductor ribbon cables with a female 20 socket IDC connector on each end
are required. Insure the +5VDC ends (red stripe or other marker) are always aligned between boards!
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 12
SCHEMATIC:
Look at the Schematic of the clock and remote displays before starting work, and be sure
you understand how the clock is designed. The smaller U6DNC-ND version is just a subset of the main
schematic, with the drivers and display tubes deleted. The microprocessor (UP1) (and its crystal clock) do all the
timekeeping and counter control. BCD (Binary coded decimal) data (4 lines) is sent from the microprocessor to
the Nixie driver chips, which can be 74141 or K155ID1 types, which convert the 5V logic to the HV line control
required by the Nixie tube. The 7441 can not be used, as it does not support blanking, which is required in many
modes. Other Nixie tubes can be used and hard wired into the board pads. Note that the pads indicate the
function of the pad, NOT THE PIN NUMBER. A is for Anode, 1-9 and 0 for the specific cathode element, and
DP for decimal points. Tubes like the IN-16 are easy substitutes. The remote display boards are essentially
identical, with the tube footprints being the major difference between them. All the remote boards have 6 tubes,
and display drivers, plus neon lamps for the colons.
POWER SUPPLY CONCEPTS:
To get the required HV to run the IN-14 Nixies, at least +150VDC is
needed, and to insure adequate element coverage, +170-175V is ideal with the supplied 22K anode resistors.
Some tubes need a bit more to give crisp digit focus, and up to +200VDC can be used with no difficulties on most
tubes, but life will be reduced if the tubes are run too bright.
The 12VDC bus is converted to +170VDC by the switching converter formed by 555 timer U100, MOSFET Q100,
and the following rectifier/filter parts on the board. Parts selection is semi-critical, so stick to our specified items to
avoid problems. The HV level is adjusted by measuring the +170VDC test point (J1) to DC common (J5), and
adjusting trimpot R104. If no tubes are present, the voltage can go quite high (over +250VDC), so care must be
used to set it to +170VDC as a starting value. “HV present” is indicated by neon lamp DS3 being lit. +5VDC for
the digital circuitry is provided by regulator U9 via R18, and its presence is indicated by LED1. A keep-alive
+5VDC for the clock is maintained by the supercap C11 via D6, and fed to UP1 and the oscillators. This keepalive voltage must be present for any CPU operation, and it prevents time loss during momentary primary power
interruptions.
JUMPERS/OPTIONS: Jumpers at U10, D1 and D5 are installed (and D2, D4 delted) when the primary
power is a nominal 12VDC, these parts are required if primary power is AC or if it is over 12V average. C18 is
required ONLY if a low drop-out 12VDC regulator is used at U9.
BITE INDICATORS: Because the board is dangerous when excited with HV, a caution light is added,
(DS3), to warn you that HV is applied. This can be very important during troubleshooting. A 5VDC green LED is
also supplied (LED1) which warns when the logic supply is present. A crowbar Zener is across the 5V power
supply to clamp any excess voltage applied by mistake, and as a static shunt. If this part shorts, or is installed
backwards, the 5V bus will never rise above about 0.7VDC, and the FI polyswitch fuse will open (self-resetting
when power is disconnected). The 12VDC to 170V converter has its own polyswitch (F100) to protect that circuit,
and a green LED D101 monitors primary power to the HV converter, it will be ON when primary power is present,
and the F100 polyswitch has not opened.
POLYSWITCH FUSES: These kits use a Polyswitch for low voltage DC protection rather than a glass
fuse. Primary AC line protection is still by a one-shot glass fuse for fire safety within the wall wart. Polyswitches
are conductive as long as the current is at or below their specified holding value, but go essentially open circuit
when the current is too high. They are reset back to proper conducting operation by removing the short, and/ or
resetting the primary power. The 5VDC light will go out when the primary Polyswitch opens. This technique is
used because many assembly problems may create a “short”, and this would be very inconvenient for you if you
had only one glass fuse available. In addition, R18 is a fusible resistor, in series with the 5VDC regulator, it limits
current to the regulator if a problem is present on the 5VDC rail, if it gets hot, remove power, and search for the
problems.
CABLES: Connection to the setting switch assembly is via a short length of ribbon cable, which can simply
be soldered to each end. The remote displays are connected by 3 individual 20 pin ribbon cables, plus at least 3
additional wires for the colons and HV connection. The ribbon cables are designed with redundant parallel pins,
so that cable construction is not affected by many types of mis-alignment and orientation. As long as the
connectors are not plugged in offset, or reversed end-for end, they will work. It is also possible to solder the wires,
if preferred.
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 13
Assembled Combined board Kit
ASSEMBLY STEPS, both U6DNC clock board types:
1. Important Construction Variations:
The headers at J9, J10 and J11 are installed only if you want to attach a remote display, they are optional
on the combined board, and are required on the split version. They can be installed on the top or bottom
side, it does not affect operation or cable design. The DIP version of the temperature compensated oscillator
at U7 (which is an oversized package) can interfere with a top mounted header and cable at J9.
2. Insert and solder all the resistors, if you orient them all in the same direction, checking for the correct
value is much easier. Install the larger polyswitch at F1.
3. Insert and solder the diodes/rectifiers. Observe the correct polarity, the parts have a banded end
(cathode) that must match the banded marking on the circuit board. Note that the input bridge D1, D2, D4
and D5 is NOT normally required (unless an AC power supply is used), and jumpers are normally
installed at D1 and D5. Note that D6 is a schottky rectifier, 1N5817 or similar, and D100 is a fast high
voltage rectifier, type MUR160 or similar. Be careful not to mix these parts up with the other rectifiers,
which may look almost identical. Check these parts carefully after insertion, a mistake here can be
hard to find later, but can cause serious failure.
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 14
4. Insert and solder the IC sockets, note that one end is notched, to mark the similarly notched/marked end
of the ICs themselves (pin 1 end). Be sure the sockets are fully tight to the board (insert, then bend over
the corner pins to make it grip the board). The UP1 microprocessor socket has gold machined pins. A
blue-green ZIF socket is shown in some pictures, but that was used only during prototyping, the normal
socket is the machined pin type (black) shown on the split board picture.
5. Insert all the 0.1uF bypass capacitors and solder them, they can be either white marked with text as
shown or brown dipped radial parts, marked 104. C13 can be either 0.1uF or 0.01uF, not critical, and is
used ONLY with an AC supply. Install the switcher timing capacitor at C104, 2.2nF.
6. Insert and solder the large flat supercap at C11, check polarity carefully, the can is negative (striped end),
the isolated pin is positive.
7. Insert and solder the polarized capacitors, note the polarity, if a can type, it will have the negative side
marked with a stripe. If a dipped tantalum, it may have a line and sometimes a tiny plus sign at the +
terminal. The board has a + marked for the positive side of every capacitor, it is VERY important that all
be installed correct, double check the polarity of every part. C102 and C103 are especially critical, see
the pic below, and note the negative stripes and their orientation:
8. Q100 (MOSFET) can be damaged by static discharge, so handle it carefully, and attach it to the
board with the provided screw and nut, the HEAD should be on the board BOTTOM side, to avoid a short
to the adjacent track. Solder and trim the leads, and attach the toroid choke L101 as shown above, the
leads just reach to the holes. A dab of glue or RTV to anchor the choke is useful. Install the trimpot at
location R104 as shown above, it will be adjusted from the board edge. Install the provided ferrite bead
(has wire leads) at location L100, it may be a big or small bead.
9. Insert and solder the smaller polyswitch fuse at F100 (looks like a small yellow disk capacitor). You can
lift one lead of the polyswitch and insert an ammeter to monitor the HV inverter current consumption if
you have a problem in this area.
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Nixie Clock Kit Instructions
Page 15
10. Insert and solder the transistors Q1 and Q2 (MPSA42/44 high voltage colon drivers), watch for the correct
orientation, the board shows the case outline, they are at the front of the board in the combined version.
Install a 2N2222A or PN2222 at Q101, note the early board art shows the flat on the wring side, install as
shown below, this part will be correctly pre-installed on initial boards. The emitter goes to the outside
track.
11. Install U9, the +5V Voltage Regulator, typically an LM340T5, or 7805T, etc. attach the flange to the board
with a screw and nut, and solder the 3 leads to the board. Double check the large polarized capacitor
orientations in the power supply against the picture below, and note that C13 and C18 are optional, and
not normally required:
12. Install and solder the DC power jack at location J2, unless you have a different way of connecting power
in your system. The wall wart plugs directly to the jack, a clearance hole at the rear of the case (without
touching the jack in any way) is required. Note R18 above, it is a 10 Ohm, 2W flameproof part, or other
larger parts could be used if the supply voltage is higher than normal.
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 16
13. Install and solder the crystal, Y1, next to the microprocessor. It looks like a tiny metal cylinder, with two
leads out one end. It may have the frequency or a code like R38 on it. Either Y1, or U7 or U8 are
required for the clock to run, or an external timing signal attached to J8.
One crystal/osc. Ð required
14. Install and solder the 5V indicator Led at LED1 using an elevator spacer, note that the LED has a flat on
one side of the plastic case, this is the cathode (it’s also the shorter lead), and should go to the square
pad on the board. Leave the LED spaced a bit above the board, too much heat will destroy the LED.
Repeat the process at D101 for the second green LED.
15. Install and solder the short (3AG) Neon lamp at DS3 using a spacer, this is the warning lamp for High
Voltage on the board. Whenever it is lit, dangerous HV is present on the board.
16. Before going further, inspect every solder joint, re-soldering if needed, and completely clean the board.
The assembly is now complete, except for inserting the ICs (which are static sensitive), and the Nixies
(which are very fragile). Solder all vias (the through-holes that do not have a component lead going
through them), to improve the reliability of the board. Install the headers at J9, J10 and J11 if a remote
display is to be used. They can be top or bottom mounted.
17. It is time to do some initial tests. Install the timer IC at U100. Plug the wall wart into jack J2, and apply
power. The green LEDs should both light (5V DC power and HV converter Power), and a voltmeter test
at J7 to ground (J5) should show +5VDC, a test at J6 (RAWDC, the input power bus) should show about
+12VDC, and a test at J1 should show high voltage. DS3 (neon lamp) should be lit, and you can adjust
R104 for +170VDC at J1. If any of these steps is not possible, stop and examine the circuit in
question. You cannot proceed until all of these power tests are satisfactory.
Examine the IN-14 Nixies, they have a bottom spacer pad, and
long leads. Normally, they are mounted flush with the board, and
the spacer pad provides a shock isolating cushion. When
installing them into the board, you need to be sure they are
vertical in all axes (not tilted), and the same height as the other
tubes, for a clean looking display.
When the tubes are correctly facing forward, the one internal lead
with white insulation will be in the pad marked A at the rear.
Examine the tubes and the board, and be sure you understand
the correct orientation of the tube, it has no gap between pins to
aid this, you have to align it for the correct location. The digits
must be forward, and the white insulated pin must be in pad A.
If you intend to use the LED back lighting board under the
tubes, you must remove the white insulator before soldering
the tubes, and use a spacer to raise them all ¼” above the
board.
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 17
18. You can either clip the leads short (about 1/2”), and straighten them for insertion into the board, and feed
the leads into the board one at a time. This is a slow and tedious operation, so be patient, and avoid
rushing, as a mistake here can be very costly in terms of time and money. It is helpful to tack each tube
at one or two pins with the soldering iron before soldering all pins, so that you can be sure all tubes are in
good visual alignment. Use a towel or something soft to cradle the board while installing the tubes, to
avoid breaking the top glass seal. The tubes are easily broken, so be careful at this stage.
19. Clean the connections to the tubes thoroughly when finished, this is very important to prevent leakage
when operating, and unwanted digit illumination.
20. Assemble the 3 pushbutton switches to the remote switch setting board, be sure they are all even and
straight. Attach the two right angle support brackets (they are not symmetrical) to the board so that the
front holes line up with the switches. Add the legend overlay and mount it with two screws. This will
eventually be mounted to your case. Attach the 4 wire ribbon cable to the pads GRSA, this will be
attached to the same pads at area W1 on the main board (G to GND, R to RESET, S to SET, A to
ADVANCE).
21. Assemble the neon lamps (spacers can be used under the lamps to move them forward) and resistors on
the two small colon boards. Note that the bottom resistor lead is used to anchor the board, along with an
added front jumper wire, to the main clock board. There is no difference between boards, either one can
be in either position. Adjust the jumper/lead height to get the exact vertical colon alignment you want
before soldering. You may want sleeving around the lamps to reduce side reflections on the nixie tubes.
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 18
22. Insert the driver ICs into the sockets, watch for correct alignment and that no leads are bent under
the chip. The board and socket have a notch marked, as do the chips, be sure all are aligned correctly.
Note that the microprocessor (UP1) faces to the right, and the drivers to the right (as viewed from the
font), as shown below:
Pin 1 (notch) Orientation Î
23. Discharge yourself to any large metal object, and take the microprocessor from its protective anti-static
bag, and carefully insert it into the socket, watch that the orientation is correct, and that no leads are bent
under the chip.
24. At this point, assembly is complete, and you are ready to connect the power supply and begin testing and
set up of the clock. If you have the split boards, you will also need to connect the units together as per the
circuit board connection chart on the next page.
25. Attach power, and you should see the clock cycle though all the digits 0-9, and then show 12:00:00 (the
combined board will be reversed, don’t worry). It should then begin counting seconds. The clock goes
through the digit cycle only on initial power up, not once the supercap is charged, as it then displays the
stored time. To force the re-cycle, unplug power, and discharge the supercap with a jumper lead, and
then re-attach power. For the combined cock, you will need to reverse the display sequence, that is
OPTION 52 in the Neonixie software menu, see the attached command set for the clock software
for full instructions. In the menu, you can control virtually every aspect of the clock, and it will
store those settings for future operation. The remote switch board must be attached and working
to access those functions.
Cases:
Any case that appeals to you is satisfactory as long as it prevents accidental shock contact with the HV power
supply, and prevents the nixie tubes from being broken. The split board set allows the most flexibility in
packaging, but is more complex to assemble and wire.
Heat:
Nothing in the kit (at least with out power supply adaptor) gets HOT. Everything should be quite touchable and
only Q100 and L101 get a bit warm during operation, and U9 less so. Case ventilation is useful to avoid thermal
build up that may skew timebase operation, especially with the crystal.
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 19
A Word About Grounding:
The boards do not make any connection to ground (chassis) via the mounting holes normally. This is to avoid
any problem in case your power supply happens to make contact with ground for some reason, such as using an
AC wall wart, and grounding the connector to the case.
However, it is not a good idea to float the CMOS processor above ground, as static discharge during time setting
or other handling can cause logic upsets and other problems. For this reason, both the switch sub-assembly and
main board allow for a jumper to a physical chassis ground connection via the mounting stand-offs. The resistor
at R-GROUND is very useful, and works even if you have some kind of power supply return path. The connection
at the switch board (ground jumper) is a hard ground, and your power supply must not be incorrectly returned to
the chassis for it to work.
Ï
Provided Ground Connections
You can use stand-offs (conductive) to heat sink U10 and U9 to your metal chassis if you wish, but DO NOT
ground U100 for any reason, or serious damage will result.
Clock Board Connections:
Origin
J1 (+170VDC)
J2 (Power In)
J3 (ACIN2)
J4 (ACIN1)
J5 (DC Common)
J6 (+DCRAW)
J7 (+5VDC)
J8 (EXT CLOCK)
J9 (Hours)
Method
Test probe
Power supply connector from wall
wart
Wire (optional)
Wire (optional)
Test Probe
Test Probe
Test Probe
Wire (optional)
20-wire Ribbon cable
J10 (Minutes)
20-wire Ribbon cable
J11 (Seconds)
20-wire Ribbon cable
J12 (+Vcc BACKUP)
Test Probe
AC Power Input
AC Power Input
Meter common (ground)
Meter, Internal 12V bus monitor
Meter, +5VDC test point
Remote 32.768KHZ timebase
Hours BCD Data to remote display
Goes to JP3 on remote display.
Minutes BCD Data to remote display
Goes to JP2 on remote display.
Seconds BCD Data to remote display
Goes to JP1 on remote display.
Meter, +4.5VDC keep-alive test point
W1 (Remote Switches)
4-wire ribbon cable, soldered
To remote setting switch board
Copyright 2004, 2005, 2007 Sphere Research Corporation
Destination
Meter, +170VDC test point
To 12VDC input power
Nixie Clock Kit Instructions
Page 20
Nixie Reference Data (bottom views):
IN14:
IN16:
IN17:
B5092, 8037, 8421 and Similar:
Electrolytic Orientation :
Tantalum Capacitor Orientation:
Negative is DOWN (Stripe)
Copyright 2004, 2005, 2007 Sphere Research Corporation
Negative
Positive
Nixie Clock Kit Instructions
Page 21
Troubleshooting:
If you have a problem, FIRST, visually inspect the board for solder bridges, missing or mis-installed parts,
and unsoldered connections. This represents over 90% of all problems. Use a a magnifying glass to
inspect the board, it can really help.
Power:
Everything flows from the power supply, so be sure you have correct +5VDC and +170VDC operation. If these
are failed, suspect reversed diodes or capacitors, or missing jumpers.
J6 is the convenient monitor point for the raw input DC (usually around 12V), it must be present first for anything
else to work. A dead short can cause F1 to open, disconnect power and re-connect to reset F1. The common
point for your measurements is J5.
If the internal bus is good, the LEDs for +5VDC and the HV supply input power should be lit, if not, check those
sections. If D3 is installed backwards, 12VDC will be sent to the 5V circuits, hopefully clamped by D7 to prevent
total destruction of your logic parts. If this has occurred, reverse D3 (check to be sure it is not shorted), and check
D7 to be sure it is not shorted. F1 will open under catastrophic conditions, BUT it cannot prevetn all possible
damage conditions caused by improper assembly, its main purpose is fire safety.
F100 will open if the HV power supply has a catastrophic problem. Be sure the right diode is installed in position
D100, and that C103 and C102 are in the correct way. Adjust R104 for +170-180VDC under load.
You can see the clock timebase running at J8 (32.768KHz). The clock will not run unless the keep-alive voltage
is present (check J12). A reversed diode at D6 or a reversed supercap at C11 can prevent this voltage from
being present. Check that all chips are in their sockets the right way around if you do not see correct operation!
Nixies:
If power is good, but specific nixie problems are seen, check the drivers U1-U6 (revered or bent leads), bad
soldering or incorrect nixie orientation. It is easy to swap drivers to check them. You can also remove the CPU
(with power off), store it in the anti-static foam, and connect the input lines from each driver to ground at the
headers to test a specific nixie and driver. Note that headers are labeled for the remote display, and are reversed
in sequence for the combined board.
If your clock displays backwards (left to right), (combined board), you have to select the reversed option in the
neonixie menu, item 52. See the option lists for setting that function. The remote boards use the default
connections shown on the headers.
Switches:
If your remote switches do not seem to work or work oddly, check your ribbon cable to be sure it is not reversed
at one end. Note that a hard ground to chassis jumper is possible at the switch assembly, this can cause
problems if you have some part of the external power supply grounded improperly.
Mods:
If you have used a different or AC power supply, and added the 12VDC regulator, be sure the 12VDC output is
good! It is used to drive the bus that feeds the 5V and HV supplies.
We hope you had fun building and using this clock, and that you never needed to check this page!
Copyright 2004, 2005, 2007 Sphere Research Corporation
Nixie Clock Kit Instructions
Page 22