U6DNC Nixie Clock Kits URL - Sphere · 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

Copyright 2004, 2005, 2007 Sphere Research Corporation Nixie Clock Kit Instructions Page 1

Sphere Research Corporation

U6DNC Nixie Clock Kits

Sphere Research Corporation3394 Sunnyside Rd., Kelowna, B.C.V1Z 2V4 CANADAContact information:

Phone: (250) 769-1834 FAX: (250) 769-4106 E-Mail: [email protected] URL:

http://www.sphere.bc.ca

Neonixie CPU-based universal 6-digit nixie clocks Release Date: January 30, 2007

STOP AND READ THIS BEFORE GOINGANY FURTHER!

These kits require and generate high DCvoltages, over 170VDC, which is verydangerous if not handled correctly. If you donot have the experience to work with thesevoltages, STOP NOW, and return the kit for arefund.

You agree by continuing that you are qualifiedto work with these dangerous voltages, and doso entirely at your own risk. You areresponsible for any final use of the productmade from this kit, and accept allresponsibility for enclosing it in a safemanner to prevent any shock hazard tousers, and for making any AC powerconnections in a safe manner. We DO NOTprovide a housing for this product, that is upto you.

THIS IS NOT A KIT FOR BEGINNERS!

It is designed for advanced experimenters with experience and knowledge about the circuits employed, who arecapable of doing this level of assembly and testing. Once again, if you feel this does not describe you, pleasestop and return the kit for a refund. We would prefer to refund your money than have you lying unconscious onthe 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 thisspecific clock kit. If you do not agree with this condition, please return the kit for a refund. Sphere is only a re-seller of the code for this specific use, and no other.


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. Theseitems 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 highquality 63/37 rosin core (or water soluble) solder for the assembly, which significantly helps prevent coldsolder 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 solderis used, the board can be washed clean with running hot water and a small toothbrush. Compressed air isvery 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 componentlocation, or other minor artwork flaw due to design revisions. If a different part is to be used than is printed onthe board art revision, IT WILL BE CORRECTLY PRE-INSTALLED by us before shipment. Do not alterpreinstalled parts on the circuit board.

VARIABLE VALUES: Some parts do not have a specific value on the boards, they are determined by othercircuit issues, like the type of Nixie tube installed, what kind of external AC power supply is used and otherfactors, 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 firesafety will be compromised. Use the fuse value or specific polyswitch specified. (a polyswitch is a self-resettingfuse 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 validselection for every location that has an option. The complete NEONIXE software options document isattached as an appendix, read over the software settings and options carefully, the combined boardREQUIRES that the tube sequence option be modified.

MODIFICATIONS & EXPERIMENTATION: Most of the advanced clock boards have extra connections andoptions for different connections, external timebases, and even prototyping areas. These allow you to easilymodify 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.


PARTS IDENTIFICATION: All parts have part numbers, values or color codes to identify them. Many differentbut equally correct parts can often be used in specific locations, and we may use different parts because ofavailability issues. The parts list generally covers the details of what parts, or range of parts can be used. ICs inparticular have wildly varying part identifications, each maker has their own prefix, suffix and number formatwrapped around a common core number. If you are not sure, please email us for clarification, [email protected]. Color codes are common on resistors, and you should become familiar with that type ofmarking. 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 ofsolder 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 thepart snug to the board, and clip the lead close to the board. Then solder the junction, and no further work isrequired. ALWAYS install any solder in Nixies as the LAST STEP in assembling the board. They are veryfragile, and easily broken with handling. It can be hard to thread all the Nixie leads into the board. Sometimestrimming them evenly to just ½” makes this much easier. Adjust the tube carefully to be sure it is straight in everyaxis, and tack solder two leads. Recheck again, and when all if correctly aligned, go ahead and solder each pincarefully, being careful not to bridge two pads. The pads are small at the nixie tubes and ICs, so be careful, andbe patient. If you are using the nixie tube pads to connect an external tube, use ribbon cable, and note that thepads 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 thisclock board. Other Nixies can be used in two ways, either wired to the PCB pads normally used for the on-boardtubes, or via a remote display board. Observe that the Nixie Tube pads show the FUNCTION, not the pinnumber for ease in doing this. You can also attach different display boards via the 20 pin headers, simplypull the on-board nixie driver ICs to use this function.


U6DNC Series Neonixie Microcontroller Clock Kits

U6DNC

Combined clock/display board,U6NDC (lower) and accessoryLED “back-lighting board”(upper).

This board performs allfunctions, power supply, HVconverter, clock, timebase,drivers and display. The backlighting board can be insertedUNDER the nixies, through theholes shown in the center ofeach tube, to provide acontrasting color for effect. Therubber insulator under eachtube must be removed to usethis option.

U6DNC-ND / 6XB5092 / 6XIN17

Split clock/display board set,U6NDC-ND (upper) and remoteplug-in nixie display, 6XB5092(lower).

This upper board performs clockfunctions, power supply, HVconverter and timebase, whilethe remote display contains thedrivers and nixie displays. Thedisplay board supports virtuallyall plug in 13 pin vertical displaytubes, such as the B5092/A,6844/A, 8037, 8421, ZM560M,ZM10220/22 and similar tubes. Itcan also be used to remote wireany other type to sockets withribbon cable.

The bottom-most board is the6XIN17 remote display, whichsupports the miniature IN-17nixie tubes and drivers.


Caution: The Microprocessor (UP1) is very static sensitive, install it into the socket as thelast step, and ONLY after you have made all the required tests on the power supply. Groundyourself to a grounded object before handling the IC, and never touch the board tosomething before you have touched it first, to avoid static discharge though the chip.

FIRST: This kit requires an external PowerSupply, you should select that FIRST, and test itbefore attempting to assemble and test this kit. A12VDC or 12VAC wall wart is ideal, with at least a1A rating, or you can use a source up to 16VAC/DC,but you will then have to install the secondary on-board 12V regulator to run the HV converter. If youbought a supply from us, it will be a nominal 12VDCsupply, with a barrel style DC power connector.Check to confirm it is positive on the centerconductor (may be up to 16VDC if unregulated andno load), and working before proceeding. Be sure itmates with the supplied DC power connector at J2.

Using our supplied 12VDC power supply, the onboard 12V regulator and rectifier are notrequired, and they are jumpered out at U10 Inputto output), D1 and D5. This routes input powerdirectly 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 theboard layout. Remember that the layout is marked by FUNCTION, not pin number, for your convenience. It ispossible 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 fitsonly 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 asimple 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 interfereswith the J9 header (it can be mounted on the bottom to avoid this interference). This clearance will be fixed onlater revisions. Externally, a remote source of CMOS/TTL compatible 32.768KHz data can be sent to the J8 EXTclock pin. USE ONLY ONE TIMEBASE SOURCE. The default is crystal Y1, the temp stabilized oscillatorsare an upgrade to the kit.





U6DNC U6DNC-ND

U6DNC / U6DNC-ND Annotated PARTS LIST:

Shaded parts are on the combined board U6DNC ONLY.

Part Identification Description Mechanical Identification, NotesC1, C2, C3, C4,C5, C6

0.1uF/50V or better bypass Capacitor Radial leads, Can be marked .1 or 104, dippedor molded case.

C7 0.1uF/50V or better bypass Capacitor Radial leads, Can be marked .1 or 104, dippedor molded case

C13 0.01-0.1uF/50V or better Capacitor Radial Leads, used only if AC power inputused, Optional.

C10, C12, C15 10uF/16V-22uF/35V ElectrolyticCapacitor

Radial Leads, OBSERVE POLARITY!Can be dipped tantalum or alum. electrolytic

C11 Supercap, 0.1F/5.5VDC or better Radial Leads, OBSERVE POLARITY! Stripe isnegative.

C14 470uF/16VDC or higher ElectrolyticCapacitor

Radial Leads, OBSERVE POLARITY!Alum. Electrolytic, stripe is negative. If a highervoltage 470uF cap is provided, it goes HERE.

C15 10uF/16V-22uF/35V ElectrolyticCapacitor

Radial Leads, OBSERVE POLARITY!Can be dipped tantalum or alum. electrolytic

C16, C17 0.1uF/50V or better bypass Capacitor Radial leads, Can be marked .1 or 104, dippedor molded case, required only if U10 installed,Optional

C18 10uF/16V-22uF/35V ElectrolyticCapacitor

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 lowervoltage 470uF caps are provided, one goesHERE.

C100, C101 0.1uF/50V or better bypass Capacitor Radial leads, Can be marked .1 or 104, dippedor molded case.


Radial Leads, OBSERVE POLARITY!Alum. Electrolytic, stripe is negative. If a lowervoltage 470uF cap is provided, it goes HERE

C103 3.3uF-10uF at least 250VDC Radial Leads, OBSERVE POLARITY! Stripe isnegative.

C104 2.2nF film Capacitor Radial Leads, may be blue or red in color.D1, D2, D3, D4,D5, D8

1A/50V or better rectifier, 1N4001-4007

Plastic or glass, axial leads

D6 1N5817 or better Schottky rectifier Plastic, axial leads, be sure this is the correctpart before installation.

D7 ICTE5, 1N6373A, 5V Transorb Zener over-voltage protection for 5V supplyrail.


Install before UP1 is installed.D9 1A/50V or better rectifier, 1N4001-

4007Plastic or glass, axial leads, Used only if U10installed, Optional.

D100 MUR160, UF160 or 1N4937 Ultra-fastrectifier

MUR/UF160 preferred. Plastic, axial leads.

D101 T 1 ¾ Green LED Flat side is cathode (short lead), align tosquare PCB pad. Install plastic spacerunderneath.

DS1, DS2, DS4,DS5

NE2 short Neon Lamp Plain neon lamp, Colon indicator, install plasticspacer underneath. Mounts on Colon sub-board, sleeving around indicator may beuseful to reduce reflections on adjacent nixietubes.

DS3 NE2 short Neon Lamp Plain neon lamp, HV BITE indicator, installplastic spacer underneath.

F1 RXE075 Polyswitch fuse (looks likeyellow disc capacitor)

Radial Leads, larger disc.

F100 RXE030 Polyswitch fuse (looks likeyellow disk)

Radial Leads, smaller disc.

J2 DC power connector Seat firmly to board.J9, J10, J11 20 pin male 0.1” pitch header Can be shrouded or unshrouded, not required

on combined board unless remote displayoperation is intended. Can be top or bottommounted.

L100 Ferrite bead on a lead Can be any style, single or multi-turn bead.L101 100 or 150uH 2A toroid choke.

CTX150-1-52 or sim.Mount elevated as shown. RTV under toanchor the part is useful. Larger value reduceswaste heat.

LED1 T 1 ¾ Green LED Flat side is cathode (short lead), align tosquare PCB pad. Install plastic spacerunderneath.

N1, N2, N3, N4,N5, N6

IN-14 Nixie Tube Flying leads, trim for easier insertion. Removebases if LED back lighting will be used.

R1, R2, R3, R4,R5, R6

22K, ½ W Resistors 5% Axial Leads, CC: red, red, orange, goldElevate above board slightly.

R7 680K, ¼ W Resistor 5% Axial Leads, CC: blue, gray, yellow, goldR8, R9, R10, R11 499K, ¼ W Resistors 1% Axial Leads, CC: yellow, white, white, orange,

brown. Note that the bottom leads of R9, R10are used to attach the colon sub-board, do notcut! Mounts on colon sub-board, note thatearly board art has 100K marked.

R12, R13 33K, ¼ W Resistors 5% Axial Leads, CC: orange, orange, orange, gold.R14, R15, R16 4.7K Ohm, ¼ W Resistors 5% Axial Leads, CC: yellow, violet, red, goldR17 470 Ohm, ¼ W Resistor 5% Axial Leads, CC: yellow, violet, brown, goldR18 10 Ohm 2W Flameproof Resistor 5% Elevate above the board, CC: brown, black,

black, gold. Can be increased if input voltage ishigher than the default 12VDC, used todissipate excess heat from U9.

R100 33K, ¼ W Resistor 5% Axial Leads, CC: orange, orange, orange, gold.R101 1K, ¼ W Resistors 5% Axial Leads, CC: brown, black, red, goldR102 221K, ¼ W Resistor 1% Axial Leads, CC: red, red, brown, orange,

brownR103 Not usedR104 1K Trimpot May be single or multi-turn, face adjustment

out to outer edge.R105 10K, ¼ W Resistor 5% Can also be 1%, Axial Leads, CC: brown,

black, orange, gold (5) or or brown blackblack, red, brown (1%) or 1002F 1%.

R106 470 Ohms ¼ W Resistor 5% Axial leads. CC: yellow, violet, brown, gold


R107 2.2K ¼ W Resistor 5% Axial leads. CC: red, red, red, goldR-Ground 1 Megohm ¼ W Resistor 5% Used to provide a static drain to a metal

cabinet. OptionalQ1, Q2 MPSA42 Transistor Align to case outline on PCB.Q100 IRF820 or sim. MOSFET Caution, static sensitive, handle with care.

Attach to board with provided screw and nut,place head on underside to avoid track short.

Q101 2N2222A or PN2222 Transistor Board accepts either type, note that flat line ison the wrong side on early board artwork,emitter goes to the outside track.

S1, S2, S3 Pushbutton switches Can also be external switches of any kind,SPST, Normally Open.

UP1 Programmed Atmel Microcontroller Install in socket, as last operation to avoidstatic damage. Check alignment.

U1, U2, U3, U4,U5, U6

74141 or K155ID1 Nixie Driver Install in 16 pin sockets, nixie drivers.

U7 Maxim DS32KHZ32.768KHz TCXO, DIP

Optional stabilized TCXO, DIP package

U8 Maxim DS32KHZ32.768KHz TCXO, SMD

Optional stabilized TCXO, SMD package

U9 LM340T5, 7805CT or sim. 5VRegulator

Attach to board with mounting hardware.

U10 LM340T12, 7812CT, or sim. 12VRegulator

Used only if raw input power is higher than12VDC. Optional Jumper input to outputpads if not used.

U100 NE555T, LM555N etc., timer Use 8 pin dip socket underneath.Y1 32.768KHz Crystal, may have the

frequency or a code like R38 on it.Radial Leads. Default timebase.

16 Pin Sockets 6 pieces, under each driver, U1-U68 Pin Socket 1 piece under U10040 Pin Sockets 1 piece, under microprocessor UP1Threaded Spacersand mating screws

5 pieces, mount under the board withprovided screws.

4-40 tapped, can be used to attach the boardto your own case design.

Screws and nuts For U9 and Q100 4-40 or 3mm.Angle brackets &screws

For the provided remote switchassembly

4-40 screws and brackets

Ribbon Wire 4-wire For remote switch assembly. 1 foot. Can be gray or colored.

Solder Water solubleorrosin core solder,as requested. Relevant type isCIRCLED.

63-37 formula, for minimal cold solder joints.


6X-series Remote Display Boards Annotated PARTS LIST:

Mountinghardware

Stand-offs and screws provided forboard attachment

C1, C2, C3, C4,C5, C6

0.1uF/50V or better bypass Capacitor Radial leads, Can be marked .1 or 104, dippedor molded case.

C7 22uF/16VDC or better Radial Leads, OBSERVE POLARITY!Can be dipped tantalum or alum. electrolytic

DS1, DS2 A1A long neon lamp, with sleeve atmiddle to create two lit areas.

Used on 6XIN17 board ONLY.

DS1, DS2, DS3,DS4

NE2 short neon lamp Used on 6XB5092 board ONLY.Mount with plastic spacer underneath

JP1, JP2, JP3 20 pin 0.1” pitch headers Can be shrouded or unshrouded.N1, N2, N3, N4,N5, N6

IN-17 Nixie Tube on 6XIN17 boardonly

Flying leads, trim for easier insertion.

N1, N2, N3, N4,N5, N6

B-5092, 8037, ZM1020, 1022, etc.Nixies on 6XB5092 board only.

Install PC sockets under tubes.

R1, R2, R3, R4,R5, R6

22K, ½ W Resistors 5% Axial Leads, CC: red, red, orange, goldElevate above board slightly. Early artworkmay say 27K.

R6, R7 330K ¼ W Resistors 5% Axial Leads, CC: orange, orange, yellow, goldEarly boards show 150k.Used on 6XIN17 board ONLY.

R6, R7 249K ¼ W Resistors 1% 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 padsprovide the HV and colon connections. Interconnection between the main clock board and remote display is via20 pin ribbon cables (watch out for mis-alignment or reversal end for end), and by flying leads between JP4 onthe display board and J13 on the clock board. To run a remote display from a combined board, you need to runBCD data and a connection from the +170VDC test point (J1), and two wires from the colon outputs. Remove theNixie 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 endare required. Insure the +5VDC ends (red stripe or other marker) are always aligned between boards!


SCHEMATIC: Look at the Schematic of the clock and remote displays before starting work, and be sureyou understand how the clock is designed. The smaller U6DNC-ND version is just a subset of the mainschematic, with the drivers and display tubes deleted. The microprocessor (UP1) (and its crystal clock) do all thetimekeeping and counter control. BCD (Binary coded decimal) data (4 lines) is sent from the microprocessor tothe Nixie driver chips, which can be 74141 or K155ID1 types, which convert the 5V logic to the HV line controlrequired by the Nixie tube. The 7441 can not be used, as it does not support blanking, which is required in manymodes. Other Nixie tubes can be used and hard wired into the board pads. Note that the pads indicate thefunction of the pad, NOT THE PIN NUMBER. A is for Anode, 1-9 and 0 for the specific cathode element, andDP for decimal points. Tubes like the IN-16 are easy substitutes. The remote display boards are essentiallyidentical, 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 isneeded, 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 mosttubes, 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 toavoid problems. The HV level is adjusted by measuring the +170VDC test point (J1) to DC common (J5), andadjusting trimpot R104. If no tubes are present, the voltage can go quite high (over +250VDC), so care must beused to set it to +170VDC as a starting value. “HV present” is indicated by neon lamp DS3 being lit. +5VDC forthe 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 keep-alive voltage must be present for any CPU operation, and it prevents time loss during momentary primary powerinterruptions.

JUMPERS/OPTIONS: Jumpers at U10, D1 and D5 are installed (and D2, D4 delted) when the primarypower is a nominal 12VDC, these parts are required if primary power is AC or if it is over 12V average. C18 isrequired 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 isalso supplied (LED1) which warns when the logic supply is present. A crowbar Zener is across the 5V powersupply to clamp any excess voltage applied by mistake, and as a static shunt. If this part shorts, or is installedbackwards, the 5V bus will never rise above about 0.7VDC, and the FI polyswitch fuse will open (self-resettingwhen 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 glassfuse. Primary AC line protection is still by a one-shot glass fuse for fire safety within the wall wart. Polyswitchesare conductive as long as the current is at or below their specified holding value, but go essentially open circuitwhen the current is too high. They are reset back to proper conducting operation by removing the short, and/ orresetting the primary power. The 5VDC light will go out when the primary Polyswitch opens. This technique isused because many assembly problems may create a “short”, and this would be very inconvenient for you if youhad only one glass fuse available. In addition, R18 is a fusible resistor, in series with the 5VDC regulator, it limitscurrent to the regulator if a problem is present on the 5VDC rail, if it gets hot, remove power, and search for theproblems.

CABLES: Connection to the setting switch assembly is via a short length of ribbon cable, which can simplybe soldered to each end. The remote displays are connected by 3 individual 20 pin ribbon cables, plus at least 3additional 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 theconnectors are not plugged in offset, or reversed end-for end, they will work. It is also possible to solder the wires,if preferred.


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 optionalon the combined board, and are required on the split version. They can be installed on the top or bottomside, it does not affect operation or cable design. The DIP version of the temperature compensated oscillatorat 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 correctvalue 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, D4and D5 is NOT normally required (unless an AC power supply is used), and jumpers are normallyinstalled at D1 and D5. Note that D6 is a schottky rectifier, 1N5817 or similar, and D100 is a fast highvoltage 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 behard to find later, but can cause serious failure.


4. Insert and solder the IC sockets, note that one end is notched, to mark the similarly notched/marked endof the ICs themselves (pin 1 end). Be sure the sockets are fully tight to the board (insert, then bend overthe corner pins to make it grip the board). The UP1 microprocessor socket has gold machined pins. Ablue-green ZIF socket is shown in some pictures, but that was used only during prototyping, the normalsocket 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 asshown or brown dipped radial parts, marked 104. C13 can be either 0.1uF or 0.01uF, not critical, and isused 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 sidemarked 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 allbe installed correct, double check the polarity of every part. C102 and C103 are especially critical, seethe 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 theboard with the provided screw and nut, the HEAD should be on the board BOTTOM side, to avoid a shortto the adjacent track. Solder and trim the leads, and attach the toroid choke L101 as shown above, theleads just reach to the holes. A dab of glue or RTV to anchor the choke is useful. Install the trimpot atlocation 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 canlift one lead of the polyswitch and insert an ammeter to monitor the HV inverter current consumption ifyou have a problem in this area.


10. Insert and solder the transistors Q1 and Q2 (MPSA42/44 high voltage colon drivers), watch for the correctorientation, 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 asshown below, this part will be correctly pre-installed on initial boards. The emitter goes to the outsidetrack.

11. Install U9, the +5V Voltage Regulator, typically an LM340T5, or 7805T, etc. attach the flange to the boardwith a screw and nut, and solder the 3 leads to the board. Double check the large polarized capacitororientations in the power supply against the picture below, and note that C13 and C18 are optional, andnot normally required:

12. Install and solder the DC power jack at location J2, unless you have a different way of connecting powerin your system. The wall wart plugs directly to the jack, a clearance hole at the rear of the case (withouttouching the jack in any way) is required. Note R18 above, it is a 10 Ohm, 2W flameproof part, or otherlarger parts could be used if the supply voltage is higher than normal.


13. Install and solder the crystal, Y1, next to the microprocessor. It looks like a tiny metal cylinder, with twoleads out one end. It may have the frequency or a code like R38 on it. Either Y1, or U7 or U8 arerequired for the clock to run, or an external timing signal attached to J8.

One crystal/osc. required

14. Install and solder the 5V indicator Led at LED1 using an elevator spacer, note that the LED has a flat onone side of the plastic case, this is the cathode (it’s also the shorter lead), and should go to the squarepad 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 HighVoltage 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 goingthrough them), to improve the reliability of the board. Install the headers at J9, J10 and J11 if a remotedisplay 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 applypower. The green LEDs should both light (5V DC power and HV converter Power), and a voltmeter testat 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 adjustR104 for +170VDC at J1. If any of these steps is not possible, stop and examine the circuit inquestion. You cannot proceed until all of these power tests are satisfactory.

Examine the IN-14 Nixies, they have a bottom spacer pad, andlong leads. Normally, they are mounted flush with the board, andthe spacer pad provides a shock isolating cushion. Wheninstalling them into the board, you need to be sure they arevertical in all axes (not tilted), and the same height as the othertubes, for a clean looking display.

When the tubes are correctly facing forward, the one internal leadwith white insulation will be in the pad marked A at the rear.Examine the tubes and the board, and be sure you understandthe correct orientation of the tube, it has no gap between pins toaid this, you have to align it for the correct location. The digitsmust be forward, and the white insulated pin must be in pad A.

If you intend to use the LED back lighting board under thetubes, you must remove the white insulator before solderingthe tubes, and use a spacer to raise them all ¼” above theboard.


18. You can either clip the leads short (about 1/2”), and straighten them for insertion into the board, and feedthe leads into the board one at a time. This is a slow and tedious operation, so be patient, and avoidrushing, as a mistake here can be very costly in terms of time and money. It is helpful to tack each tubeat one or two pins with the soldering iron before soldering all pins, so that you can be sure all tubes are ingood visual alignment. Use a towel or something soft to cradle the board while installing the tubes, toavoid 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 leakagewhen operating, and unwanted digit illumination.

20. Assemble the 3 pushbutton switches to the remote switch setting board, be sure they are all even andstraight. Attach the two right angle support brackets (they are not symmetrical) to the board so that thefront holes line up with the switches. Add the legend overlay and mount it with two screws. This willeventually be mounted to your case. Attach the 4 wire ribbon cable to the pads GRSA, this will beattached to the same pads at area W1 on the main board (G to GND, R to RESET, S to SET, A toADVANCE).

21. Assemble the neon lamps (spacers can be used under the lamps to move them forward) and resistors onthe two small colon boards. Note that the bottom resistor lead is used to anchor the board, along with anadded front jumper wire, to the main clock board. There is no difference between boards, either one canbe in either position. Adjust the jumper/lead height to get the exact vertical colon alignment you wantbefore soldering. You may want sleeving around the lamps to reduce side reflections on the nixie tubes.


22. Insert the driver ICs into the sockets, watch for correct alignment and that no leads are bent underthe 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 thefont), as shown below:

Pin 1 (notch) Orientation

23. Discharge yourself to any large metal object, and take the microprocessor from its protective anti-staticbag, and carefully insert it into the socket, watch that the orientation is correct, and that no leads are bentunder the chip.

24. At this point, assembly is complete, and you are ready to connect the power supply and begin testing andset up of the clock. If you have the split boards, you will also need to connect the units together as per thecircuit 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 (thecombined board will be reversed, don’t worry). It should then begin counting seconds. The clock goesthrough the digit cycle only on initial power up, not once the supercap is charged, as it then displays thestored time. To force the re-cycle, unplug power, and discharge the supercap with a jumper lead, andthen re-attach power. For the combined cock, you will need to reverse the display sequence, that isOPTION 52 in the Neonixie software menu, see the attached command set for the clock softwarefor full instructions. In the menu, you can control virtually every aspect of the clock, and it willstore those settings for future operation. The remote switch board must be attached and workingto access those functions.

Cases:

Any case that appeals to you is satisfactory as long as it prevents accidental shock contact with the HV powersupply, and prevents the nixie tubes from being broken. The split board set allows the most flexibility inpackaging, 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 andonly Q100 and L101 get a bit warm during operation, and U9 less so. Case ventilation is useful to avoid thermalbuild up that may skew timebase operation, especially with the crystal.


A Word About Grounding:

The boards do not make any connection to ground (chassis) via the mounting holes normally. This is to avoidany problem in case your power supply happens to make contact with ground for some reason, such as using anAC 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 settingor other handling can cause logic upsets and other problems. For this reason, both the switch sub-assembly andmain board allow for a jumper to a physical chassis ground connection via the mounting stand-offs. The resistorat R-GROUND is very useful, and works even if you have some kind of power supply return path. The connectionat the switch board (ground jumper) is a hard ground, and your power supply must not be incorrectly returned tothe chassis for it to work.

Provided Ground Connections

You can use stand-offs (conductive) to heat sink U10 and U9 to your metal chassis if you wish, but DO NOTground U100 for any reason, or serious damage will result.

Clock Board Connections:

Origin Method DestinationJ1 (+170VDC) Test probe Meter, +170VDC test pointJ2 (Power In) Power supply connector from wall

wartTo 12VDC input power

J3 (ACIN2) Wire (optional) AC Power InputJ4 (ACIN1) Wire (optional) AC Power InputJ5 (DC Common) Test Probe Meter common (ground)J6 (+DCRAW) Test Probe Meter, Internal 12V bus monitorJ7 (+5VDC) Test Probe Meter, +5VDC test pointJ8 (EXT CLOCK) Wire (optional) Remote 32.768KHZ timebaseJ9 (Hours) 20-wire Ribbon cable Hours BCD Data to remote display

Goes to JP3 on remote display.J10 (Minutes) 20-wire Ribbon cable Minutes BCD Data to remote display

Goes to JP2 on remote display.J11 (Seconds) 20-wire Ribbon cable Seconds BCD Data to remote display

Goes to JP1 on remote display.J12 (+Vcc BACKUP) Test Probe Meter, +4.5VDC keep-alive test point

W1 (Remote Switches) 4-wire ribbon cable, soldered To remote setting switch board


Nixie Reference Data (bottom views):

IN14: IN16:

IN17:

B5092, 8037, 8421 and Similar:

Electrolytic Orientation : Tantalum Capacitor Orientation:

Negative is DOWN (Stripe) Negative Positive


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 toinspect the board, it can really help.

Power:Everything flows from the power supply, so be sure you have correct +5VDC and +170VDC operation. If theseare 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 anythingelse to work. A dead short can cause F1 to open, disconnect power and re-connect to reset F1. The commonpoint 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 thosesections. If D3 is installed backwards, 12VDC will be sent to the 5V circuits, hopefully clamped by D7 to preventtotal destruction of your logic parts. If this has occurred, reverse D3 (check to be sure it is not shorted), and checkD7 to be sure it is not shorted. F1 will open under catastrophic conditions, BUT it cannot prevetn all possibledamage 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 positionD100, 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 voltageis present (check J12). A reversed diode at D6 or a reversed supercap at C11 can prevent this voltage frombeing 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), badsoldering 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 theheaders to test a specific nixie and driver. Note that headers are labeled for the remote display, and are reversedin sequence for the combined board.

If your clock displays backwards (left to right), (combined board), you have to select the reversed option in theneonixie menu, item 52. See the option lists for setting that function. The remote boards use the defaultconnections 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 reversedat one end. Note that a hard ground to chassis jumper is possible at the switch assembly, this can causeproblems 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 isgood! 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!

U6DNC Nixie Clock Kits URL - Sphere · 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

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