Pvelectronics Halo Chroma Configuration guide

Nixie Tube Clock ‘Halo Chroma’
Issue 1 (1 April 2021)
www.pvelectronics.co.uk
- 1 -
Assembly Instructions
And
User Guide
Nixie Clock Type
‘Halo Chroma’
For Parts Bag Serial
Numbers from 000 onwards

Nixie Tube Clock ‘Halo Chroma’
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www.pvelectronics.co.uk
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REVISION HISTORY
Issue
Number
Date Reason for Issue
Issue 1 1 April 2021 New document

Nixie Tube Clock ‘Halo Chroma’
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1. INTRODUCTION
1.1 Halo Chroma - Features
 Hours, Minutes and Seconds display
 Drives Z560M, Z5600M, GN-4, ZM1022 and many other compatible tubes
 Uses a Quartz Crystal Oscillator as the timebase
 12 or 24 hour modes
 Programmable leading zero blanking
 Date display in either DD.MM.YY or MM.DD.YY or YY.MM.DD format
 Programmable date display each minute
 Scrolling display of date or standard display
 Alarm, with programmable snooze period
 Optional GPS / WiFi / XTERNA synchronisation with status indicator LED
 Dedicated DST button to switch between DST and standard time
 Supercapacitor backup. Keeps time during short power outages
 Simple time setting using two buttons
 Configurable for leading zero blanking
 Double dot colon neon lamps
 11 colon neon modes including AM / PM indication (top / bottom or left /
right), railroad (slow or fast) etc.
 Seconds can be reset to zero to precisely the set time
 Programmable night mode - blanked or dimmed display to save tubes or
prevent sleep disturbance
 Rear Indicator LEDs dim at night to prevent sleep disturbance
 Weekday aware ‘Master Blank’ function to turn off tubes and LEDs on
weekends or during working hours
 Separate modes for colon neons during night mode
 Standard, fading, or crossfading with scrollback display modes
 ‘Slot Machine’ Cathode poisoning prevention routine
 Programmable RGB tube lighting – select your favourite colour palette
 729 colours possible. Have a different colour or your choosing every
hour, or autochanging colours
 Not AC frequency dependent – works in all countries
 Supports output Sync Pulse for our DekaDuo Dekatron Driver Board
 All user preferences stored to non-volatile memory
 Additional wireless functions if XTERNA module used:
- Display of outdoor temperature in Celsius or Fahrenheit. Configurable.
- Min / Max temperature in last 24 hours
- Wireless, Auto Sync of time from GPS with auxilliary TCXO
- GPS Sync time, and time since last GPS Fix
- Voltage of XTERNA module battery

Nixie Tube Clock ‘Halo Chroma’
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1.2 Tubes Supported
There are many types of tube this kit will drive – all have the same
pinout. The commonest types are as follows:
Z560M
Z5600M
GN-4
ZM1022
ZM1020
B-5092
Digit height is generally 15.5mm for all these tubes. A typical tube
is shown below:

Nixie Tube Clock ‘Halo Chroma’
Issue 1 (1 April 2021)
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1.3 SAFETY
DANGER: The clock pcb includes a switched-mode voltage booster
circuit. This generates nominally 170 Volts DC. Assembly may only be
undertaken by individuals who are suitably qualified and experienced in
electronics assembly, and are familiar with safe procedures for working
with high voltages. If in doubt, refer to a suitably qualified engineer
before proceeding.
The voltages generated by this circuit can give a potentially
LETHAL ELECTRIC SHOCK.
DISCLAIMER: This product is supplied as a kit of parts, intended only for
suitably qualified electronic engineers, who are suitably qualified and
experienced in electronics assembly, and are familiar with safe
procedures for working with high voltages. The supplier, his agents or
associates accept no liability for any damage, injury or death arising from
the use of this kit of parts.
This is not a finished product, and the person assembling the kit is
responsible for ensuring that the finished product complies with any
applicable local regulations governing electrical equipment, eg. UL, CE,
VDE.

Nixie Tube Clock ‘Halo Chroma’
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2. TOOLS AND EQUIPMENT REQUIRED
2.1 Tools required to assemble the PCB.
The following tools will be required to assemble the PCB:
- Soldering iron (25W fixed temperature recommended) with a small tip
(1-2 mm).
- Wire cutters to trim the excess component leads after soldering.
(TIP: A small pair of nail clippers works very well for this function).
- Multimeter for voltage tests and for identifying the resistors.
- A small hot air gun will be needed to shrink the heat shrink tubing
over the neon lamp wires.
2.2 Materials you will need.
Solder – lead / tin solder is highly recommended.
USE LEAD/ TIN SOLDER!
Lead free solder, as now required to be used in commercial products in
Europe, has a much higher melting point and can be very hard to work
with.
Desoldering wick (braid) can be useful if you accidentally create solder
bridges between adjacent solder joints.
2.3 Other items you will need.
The clock kit does not include a power adapter.
The following type of adapter should be obtained and used with the kit:
Output 12V DC regulated, minimum power output capability of 500mA
Output plug: 2.1mm pin, centre positive.
A suitable adapter is shown below:

Nixie Tube Clock ‘Halo Chroma’
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3. LIST OF COMPONENTS
3.1 Table of Components
Circuit Designation Part Description
Resistors
R1, R2 4.7 KΩ, ¼ Watt
R3, R4 390 KΩ, ¼ Watt
R5 300 KΩ, ¼ Watt
R6 - R11 270 Ω, ¼ Watt
R12 4.7 KΩ, ¼ Watt
R13 – R15 1 KΩ, ¼ Watt
R16 – R21 4.7 KΩ, ¼ Watt
R22 – R25 15 KΩ, ¼ Watt
Capacitors
C1, C2, C4 220uF Electrolytic
C3 1uF, 250V,
C5 15pF Ceramic
C6 33pF Ceramic
C7 100nF Ceramic
C8 0.22F
C9 100nF Ceramic
Transistors
Q1 IRFD220 MOSFET
Q2 – Q4 EL817 Optocoupler
Q5 – Q9 MPSA42
Diodes
D1 – D3 1N5819
D4 1N4148
D5 UF4004
D6, D8 5mm Yellow LED
D7 5mm Green LED
RGB1 – RGB6 APA106 RGB LED
Integrated Circuits
IC1 LM2576 5V voltage regulator SMD
IC2 PIC16F1938 8-bit microcontroller
IC3 HV5812
Miscellaneous
L1, L2 100uH inductor
AM1, AM2, PM1, PM2 4mm wire ended neon lamp
ALARM, SET, ADJ, DST Vertical miniature push button
IC2 Socket 28 Way narrow IC socket for IC2
IC3 Socket 28 Way PLCC Socket
J1 2.1mm Vertical power socket
SYNC Vertical 3.5mm jack socket
LS1 Piezo sounder
FUSE 500mA fuse
Insulation 25 cm Clear insulation for neons
X1 32.768KHz watch crystal
Tube Sockets Harwin 1mm sockets
Sockets for EL817’s 2 X 6 way SIL socket strips
DEKA 3 Way 0.1” header

Nixie Tube Clock ‘Halo Chroma’
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3.2 Parts list / Packing Sheet - Component Bag
Part Description Quantity
Resistors
270 Ω, ¼ Watt 6
1 KΩ, ¼ Watt 3
4.7 KΩ, ¼ Watt 9
15 KΩ, ¼ Watt 4
300 KΩ, ¼ Watt 1
390 KΩ, ¼ Watt 2
Capacitors
15pF, Ceramic 1
33pF, Ceramic 1
100nF, Ceramic 2
1uF, 250V, Electrolytic 1
220uF, 16-25V, Electrolytic 3
0.22F 1
Transistors
IRFD220 MOSFET 1
MPSA42 5
EL817 Optocoupler 3
Diodes
1N5819 3
UF4004 fast recovery diode 1
1N4148 1
5mm Green LED 1
5mm Yellow LED 2
APA106 RGB LED 6
Integrated Circuits
LM2576 5V voltage regulator SMD 1
PIC16F1938 8-bit microcontroller 1
HV5812 1
Miscellaneous
100uH inductor 2
4mm wire ended neon lamp 4
Miniature vertical push button 4
28 way narrow IC Socket for IC2 1
28 Way PLCC Socket 1
2.1mm Vertical power socket 1
Vertical 3.5mm jack socket 1
Piezo sounder 1
500mA fuse 1
25cm Clear insulation for neons 1
32.768KHz watch crystal 1
10 Way 0.1” Female socket strip 1
2 X 6 way SIL socket strips 1
1mm Harwin Socket 66
3 Way 0.1” header 1
Plexi Tool for bending the RGB LEDs 1
We recommend to check against the list above, to ensure all parts
are present before commencing assembly.

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The resistors used in the kit are 1% tolerance metal film. They are
marked with 4 coloured bands to identify the value. However it is
sometimes unclear in which direction the bands should be read.
Therefore, we recommend that the resistors be identified with a
multimeter.
Please note the fuse will look like the picture below. It can easily be
confused for a capacitor. It is a self-resetting fuse.
The 15pF and 33pF capacitors will be marked 15 and 33
respectively. The 100nF capacitors will be marked 104.
Q1 (IRFD220) is in a very similar package to Q2 – Q4 (EL817). You
can tell the difference, in addition to the part marking by looking at
the pins. Q1 has two pins that are actually joined at the resin body.
Q2 – Q4 have 4 separate pins.
Inductors L1 and L2 may be one of three types:

Nixie Tube Clock ‘Halo Chroma’
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4. ASSEMBLY OF THE PCB
4.1 1mm Sockets For Nixie Tubes
There are 66 individual sockets that need to be placed. Note that
there are 2 holes per tube with NO SOCKET.
Be sure to insert the sockets from the front side of the PCB. This is
the side with substantially more white component markings on it.
Insert and solder all the sockets for each tube at a time, before
moving to the next tube location. Be sure to insert the sockets
FROM the tube side of the PCB – the side with the tube markings.
After inserting the sockets, the best way to hold all the sockets in
place whilst soldering them is to insert a tube.

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Then flip over the PCB and solder the 11 sockets in place, then
remove the tube.
Repeat this for all six tube locations.
4.2 Low Voltage Power Components:
J1, FUSE
D1-D3 (1N5819)
D4 (1N4148)
IC1 (LM2576)
L1 (100uH Inductor)
C1, C2 (220uF)
Start by installing D1-D4. The diodes are polarized – the band on
the part must match the band marked on the white PCB marking.

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IC1 is a Surface Mount part, but it is large and easy to solder. Start
by wetting one pad with solder. Then place the part in position and
heat the lead so the solder below it melts and anchors the part.
The four other leads can then be soldered. Do not solder the
heatsink tab.
The leads of C1, C2 and the inductor L1 need to be bent as shown
below. The inductor is not polarized, but C1 and C2 are polarized
so note the positon of the pale stripe when bending the leads. This
will ensure the pale stripe matches up with the cross hatched
marking on the PCB.

Nixie Tube Clock ‘Halo Chroma’
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Then solder these three parts noting that the inductor L1 is placed
on the opposite side of the PCB to the capacitors C1 and C2.
Finally solder the fuse and connector J1 which is soldered on the
opposite side of the PCB to the fuse.

Nixie Tube Clock ‘Halo Chroma’
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4.3 Testing Low Voltage Power Supply.
Identify the test GND, 5V and HV test points as shown below.
Plug in the power supply, and then test using a DC voltmeter:
Touch the black probe on the GND test point and the red probe on
the 5V test point. The voltage should measure between 5.4 and 5.8
Volts. If not, disconnect power and check your work. Do not
proceed with the assembly until the error is corrected. Once the
test is completed, disconnect the power.
IF YOU CHOOSE TO PROCEED BEYOND THIS POINT
WITHOUT GETTING THE CORRECT VOLTAGE, WE WILL NOT
BE ABLE TO OFFER SUPPORT
4.4 High Voltage Generator components.
Socket for IC2
R1, R2 (4.7 KΩ)
R3, R4 (390 KΩ)
R5 (300 KΩ)
C3 (1uF)
C4 (220uF)
Q1 (IRFD220)
L2 (100uH Inductor)
D5 (UF4004)
Solder the 5 resistors and the diode first as they are lower profile –
its easier to solder the top pad rather than the bottom pad. This
prevents the component falling out as you try to solder an inverted
PCB! L2, C3 and C4 need to have their leads bent, and for C3 and
C4 the polarity is critical, so do as you did with C1 and C2 to
ensure the pale strip on the part matches the cross hatching on the
PCB.

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Also the MOSFET needs to be placed with the two joined pins at the
position shown on the PCB by a thick white line.
Take care that the notched end of the IC socket is at the end
shown. However, if you find you soldered it with the wrong
orientation, do not try to remove it. It is perfectly fine with the
notch at the wrong end, just be sure to place the IC in the socket
with the IC’s notch in the correct position.

Nixie Tube Clock ‘Halo Chroma’
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4.5 High Voltage Generator Test.
- Refer to the warnings on page 5
- Insert IC2 into its socket. Orient the notch on the IC with the
notch on the IC socket and the PCB marking.
- Power up the PCB, and using the GND and HV test points,
measure the high voltage generated using a voltmeter on DC
setting. It should be between 164 and 176 Volts. If this is in order,
disconnect the power supply. If you do not get this voltage, do not
proceed.
IF YOU CHOOSE TO PROCEED BEYOND THIS POINT
WITHOUT GETTING THE CORRECT VOLTAGE, WE WILL NOT
BE ABLE TO OFFER SUPPORT
4.6 C5 (15pF)
C6 (33pF)
X1 (32.768KHz Crystal)
C7 (100nF but marked ‘104’)
(C7 may be a different colour)

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4.7 R13, R14, R15 (1 KΩ)
4.8 Q2, Q3, Q4 (EL817)
SIL Socket Strip
You will either receive 2 X 6 Way sockets, or a 12 way IC socket.
Assemble the parts as shown below, paying attention to the
orientation of the dot on the body of the parts.

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4.9 R16, R17, R18, R19, R20, R21 (4.7 KΩ)
These are the anode resistors.
4.10 Socket for IC3 and IC3
Align the chamfer on one corner of the socket with the marking on
the PCB. Be careful not to force in the socket if all pins are not
aligned. Ensure all pins are fully pushed through the holes before
soldering in place. If you find you soldered it in the wrong
orientation, don’t try to remove it. Contact us for an easy remedy.
Now insert IC3, with the dot and chamfered edge aligned as shown
by the arrow in the picture below.

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5. FIRST TUBE TEST
It is now time to check that all tubes are working correctly.
5.1 Insert the Tubes
Insert six compatible tubes into the sockets. You can look into the
glass body and see the orientation of the digits as a guide to
getting the orientation of the tube correct.
5.2 First Tube Test
Now power up. After a short delay, the tubes should light and all
start counting from 0 to 9 and repeat. Please note this is a count
UP, not a count DOWN. If you contact us with a support issue at
this stage, please be clear about the count up. If you refer to a
count down, it will be very confusing and slow down your support
query!
If you do not get this count up, or have missing or overlapping
digits, stop and check your work. Try swapping tubes around to
see if the problem is with the tube, or the location. Please make
these basic tests before contacting us for help and have the results
to hand.
IF YOU CHOOSE TO PROCEED BEYOND THIS POINT
WITHOUT GETTING THE CORRECT TUBE CYCLING, WE WILL
NOT BE ABLE TO OFFER SUPPORT

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6. PCB ASSEMBLY CONTINUED
6.1 R6, R7, R8, R9, R10, R11 (270 Ω)
6.2 Q5 – Q9 (MPSA42)
R12 (4.7 KΩ)
SYNC (Vertical Jack Socket)
LS1 (Piezo Buzzer)
C8 (0.22F)
The jack socket, piezo buzzer and C8 are mounted on the back of
the PCB. Ensure the arrows on C8 are aligned with the
corresponding arrows on the PCB
6.3 C9 (100nF)
Note this part is likely to be marked ‘104’.
6.4 D7 (5mm Green LED)
D6, D8 (5mm Yellow LED)
SET, ADJ, ALARM, DST (Push switches)
All these components are mounted on the back of the PCB. For the
four switches, you only need to actually solder the two pads of
each switch closest to the PCB edge. The other two pins / pads are
not used. It makes it easier in case you ever need to change a
switch.
The LEDs are polarized. The longer lead is the positive anode, and
goes into the hole that is marked with a + sign.
6.5 R22 – R25 (15 KΩ)