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Items relevant to "Mains Power-Up Sequencer, part two":
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Compact Frequency Divider
Project by Nicholas Vinen
This small board converts a standard 10MHz
frequency reference (eg, from an oscilloscope)
to 1MHz and 1Hz square wave signals. The latter
can emulate the 1PPS output of a GPS receiver
and has options for a 10% or 50% duty cycle.
Build your own compact
Frequency Divider
10MHz – 1MHz | 10MHz – 1Hz
T
his straightforward circuit
accurately divides a 10MHz
signal to 1Hz with extremely
low jitter. It has various applications, such as testing clocks and other
devices that are time-locked to GPS
signals.
It could also be used to drive several clocks from a single accurate time
source or to derive a very accurate
1Hz signal from a low-cost 10MHz
temperature-c ompensated crystal
oscillator (TXCO).
The divider uses just four logic
ICs, including the somewhat unusual
74HC4059, plus an ultra-high-speed
comparator and a buffer for driving
the outputs. It can be powered at 5V
DC from a USB supply or 6.6-12V DC,
drawing only about 10mA. It has supply reverse polarity protection and
input overload protection and won’t
generate an output unless it’s being
actively fed a signal.
A jumper selects between the
10% and 50% duty cycle options for
the 1Hz output. The output jitter is
extremely low as long as the input
signal is relatively clean. Many pieces
of test equipment will have a suitable
10MHz output, or you could use one
of our GPS-Disciplined Oscillators:
• GPS-Disciplined Oscillator (May
2024)
• GPS-synched Frequency Reference (October and November 2019)
• GPS-based Frequency Reference
(April & May 2009)
Circuit details
Its circuit is shown in Fig.1. We have
tried to keep it simple and inexpensive
without sacrificing performance. The
10MHz signal is fed into SMA connector CON1 and goes into the first stage,
based on ultra-high-speed comparator
IC6 (TLV3501).
The TLV3501 is an interesting
device as it runs from 2.7 to 5.5V, drawing just 3.2mA and yet has extremely
low input bias currents at ±2pA (typical), a low input offset voltage of ±1mV
(typical) and very high-speed operation with a maximum toggle frequency
of 80MHz. That makes it suitable for
many applications.
Here, its job is to convert what might
be a relatively low-level, sinusoidal
input signal into a 5V peak-to-peak
square wave. That means the circuit
is not too sensitive about what drives
it, as long as it is a 10MHz waveform
of at least 10mV RMS or 35mV peakto-peak; it will most likely be a sine
or square wave.
The circuit is designed with 75W
impedances in mind, although you
could change that if necessary (eg,
using 49.9W or 51W resistors instead
of 75W). So the input is terminated
with a 75W resistor, then coupled to
comparator IC6 by a 1nF DC-blocking
capacitor and 220W series resistor.
Dual schottky diode D1 protects
IC6 from over-voltage or having a signal applied while the circuit is powered down by clamping the input signal to within 0.3V of the supply rails.
Frequency Divider Features & Specifications
» Divides the nominally 10MHz input frequency by 10 (to 1MHz) and 107 (to 1Hz)
» 10% or 50% duty cycle option for 1Hz output (5V peak-to-peak unloaded)
» Operating input signal level: 10mV to 3.2V RMS (28mV to 9V peak-to-peak)
» Recommended input signal: 35mV to 2V RMS (100mV to 5.6V peak-to-peak)
» Jitter: estimated at 0.1ns with a clean clock source (see Scope 1)
» Propagation delay: approximately 100ns
» High noise immunity with 23.5mV built-in hysteresis
» Outputs are in phase with inputs
» No output signals if the input is not driven
» SMA connectors for input and outputs
» Choice of 50Ω or 75Ω input/output impedances
» Power supply: 5-12V DC <at> 10mA
» Power connectors: USB Type-C, 2.1mm/2.5mm inner diameter barrel plug,
(polarised) pin header
» 3mm mounting holes: 4 (the board can be made smaller by cutting them off)
Practical Electronics | March | 2025
The prototype board is very
similar to the final version; it just lacks
the power LED and used a Type-B mini
USB socket instead of the now more
standard Type-C.
39
Constructional Project
Scope 1: the yellow waveform is the 1Hz output (reduced in
amplitude due to a lower than normal supply voltage and
50W termination) while the blue waveform is the 10MHz
reference signal from the oscilloscope. The grey areas
around them show the previous 50 or so traces, indicating
extremely low variation in timing between them (ie, low
jitter). The output edge seems to come first because the
propagation delay is just under the input signal period
(100ns); it was triggered by the previous edge.
The 220W resistor primarily exists to
limit the current through these diodes,
protecting them and the rest of the circuit from excessive ‘bus pumping’ of
the 5V rail.
As the signal is AC-coupled to IC6,
it is DC-biased to half of the 5V supply
using a pair of 10kW resistors and a 47kW
bias resistor. The 100nF capacitor prevents supply ripple from coupling back
into the signal, which could cause jitter.
A 10MW resistor from output pin 6
of IC6 back to its non-inverting input,
pin 3, provides around 23.5mV of hysteresis for noise rejection. This forms
a voltage divider with the 47kW bias
resistor for pin 3. With around 2.5V
across the hysteresis resistor (regardless of whether IC6’s output is at 5V or
0V), 2.5μV flows through it and subsequently the 47kW resistor, causing an
offset of around 11.75mV.
That offset switches polarity as
IC6’s output switches, meaning that
any noise on the input signal would
have to exceed 23.5mV to cause an
unwanted edge at IC6’s output. It also
means that there needs to be at least a
23.5mV peak-to-peak signal applied to
IC6 before its output will start to toggle. Thus, it won’t oscillate without a
signal at CON1.
With the 75W termination resistor,
plus the low-pass filter formed by the
220W resistor and IC6’s input capacitance (plus that of both diodes in
40
Scope 2: to check the frequency ratio was correct, we
captured the unit’s output on the scope for two seconds
and then measured the time between edges. Here three of
the captured edges are overlaid, in yellow (-500ms), red
(0ms) and green (+500ms). The yellow and green traces
overlap, indicating they are exactly one second apart as
per the scope’s timebase (and hence 10MHz reference
oscillator). As we captured two full seconds of data, the
time resolution is more coarse than in Scope 1.
D1), the minimum signal the circuit
will respond to is about 30mV peakto-peak at CON1. However, a higher
level is recommended to ensure jitterfree operation. 30mV at CON1 implies
a higher voltage at the signal source,
probably closer to 60mV peak-to-peak.
Frequency divider
Now that we have a clean 10MHz
square wave signal from IC6, it’s
fed to the first divider, IC1. This is a
74HC4017 Johnson decade counter, a
lower-voltage, higher-speed version of
the good old 4017 counter IC.
These are inexpensive, run from
2-6V, operate at up to 77MHz with a
5V supply and provide ten 10% duty
cycle outputs with different phase
angles, plus a single 50% duty cycle
output that’s phase-aligned with the
input (and Q0 output).
For IC1, we feed the 10MHz signal
into the pin 14 clock input and get a nice
1MHz square wave from the Q5-Q9 output. The MR (master reset) line is tied
low for constant operation, while the
inverting clock input at pin 13 is also
tied low as we are using the non-inverting clock input. The ten phase outputs,
Q0-Q9, are not used in this case.
The 1MHz output from pin 12 is fed
to two places: firstly, to three of the six
buffers in IC5 connected in parallel,
then to the 1MHz SMA output (CON2)
via a 75W impedance-matching resistor.
The MC74VHCT50A is similar to a
74HC04 hex inverter IC except that it
does not invert the signals but merely
buffers them. That keeps the outputs in
phase with the 10MHz input.
Secondly, the pin 12 1MHz output
of IC1 goes to another 74HC4017 counter, IC2, configured identically to IC1.
It produces a 100kHz square wave at
its pin 12 output, which is fed to the
clock (CP) input, pin 1, of IC3.
This is the ‘main event’, configured to divide its input frequency
by a factor of 10,000. It is a larger IC
than the others, with 24 pins rather
than 16, and somewhat more expensive (but still pretty reasonable). It
takes up less space than four more
74HC4017s and has a much lower
propagation delay.
It can be configured for thousands
of different frequency division ratios
in various ways based on the logic
states of its KA-KC and J1-J16 pins. The
accompanying panel explains how
this particular configuration achieves
the 10,000:1 division ratio.
We could have added a microcontroller to this board, driving all those
pins, and provided a few different
ratios. However, we decided it was
better to keep this simple and avoid
programming any chips. Still, we will
present a more complex programmable design that includes a microcontroller in an upcoming issue.
Practical Electronics | March | 2025
Compact Frequency Divider
Fig.1: the circuit uses three divideby-ten ICs (74HC4017) and one
divide-by-10,000 IC (74HC4059)
to reduce the 10MHz input at
CON1 to 1Hz at CON3. High-speed
comparator IC6 converts whatever
waveform is fed in to a 5V peak-topeak square wave for driving IC1.
IC3 has an output latch that we do
not use, so the latch enable (LE) input,
pin 2, is tied to ground. The 10Hz signal appears at pin 23 (Q). Note, though,
that this pin will only be high for one
input pulse, and with a 100kHz input,
the output pulses are 10μs wide. That is
why we divided the 10MHz signal by a
Practical Electronics | March | 2025
factor of 100 first; otherwise, the output
pulses would be a mere 100ns wide.
To make this short pulse useful, we
feed it to the final counter, IC4, another
74HC4017 configured much like the
others. It performs the final division to
get a 1Hz signal and converts the short
pulses into a 50% duty cycle square
wave at its pin 12 output.
We feed that, plus the similar but
shorter 10% duty cycle pulse from
output Q0, to a three-way pin header.
That allows you to select the desired
duty cycle using a jumper shunt. The
resulting signal is fed to another triple
parallel buffer (IC5d-IC5f) and then the
41
Constructional Project
final SMA output, CON3, via another
75W impedance-matching resistor.
The 10% duty cycle output more
closely simulates a GPS 1PPS output,
while the 50% duty cycle signal is nice
and symmetrical for driving something
like a clock.
Power supply
There are three power supply
inputs. The USB Type C connector
(CON4) is the simplest as it feeds the
USB 5V directly into the circuit. However, note that its ground connection
goes via the internal switch in barrel
socket CON5. This way, if you plug
both in simultaneously, you won’t be
feeding power into the device connected to the USB socket.
Unlike USB Type-B sockets, the
Type-C socket needs two 5.1kW pulldown resistors connected to signal
the power source to deliver 5V. You
can leave those resistors off the board
if you aren’t fitting the Type-C socket.
This particular socket only has the six
pins needed for USB power delivery,
without the data signals.
By the way, we’re switching from
Type-B to Type-C because it is now
the universal standard, so expect to
see more of this in future.
After passing through CON5’s internal switch, the GND connection from
CON4 also passes through Mosfet Q1
before reaching circuit ground. This
provides reverse supply polarity protection, although that should not be
necessary for the USB socket as the
socket itself should guarantee the correct polarity. However, it is helpful if
powering the circuit via barrel connector CON5 or header CON6.
In those cases, as Q1’s gate is connected to the +5V rail and incoming
DC supplies via two 10kW resistors, it
will only conduct if the incoming supply polarity is positive. If it is negative,
Q1’s gate will be pulled negative, Q1
will be off, and the whole circuit will
be unpowered, floating at the positive
DC supply voltage (that was erroneously connected to the negative input).
There are two 10kW pull-up resistors for the gate so that Q1 will switch
on regardless of whether the USB connector is used (feeding 5V directly) or
one of the other inputs, which feed 5V
Programming the CD74HC4059 counter
This counter is quite complicated as it includes a prescaler plus a three or four
digit ‘decimal’ main counter that varies in how you can use it. The prescaler can
divide by between 1 and 10 in five different modes. However, which prescaler
mode you choose affects what values you can have in the main counter’s top
(thousands) digit.
For example, if you have a divide-by-10 prescaler, the main counter only has
three digits (up to 999). If you use one of the other prescaler values, the main
counter has four digits, with more options as the prescaler division ratio becomes
smaller.
The lower three decimal digits of the main counter can always be preset with
a value from 0 to 9. Depending on the mode, the overall maximum division ratio
is either 9999 (eg, with the prescaler in divide-by-10 mode) or 15999 (with the
prescaler dividing by a power of two).
It is actually possible to divide by a much higher number than that because
the ‘BCD’ or ‘binary coded decimal’ counter stages that it initially seems can only
count up to 10 are actually full binary counters that can count up to 16. So, while
programming it is trickier, it can be set to divide by up to 21,327.
Luckily, our desired division ratio of 10,000 is relatively easy to set up. We
could have used a prescaler value of 10, leaving a three-digit main counter.
While dividing by 1000 with three digits seems impossible, we could have set
the top ‘digit’ to 10 (because the actual limit is 15), which would have given the
desired result.
In the final design, we use a prescaler ratio of 8, leaving us with four digits for
our main counter, although the top digit can only be 0 or 1. That’s fine because
we set the main counter to divide by 1250, as 1250 × 8 = 10,000.
The prescaler value of 8 is selected with KA low, KB low and KC high as per
Table 1. We then program the top digit of the counter using J4, which we set
high, to 1. The remaining three digits are set to 2, 5 & 0, as shown in Table 2.
One ‘gotcha’ when setting up this counter is that, while the thousands digit for
the counter is set using low-numbered inputs (J2-J4), the hundreds digit is set
using the highest-numbered inputs (J13-J16). So the digits do not appear at the
inputs in order, except in the mode when the prescaler can divide by up to 10.
42
low-dropout regulator REG1. Zener
diode ZD1 prevents damage to Q1 as
its gate is only rated to handle ±12V.
This method has a much lower voltage loss than using a series diode (a few
millivolts instead of 300mV+), allowing you to use a supply barely above
5V while still getting a regulated 5V at
the output of REG1 to power the rest
of the circuit.
Construction
While it uses mainly SMD parts, the
board is relatively easy to assemble as
they are all fairly large. Experienced
constructors can gather the parts and
solder them to the board as shown in
overlay diagrams Figs.2 & 3. We suggest fitting all the SMD parts to one
side of the board, followed by the
other, then the through-hole parts. It’s
best to start with the top, as more parts
are on that side.
The Frequency Divider is built on
a double-sided PCB coded 04112231
that measures 64 × 37.5mm. We recommend soldering IC1-IC5 in numerical
order, then ZD1, Q1, REG1, the USB
socket (if fitting it), then the top-side
capacitors and resistors.
With the ICs, check very carefully
that each one is the right way around
before soldering them; most will have
a pin 1 dot or bar. Use a magnifier to
find them if necessary. As shown in
Fig.2 and on the PCB, in each case, pin
1 faces towards the top of the board or
to the left (for IC5).
There is one 1μF capacitor on this
side; the rest are 100nF. As mentioned
earlier, you can leave off the 5.1kW
resistors if you aren’t using the USB
socket. Also note that unlike the TypeB USB sockets we’ve been using for a
while, these Type-C sockets have no
locating posts that slot into holes in
the PCB, so you will have to be careful
to align all its pins and tabs with the
pads before soldering more than one.
There are various ways to solder
these parts: with solder paste and hot
air, solder paste and a reflow oven,
solder paste and a hot plate or regular solder and a regular iron (which
is how we did it). If using a standard
iron, we strongly recommend having a good quality flux paste on hand,
plus some solder wick, as they make
it much easier.
There is no ‘right’ way to hand solder SMD ICs, but here is how we did
it, starting with the ICs. We placed a
little solder on one of their pads, then
Practical Electronics | March | 2025
Compact Frequency Divider
Figs.2 & 3: we recommend
fitting all the SMDs on
the top side first. Ensure
all the ICs are orientated
correctly and leave the
SMA connectors, DC
socket and headers until
after you’ve populated
the underside of the
board. There are not as
many components on
the underside; just the
comparator IC, passives
and the dual diode.
slid them into place while heating that
solder (to keep it molten). Removing
the iron, we checked that all the leads
were centred on their pads. If not, we
reheated that solder joint and gently
nudged the IC towards the correct position, rechecking each time.
Once the IC was positioned correctly, we soldered a couple more
pins, then spread a thin layer of flux
paste along both rows of pins, loaded
the soldering iron tip with some solder and dragged it along the pins. Each
one took up the right amount of solder,
making quick work of all the joints.
Only a few joints got too much solder, resulting in a bridge to an adjacent
pin. We removed the bridges using a
bit more flux paste and an application
of clean solder wick.
You could use a slightly different technique, where you clamp the
device in the correct location using
a clothes peg, haemostat clamp or
similar, tack it down, then solder
the remaining pins. That technique
involves more set-up time but less
trial-and-error.
Once the ICs are in place, you can
solder the remaining three-lead and
two-lead components with a similar
technique. Just make sure you let one
joint solidify (which can take a few
seconds) before making the other, or
you could end up pushing the parts
out of position.
With all the parts in place, clean the
board with some flux cleaner (or pure
alcohol if you don’t have a specific
flux cleaner), let it dry and inspect all
the solder joints to ensure you haven’t
missed any imperfect/incomplete
joints or bridges. Then flip the board
over and solder the parts on the other
side using a similar technique.
There is just one chip (IC6) on the
underside, plus one dual diode in a
three-pin SOT-23 package and 10 passives (resistors & capacitors). Take care
with the orientation of IC6; its pin 1
goes towards the nearest PCB edge.
Some parts are close to IC6, so it’s
best to solder IC6 first, then the components right next to it, followed by
those further away. Again, when finished, clean off the flux residue and
inspect your work.
Finally, flip the board back over and
solder the SMA connectors, the threepin header for LK1, plus whichever of
CON5 and CON6 you will be using. If
leaving CON5 off, you will need to solder the short wire link shown in red
in Fig.2 and the PCB silkscreen, or the
board won’t get power.
Note that you could leave SMA
connector CON2 off if you don’t need
or want the 1MHz output.
Testing
The board should draw under
20mA when powered up. If you have
a current-limited bench supply, set it
to 6V and at least 30mA and connect
it to CON5 or CON6. If it goes into current limiting, switch it off and check
for faults. If you don’t have a bench
supply, use a regular DC supply fed
through a DMM set to measure milliamps and switch off if the current
shoots up when you power it up.
Lacking such a supply, you just have
to YOLO it: plug a suitable power supply in and check if LED1 lights. If it
doesn’t, unplug the cable and try to
figure out why. If it does, proceed with
the following checks.
Assuming the current draw is OK,
check the voltage between the shell of
one of the SMA connectors (ground)
and the large tab of REG1. It should
be close to 5V. If it is below 4.75V or
above 5.25V, check the soldering on
REG1 and its adjacent bypass/filter
capacitors.
If it isn’t drawing any current and
the LED is off, that probably means that
Q1 is not conducting. You can verify
that by measuring the voltage between
Table 1 – 74HC4059 modes (● must be set up with Master Preset mode first)
KA
KB
KC
Prescaler ratio
Preset inputs Counter thousands digit
Preset inputs
Maximum count
1
1
1
2:1 to 1:1
J1
0-7
J2-J4
15,999 (17,331 extended)
0
1
1
4:1 to 1:1
J1, J2
0-3
J3, J4
15,999 (18,663 extended)
1
0
1
5:1 to 1:1 ●
J1-J3
0-1
J4
9,999 (13,329 extended)
0
0
1
8:1 to 1:1
J1-J3
0-1
J4
15,999 (21,327 extended)
1
1
0
10:1 to 1:1
J1-J4
0
-
9,999 (16,659 extended)
Table 2 – our 74HC4059 configuration
KA
KB
KC
Prescaler preset (J1-J3)
Thousands (J4) Hundreds (J13-J15)
Tens (J9-J12)
Units (J5-J8)
0
0
1
000 (0)
1 (1)
0101 (5)
0000 (0)
Practical Electronics | March | 2025
0010 (2)
43
Constructional Project
your supply negative and the shells
of the SMA connectors. There should
be very little difference. If you measure the full supply voltage, check that
you’ve applied power with the correct
polarity. If you have, there is a fault
around Q1/ZD1.
Finally, assuming the current draw
is OK and the 5V rail is close to 5V,
feed a signal with a known frequency
into CON1 and check for 1/10th that
frequency at CON2 (if you didn’t fit
CON2, you can probe its centre pin).
If that checks out, apply 10MHz to
CON1 and look for a 1Hz output at
CON3. If it’s missing, make sure JP1
is inserted in one of the two possible
positions.
Remember that, depending on your
test instrument, it could take several
seconds to register a reading of such
a low frequency.
If the board isn’t behaving, common
problems to look for are solder bridges,
pins where the solder hasn’t adhered
to the PCB pad below, or incorrectly
orientated ICs (we did warn you!).
Usage
There isn’t much to it: connect your
reference signal source to CON1 and
feed the output at CON3 to your GPS
clock(s) or other devices needing 1Hz
pulses. Move JP1 if necessary to get the
desired duty cycle, although almost
any device expecting a 1PPS signal
should work in either position.
We suggest housing the board in a
small diecast aluminium box with the
case connected to circuit ground to
minimise EMI pickup. However, we
tested it as a ‘bare board’ and it performed well in our lab. The SMA connectors are arranged along one edge,
so you can mount the board such that
they project through holes in the case,
then add a chassis-mounting DC socket
wired to CON6.
The four corner mounting holes will
provide a convenient way to attach
the board to the inside of such a box.
If you need to make the board as small
as possible, the tabs those holes are on
can be cut off with a hacksaw or similar (but don’t breathe the resulting dust
Parts List – 10MHz Frequency Divider
1 double-sided PCB coded 04112231, 64 × 37.5mm
3 right-angle or vertical through-hole SMA connectors (CON1-CON3)
1 SMD USB Type-C power-only socket with six pins (CON4) ●
1 PCB-mount DC barrel socket (CON5) ●
1 2-way polarised header, 2.54mm pitch (CON6) ●
1 3-pin header, 2.54mm pitch (JP1)
1 jumper shunt (JP1)
● omit any of these power input connectors that are not needed
Semiconductors
3 (CD)74HC4017(M96) high-speed CMOS Johnson decade counters,
narrow body SOIC-16 (IC1, IC2, IC4)
1 (CD)74HC4059 high-speed CMOS programmable divide-by-N counter,
wide body SOIC-24 (IC3)
1 MC74VHCT50A hex CMOS non-inverting buffer, SOIC-14 (IC5)
1 TLV3501AID rail-to-rail high-speed comparator, SOIC-8 (IC6)
1 AMS1117-5.0 or compatible 5V 1A low-dropout regulator, SOT-223 (REG1)
1 AO3400 30V 5.8A N-channel logic-level Mosfet or equivalent, SOT-23 (Q1)
1 SMD LED, SMA/M3216/1206 size, any colour (LED1)
1 BZX84C5V6 5.6V 1% tolerance zener diode, SOT-23 (ZD1)
1 BAT54S dual series schottky diode, SOT-23 (D1)
Capacitors (all SMD M3216/1206 size 50V X7R)
8 100nF
1 1nF
1 1μF
Resistors (all SMD M3216/1206 size 1%)
1 10MW
1 47kW
4 10kW
2 5.1kW (only needed if USB socket is fitted)
1 1kW
1 220W
3 49.9W, 51W or 75W (to suit desired input/output impedance)
10MHz Frequency Divider kit from Silicon Chip (Cat SC6881): ~$48 (£24) + P&P
44
and cut them outdoors or in a wellventilated area).
Most oscilloscopes, spectrum analysers, high-end frequency counters
etc will have a pretty accurate 10MHz
output; it’s usually specified as something like ±1ppm. That isn’t as good
as a GPS-disciplined oscillator but it’s
still very precise. You will likely need
a BNC-to-SMA cable to make this connection. You may need a second similar cable for the 1Hz output, depending on where it’s going.
Lacking that, some newer DSOs
have a waveform generator output
that can generate a 10MHz sinewave
or square wave (either is suitable).
They tend to have quite a bit less stability and more jitter than a 10MHz
reference output. However, an actual
GPS 1PPS signal has jitter, so if you
are using this board to emulate such
a signal, you generally needn’t worry
too much about it.
You can also get connectors that
break a BNC connection out to screw
terminals if you’re going to feed the
1PPS signal to pin headers or similar.
If you want to feed the 1Hz output of this board to multiple clocks
or other devices, given its low frequency and the fact that most 1PPS
inputs will have a high impedance,
you will probably just need to ‘fan it
out’. You could even omit CON3 and
solder wires directly to its pads. We
mainly provided the SMA connector
for convenience in hooking it up to
prebuilt test equipment.
If you need to split the 10MHz output of your test equipment to go to
multiple locations, consider building our Frequency Reference Signal
Distributor (April 2021). However,
note that the design won’t work on
the 1Hz output without modification as it is AC-coupled at the input
PE
and outputs.
We used rightangle SMA connectors.
Practical Electronics | March | 2025
AI-enabled holograms
Techno Talk
Only a few years ago, most of us would have thought the technology
behind life-sized AI-enabled human holograms was far away, in the
distant future. Well, tomorrow must have come early, since I just saw
people holding a conversation with such a beast!
I
feel like I’m straddling multiple
technological epochs and I’m not as
limber as I used to be. For example,
I was just reading a very interesting
6-part series on the Rise and Fall of
Heathkit (https://pemag.au/link/ac3c)
written by my friend Steve Leibson.
The 1960s and 1970s were golden
years for Heathkits. These ranged
from entry-level projects like building a crystal radio or an oscillator to
practice Morse code, all the way up to
advanced kits like ham radio transmitter/receivers and colour televisions.
As Steve says, “Many engineers started their budding careers by building
one or more kits made by the Heath
Company”.
I remember those far-off times as if
they were yesterday. Meanwhile, I currently maintain a tenuous toehold in
the present, in which artificial intelligence (AI) and machine learning (ML)
applications are rampaging across the
technological landscape. Things are
currently moving incredibly fast in
AI/ML space, where no-one can hear
you scream. For example…
Deploying AI at the edge
It’s common to hear the term ‘edge’
used in the context of embedded systems and the internet of things (IoT).
This means different things to different people, but I’m talking about
what I think of as the ‘extreme edge’,
that is, the point where the internet
‘rubber’ meets the real-world ‘road’.
We are currently sitting on the horns
of a dilemma, and it’s jolly uncomfortable, let me tell you. The crux of
the problem is that almost everyone
wants to add AI/ML to their embedded/edge applications and devices,
but very few people have the necessary expertise to add AI/ML to their
embedded/edge applications and
devices.
Just saying “crux” causes (what
I laughingly refer to as) my mind
to reflect on Frank Zappa’s playful
and enigmatic line: “The crux of
the biscuit is the apostrophe”, from
his 1974 album Apostrophe (‘). This
captures Zappa’s genius for making
Practical Electronics | March | 2025
the mundane seem profound and
the profound seem mundane. But
we digress…
Recently, I had quite the fascinating conversation with the folks at
DeGirum (degirum.ai). These chaps
and chapesses have a cunning solution to this problem.
First, they have a “Model Zoo” that
contains 1,000+ pre-trained AI/ML
models ranging from things like people
detection, face detection, age estimation, gender classification, and emotion
classification (happy, sad, angry…) to
vehicle detection, number (license)
plate detection, pothole detection, fire
and smoke detection, intruder detection and weapon detection.
These models, which can be used in
isolation or in combination, address
the needs of a vast range of markets
and applications. That includes ‘smart’
cities, offices and homes; construction,
infrastructure and industrial automation; retail analytics and digital
signage… the sky’s the limit.
The folks at DeGirum also have a
hardware-agnostic PySDK (Python
software development kit). The clever
bit is that they have a collection of
supported hardware platforms ‘in the
cloud’. Developers can combine their
application software with DeGirum’s
pre-trained models and run everything remotely on different platforms
to determine the optimal cost/performance tradeoffs.
Best of all, this is free! People pay
based only on the number of PySDK
runtime instantiations that are eventually deployed in real products in
the field.
Closer than we think
Did you ever see the 2002 movie interpretation of H. G. Wells’ The Time
Machine? There’s a scene set in a
futuristic library where our hero converses with an AI-enabled hologram.
You can find this moment on YouTube
(https://youtu.be/CQbkhYg2DzM).
When I first saw this movie (the
day it came out), this level of technology seemed to be something that
was a long, long way in the future.
Max the Magnificent
Well, I was just chatting with Edward
Ginis, who is the chief technology
officer (CTO) at a company called
Proto (protohologram.com). They
essentially have this technology in
the here and now!
Here’s how it works in a crunchy
nutshell. First, they video someone
talking for a few minutes. Let’s say
that someone is me. Based on this,
their AI can extract my ‘vocal signature’ for use in a text-to-speech role.
It can also determine how my lips
and the muscles on my face interact with the various spoken sounds.
This includes the way I smile, frown,
blink etc. It’s also watching the way I
move my hands and arms; my entire
non-vocal communication or body
language.
This is where things get extremely clever. Suppose you were lucky
enough to be having a live conversation with me. While you were talking,
although it wasn’t my turn to speak,
I would still be engaged in the conversation with my body language:
smiling, frowning, nodding in agreement… that sort of thing. Also, my
mind would be constantly evaluating my potential responses based on
what you were saying.
Now suppose that you were talking to Proto’s AI hologram version
of me. While you were talking, the
hologram would be performing its
non-verbal communication activities. Also, it would be deciding how
to respond.
This all happens in real-time (not
like today’s Alexa-like assistants that
wait for you to finish talking, then
upload what you’ve said, and then
reply after a few seconds’ delay).
This means the AI hologram will
respond immediately—sometimes
before you’ve even finished talking—
just like in a real conversation.
Also, all visual aspects of the AI
hologram—lips, facial muscles, hand
and body gestures—are synchronised
with whatever it’s saying.
And just what will it be saying? I’m
glad you asked. I’ll tell you about that
in my next column.
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