Notes & Errata
Tapped Horn Subwoofer, September 2021: the Altronics C3088 driver specified for
this design has been discontinued. Wagner Electronics (www.wagneronline.com.au)
sell suitable alternatives: the SB Acoustics SB20PFC30-8 ($55) and SB20PFCR30-8
($56.50). These cost less than the originally specified driver and give very similar
performance. The only design change required is to increase the diameter of the
driver hole from 180mm to 187mm.
Advertising Index
Altronics...............................25-28
Ampec Technologies................. 11
Analog Devices..................... OBC
Dave Thompson...................... 111
Touchscreen Digital Preamplifier, September 2021: in the circuit diagram (Fig.6)
on pages 42 & 43, the Vdd pins of IC6 and IC7 are incorrectly shown connected to
+12V. They actually connect to +5.5V.
Dick Smith Contest.................... 13
Battery Manager, August 2021: in Fig.3 on page 72, Q2 has been incorrectly drawn
with a P-channel Mosfet symbol. It is an N-channel Mosfet, like Q1 and Q3. The
gate, drain and source pins are marked correctly.
Emona Instruments................. IBC
Bush VTR103 AM/FM radio, Vintage Radio, August 2021: in the circuit diagram
(Fig.2) on pages 102 & 103, capacitor C11 should have been shown in series with
L5, not L6. This means that C11 and L6 form a parallel resonant network, not series
resonant as stated in the text. Also, the right-most label in the photo at the bottom
of p100 is wrong. It is the VHF RF amplifier load coil, not the VHF antenna coil.
Jaycar............................ IFC,53-60
Single-Chip Silicon Labs FM/AM/SW Digital Radio Receiver, July 2021: the
specified 3.3V regulator for REG2 (LM2936-3.3) has swapped input & output pins
compared to the footprint on the PCB. So if you use this regulator, install it facing
the opposite direction to that shown in Fig.5 on page 68, or mount it on the opposite
side of the PCB but with the flat side facing as shown. Also note that its part code
is incorrectly written as LP2936-3.3 in the circuit diagram, Fig.3, on page 67.
7-Band Stereo Equaliser, April 2020: an error has been found in the 7-Band Stereo
Equaliser PCB (01104202 RevB). There is a missing track between the 10nF and
2.2nF capacitors above IC7 – they should be in parallel, but only one side of the
pair is connected. This causes the second-highest band to operate at the wrong
frequency. If you have a PCB with this error, solder a short length of wire (eg, a
component lead off-cut) between those two pads. This error will be fixed with the
RevC PCB.
CLASSiC DAC, February-May 2013: revised firmware for the DAC (0110213B.HEX)
is available for download from our website. This fixes pushbutton debouncing
problems and includes changes to the IR reception code to better reject noise.
Also, some people have complained that one or more TOSLINK input LEDs light
up when there is no signal present. This is usually fixed by adding 30pF ceramic
capacitors across the empty pairs of pads near the TOSLINK receivers.
The November 2021 issue is due on sale in newsagents by Monday, October
25th. Expect postal delivery of subscription copies in Australia between October
25th and November 12th.
It is a great kit that Jaycar are still selling here in NZ. (B. N., Dunedin, NZ)
• You can look up kit information via
our Article Search feature (siliconchip.
com.au/Articles/ContentsSearch).
Enter the project name (or part of it)
in the “Name” field but watch out for
differences in punctuation etc. Searching for “Voltage Monitor” shows that
there were two kits, DSE K4608 and
Jaycar KC5424, both of which have
been discontinued.
We generally don’t sell PCBs for
projects published before 2010 because
many of them have been superseded
now (there are exceptions). In this
112
Silicon Chip
case, it has been functionally replaced
by the 10-LED Bargraph from February
2018. This later version doesn’t require
any special-purpose ICs and it is also
very flexible in its configuration. We
sell the PCB for it at siliconchip.com.
au/Shop/8/3272
It should be possible to use that to
do virtually everything the Vehicle
Multi Voltage Monitor can do. You
might want to read the article first to
determine what parts you need.
For example, the 10-LED Bargraph
calls for 10 3mm through-hole or
M3216/1206 SMD LEDs of unspecified
colour, while the Vehicle Multi-Voltage
Australia’s electronics magazine
Digi-Key Electronics.................... 3
Hare & Forbes............................. 5
Keith Rippon Kit Assembly...... 111
Lazer Security......................... 111
LD Electronics......................... 111
LEDsales................................. 111
Microchip Technology.................. 9
Ocean Controls........................... 8
PHIPPS....................................... 4
PMD Way................................ 111
SC Christmas Decorations........ 69
Silicon Chip Binders................. 81
Silicon Chip Shop...........106-107
Silicon Chip Subscriptions....... 50
Solder Master.............................. 7
Switchmode Power Supplies....... 6
The Loudspeaker Kit.com......... 10
Tronixlabs................................ 111
Vintage Radio Repairs............ 111
Wagner Electronics................... 87
Monitor uses two yellow, six green and
two red rectangular LEDs. As far as we
can tell, you should be able to fit those
same rectangular LEDs to the 10-LED
Bargraph PCB (or use 3mm round LEDs
with the same colour scheme).
You will want to set up the 10-LED
Bargraph in linear mode, using the 10
1kW resistors specified in the parts list,
just like the Multi-Voltage Monitor.
The only trick is that if you want to
achieve the 9-16V range option offered
by the Multi-Voltage Monitor, you will
need to replace R1 with a 5.6V zener
diode, with its anode connected to
ground.
SC
siliconchip.com.au
