The design seems very good but
would require considerable effort (and
probably extra cost) for little benefit
for my circumstances. All that I need
is a simple, reliable spark.
I know that I will have to buy a 12V
coil and battery; I just need the electronics to control the spark. I can use
the existing trigger but will need circuitry to couple it to the control module. My questions are:
1. Is a PCB available for the December 2005 Universal High Energy Electronic System, code 05112051?
2. Is there a kit available for that
project, or would I have to buy components separately?
3. Is a PCB available for the reluctor circuit?
4. Are there any components that
are not available now. If so, what are
the alternatives?
5. Are the above all available from
your Shop?
(T. H., Wallington, Vic)
● We do not recommend building the
2005/6 version of the High Energy
Ignition system as there are no longer
any kits or PCBs available. However, a
Advertising Index
Altronics.................................33-40
Control Devices............................. 9
Dave Thompson........................ 111
Digi-Key Electronics...................... 3
Emona Instruments.................. IBC
Hare & Forbes........................... 107
Jaycar.......................IFC, 11, 53-55,
..................................60-61, 99, 103
Keith Rippon Kit Assembly....... 111
revised version of that project was published in the November & December
2012 issues (siliconchip.au/Series/18),
and the PCB is still available; see
siliconchip.au/Shop/?article=464
Kits for that project may also still be
available. Check with Jaycar regarding
their kit KC5513; their website currently says “Limited quantities available in store”, and if available, it is on
sale at $19.80.
As well as the PCB, we sell the hardto-get parts such as IGBT and programmed PIC, available via the link
above. The other parts are commonly
available. The reluctor circuitry is
catered for on the PCB supplied.
Replacement SOT-223
LDO regulators
I am in the process of making the
PIC/AVR Programming Adaptor Board
(May & June 2012; siliconchip.au/
Series/24), but I can’t seem to find any
AP1117E33 3.3V low-dropout linear
regulators. Can I use an MCP17993302H/DB or LDI1117-3.3H instead?
(L. P., Sydenham, NSW)
● There are many different kinds of
compatible LDO regulators in SOT-223
packages with 1117 in their part code.
The 3.3V version of the LDI1117 you
mentioned should work. Another common compatible type is the AMS1117.
The MCP1799 will not work without modifying the PCB because it has a
different pinout (Vin, GND, Vout rather
than GND, Vout, Vin).
About power supply in
Circuit Notebook
I want to build the “Fully adjustable
power supply” circuit published in the
Circuit Notebook column, March 2004
(siliconchip.au/Article/3427).
I assume the 33Ω resistor needs to
be rated at 5W. I do not have an 18V
supply at 5A. Can I use a transformer
secondary rated at 15V 6A, giving
approximately 21V when rectified? I
could use a 1W 18V zener and dropping resistor to power the TL071. Is
there any erratum for this circuit? (R.
M., Melville, WA)
● The 33Ω resistor can be a 1/2W or
even 1/4W type as its dissipation will
be less than 30mW. There will only
be a maximum of about 0.7V across it
(the base-emitter forward voltage of
transistor Q1).
Yes, you can use your proposed
20V DC supply to power that circuit.
The TL071 can run from a supply of
up to 30V, so no extra zener clamp is
required.
Replacing components
on a failed Turbo Timer
I have a burnt-out resistor on my
Turbo Timer circuit board (November
1998; siliconchip.au/Article/4649).
It is labelled “33R [680R]”. Can you
please confirm the value of the resistor I have to replace it with? (S. M.,
via email)
● The resistor should be 33Ω 1/2W.
However, zener diode ZD1 and the 555
timer IC are possibly destroyed as well.
The burned-out resistor would have
been caused by a voltage transient that
shorted the zener diode and possibly
harmed the 555 timer.
Check if there is a short circuit
across ZD1. We suspect that it will
measure near 0Ω with a multimeter. All three components should be
replaced.
SC
Lazer Security........................... 111
LD Electronics........................... 111
Microchip Technology......... 5, OBC
Mouser Electronics..................... 13
Ocean Controls............................. 8
Rohde & Schwarz.......................... 7
Silicon Chip Shop.................88-89
Silvertone.................................... 12
The Loudspeaker Kit.com.......... 10
Tronixlabs.................................. 111
Wagner Electronics....................... 6
112
Silicon Chip
Errata and Next Issue
LEDsales................................... 111
isoundBar with Built-in Woofer, August 2022: the part code given
for the Peerless tweeters should have been BC25SC55-04 instead of
BC25SC55-06. Also, the sheet of 19-20mm thick plywood in the parts list
is arguably not required as all the pieces can be cut from the DAR pine
lengths.
Motion-sensing 12V Power Switch, February 2019: it has been reported
that the vibration switches can become unreliable (stuck ‘on’) due to
contact welding when it closes. To solve this, solder a 100Ω resistor in
series with one of the sensor leads (we suggest the thinner one). This
value seems to work well but note that it is a compromise as it must be
low enough to discharge the capacitor quickly but high enough to avoid
contact welding.
Next Issue: the December 2022 issue is due on sale in newsagents by
Monday, November 28th. Expect postal delivery of subscription copies in
Australia between November 28th and December 12th.
Australia's electronics magazine
siliconchip.com.au
