This is only a preview of the May 2015 issue of Silicon Chip. You can view 29 of the 104 pages in the full issue, including the advertisments. For full access, purchase the issue for $10.00 or subscribe for access to the latest issues. Articles in this series:
Items relevant to "Appliance Earth Leakage Tester":
Articles in this series:
Articles in this series:
Items relevant to "Balanced Input Attenuator For Audio Analysers & Scopes":
Items relevant to "4-Output Universal Voltage Regulator":
Purchase a printed copy of this issue for $10.00. |
Notes & Errata
Spark Energy Meter, February &
March 2015: the main circuit diagram shows D13 as a BAT46; this
should be a 1N4004 silicon diode.
The parts list should therefore be
adjusted: 9 BAT46 diodes (not 10)
and a 1N4004 added as D13.
On the main component overlay
(March), ZD31 is shown as 16V
whereas it should be a 12V zener
to agree with the circuit diagram
and the parts list. On the Calibrator, if there is insufficient range
adjustment for VR2 to set 250Hz,
Ask SILICON CHIP
. . . continued from page 103
you will get a nasty electric shock.
If you are sure the construction is
correct, then you can try using a 3A
slow-blow fuse or 5A standard fuse
instead of the 3A fuse. The initial
surge current when power is applied
can cause a fuse to blow.
Hot snubber in
speed controller
I have built the Full-Wave Motor
Speed controller from the May 2009
issue and 470Ω 1W resistor in series
with the 47nF capacitor across the
IGBT gets very hot. All voltages appear
normal. Can you explain or suggest any
reason? (D. M., via email).
• The resistor dissipates power as
it charges and discharges the 47nF
capacitor in the snubber network and
so it runs hot. This is normal.
You can change this resistor to a 5W
type or use a smaller value capacitor
such as 22nF 250VAC (X2 rated), if
R1 can be changed to a lower (eg,
180kΩ) or higher (eg, 270kΩ) value,
as required.
CLASSiC DAC (February-May 2013):
Fig.11 on page 39 of the April 2013
issue showed a 10Ω resistor to the
left of Q11 which should be 2.2Ω.
Also, the capacitors immediately
below Q11 should be 220µF and
1µF. These are all shown correctly on
the circuit diagram. The overlay
diagram in the online edition is also
correct.
you are concerned about the resistor
temperature.
Ultrasonic transducer
is unlikely to be faulty
I have just completed building the
Ultrasonic Anti-Fouling kit and on
switching the unit on it blows fuse
F1. Disconnecting and checking the
transducer with an ohm meter, I get no
reading across the red and black wires.
Have I been sent a faulty transducer?
What is my recourse in this situation?
(R. G., via email).
• The ultrasonic transducer should
read as an open-circuit when using a
multimeter, as this is a piezo electric
transducer that is essentially a capacitor when DC voltage is applied. So it is
unlikely that the transducer is faulty.
There can be several reasons why
the fuse blows. Firstly, with the fuse
and IC out of circuit, trimpot VR1
should be adjusted so there is 5V between TP0 and TP1.
If this is not able to be adjusted correctly, check components for correct
Advertising Index
Altronics.........................loose insert
Emona Instruments........................ 7
Hare & Forbes.......................... OBC
Icom Australia.............................. 41
Jaycar .............................. IFC,49-56
KCS Trade Pty Ltd........................ 25
Keith Rippon .............................. 103
LD Electronics............................ 103
LEDsales.................................... 103
Master Instruments.................... 103
Mastercut Technologies.................. 9
Microchip Technology..................... 3
Mikroelektronika......................... IBC
National Instruments...................... 9
Ocean Controls.............................. 8
Qualieco....................................... 59
Questronix.................................. 103
Radio, TV & Hobbies DVD............ 91
Sesame Electronics................... 103
Shapely Design.............................. 5
Silicon Chip Binders................ 76,97
Silicon Chip Online Shop............. 37
Silicon Chip Subscriptions........... 77
Silvertone Electronics.................. 10
Tronixlabs................................... 103
Wiltronics...................................... 11
Worldwide Elect. Components... 103
X-ON Electronic Services.......... 103
orientation and position. Make sure
the wire link (Link 1) is in place or
alternatively a 0Ω resistor in the Link
1 position. Check for solder bridges
that shouldn’t be there and unsoldered
joints.
Before inserting the fuse and IC2,
check that the 2200µF electrolytic
capacitor is orientated correctly (plus
SC
side toward the fuse).
WARNING!
SILICON CHIP magazine regularly describes projects which employ a mains power supply or produce high voltage. All such
projects should be considered dangerous or even lethal if not used safely.
Readers are warned that high voltage wiring should be carried out according to the instructions in the articles. When working on these projects use extreme care to ensure that you do not accidentally come into contact with mains AC voltages or
high voltage DC. If you are not confident about working with projects employing mains voltages or other high voltages, you
are advised not to attempt work on them. Silicon Chip Publications Pty Ltd disclaims any liability for damages should anyone
be killed or injured while working on a project or circuit described in any issue of SILICON CHIP magazine.
Devices or circuits described in SILICON CHIP may be covered by patents. SILICON CHIP disclaims any liability for the infringement of such patents by the manufacturing or selling of any such equipment. SILICON CHIP also disclaims any liability
for projects which are used in such a way as to infringe relevant government regulations and by-laws.
Advertisers are warned that they are responsible for the content of all advertisements and that they must conform to the
Competition & Consumer Act 2010 or as subsequently amended and to any governmental regulations which are applicable.
104 Silicon Chip
siliconchip.com.au
|