| Answers to
Frequently Asked Questions
Stock code:
 YD85G
- Q: What are the pin connections on the
YD85?
A: They are marked on the underside of the board. From left to right, with the
terminals facing towards you, the connections are:Out, V+, Gnd.
WW60
- Q: What are the
markings on a tantalum bead capacitor, and how is it polarised?
A: The inverted L
indicates the positive leg on the device.
VH00A
- Q: What can I do with the PICSTART Plus
development system and how does it work?
A: Information on the PIC website,
http://www.microchip.com, or see the PDF file on this CD.
CR44X
- Q: How do you program a keyfob to
CR44?
A: (1)Push the programming switch until the LED flashes, and release. (2)Within 5
seconds press the keyfob button until the LED stays on and release. Program a second keyfob (within
10 secs) following (1) and (2). (3) Press program switch 3 times to exit.
LT41U
- Q: My priority quiz buzzer keeps
going off on its own. What can I do?
A: Replace R1-R9 with 5k6, 0.25w resistors and
install a 0.5uf, 20v capacitor in parallel with R15 to filter PSU. This has been tested to 25m
length with unshielded cable satisfactorily.
Q: How can I produce a lower bass
extension on my closed box?
A: Port the box. Use bassbox to tuned cabinet frequency and
bass extension down, by entering the box size into custom vent dimensions, then programme will
determine port size. Shape can be altered in port dimension page.
LP56L
- Q: What FETs replace the obsolete TR6 and
TR7 from LP56?
A: AY54 (ECF10P16) will replace TR7 and AY56 (ECF10N16) will replace TR6
RC88
- Q: What is the RMS power rating for the
RC88?
A: It is 70WRMS. Each unit is tested for 100 hours at this power. The box that
this driver comes in says 50W but Audax assures us it is 70WRMS.
AF24
- Q: Why is my AF24 shutting down in
bridge mode?
A: Normally it's because people expect to use it into a 4 Ohm load, where
the amplifier can only handle an 8 Ohm load when in bridge mode. When used at 4 Ohm it will work
for a while before the protection cuts in.
Q: How do I fit my ignition cut out on
my alarm to my diesel vehicle?
A: You will have to break the pre heater circuit, instead
of the coil on a petrol engine. Most Haynes manuals will show the customer the circuit.
Q: Are sensors for alarm panels
Normally Open (NO) or Normally Closed (NC)
A: The sensors for the alarm panels we stock
are usually Normally Closed, although anti tamper switches and help / panic buttons are Normally
Open. Some electronic sensors may be set for either mode.
ZG67
- Q: What are the jumper settings for
the ZG67?
A: The jumper settings are printed on the back of the PCB.
Q: What happens if my bell box wiring
is cut on a wired alarm e.g. burglar etc?
A: Most wired alarm systems have tamper
protection (security loop) between the alarm panel and the bell box, which, when cut or tampered
with will trigger the bell box and/or the main alarm panel.
Q: Can I charge my 12v battery from a
12v solar panel?
A: Not directly. You would need at least 14 volts or higher output from
your solar panel source to charge a 12 volt battery; therefore two panels would be necessary, wired
in series with a diode to prevent the battery discharging into the panel.
Q: Which aerial do I require for
Channel 5 inside the M25 in Essex?
A: The aerial would be group `A`. GK16S from Maxview
would be O.K.
Q: What type of fuse should I use to
feed the primary winding of a transformer?
A: Under normal circumstances you would use
anti -surge fuses, as these are ideal to deal with the switch on surge from a transformers primary
winding.
Q: How do I connect my transformers
secondary windings in parallel to increase the output current?
A: Connect the start of
the first secondary to the start of the second secondary (call it 0 volts). Then, the finish of the
first secondary can be connected to the finish of the second secondary (call it 12 volts for
example). E.g. 0-12, 0-12 transformer
LK36
- Q: Is it possible to modify the
auto-waa effects unit?
A: We are unable to offer modifications on Maplin kits.
Q: I need parts for the K7105 handheld
scope, but they are not in the catalogue!
A: Velleman parts can be ordered through our
spares dept.
Q: Do you have a 10uF motor start
capacitor?
A: No we don`t. However, if you have room to install two 5uF capacitors in
parallel this will have the same effect.
FY81
- Q: Is FY81C series or parallel
resonance?
A: To operate at its stated frequency it needs a 30pF capacitor in parallel
therefore it is a parallel resonant crystal.
Q: Do our xenon flash tubes have any
polarity (Anode and Cathode) electron flow?
A: According to our suppliers of xenon flash
tubes; our tubes are not polarized as regards to electron flow and therefore the tube life should
not be compromised.
Q: What is the small self-adhesive foil
(spiral) track component supplied in my kit?
A: The foil track component is actually a
security tag put in the bag of kit components to reduce stolen goods from shops, etc.
Q: Can NiMH batteries be recharged on a
NiCAD charger?
A: It is possible to charge NiMH batteries on a NiCAD charger at a
trickle charge (10 hour rate). We do not recommend NiMH to be charged at a fast rate.
FJ06
- Q: Is the video/audio belt drive measured
across the total diameter or is it just an internal measurement?
A: The measurement is
across the diameter as a whole. If the old belt is broken, measure it's length and divide that
measurement (less 5mm for large belts) by 3.141.
CY81C
- Q: What microphone can you
recommend for stage use?
A: A microphone with good dynamic performance, which is also
durable: e.g. order code CY81C.
Q: Can ATC cameras be used
outdoors?
A: Not without weather proofing i.e. using an external camera housing.
Q: Do we stock a multimeter which reads
down to 50Hz on the frequency range?
A: No, the minimum frequency our meters read down
to is 2KHz.
GS81
- Q: What is the pin out for
GS81?
A: Reading left to right ,notch at the bottom: 1= +5, 2=+12, 3=0v, 4=-12, 5=- 5v.
Q: How is the voltage/current affected
when I connect LED`s in series or parallel?
A: In series, LED voltages are added
together although the current stays at 20mA approx. In parallel the LED current drain adds up for
each LED but the voltage remains the same at approximately 2 volts.
Q: Do you stock manufacturers data
sheets?
A: Yes, they can be ordered via our mail order service if they are not on this
CD in PDF format.
Q: My PIR does not give much distance
on the range that it detects.
A: PIR`s should be fixed approximately 7ft up with around
20 degrees down angle for optimum performance.
UG00A
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