Technical FAQ's

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

  • Q: Can I recharge the new lithium ion cells on the UG00A battery ultra charger?
    A: Unfortunately, no. This charger has not been designed to supply the specific slope rate required by lithium ion cells.

    Q: Can I drive a high impedance signal into a low impedance load?
    A: No, the low impedance load will unduly load the signal down and attenuate it. It is advisable to try and match the impedance as best as possible.


Copyright ©1995-2002 Maplin Electronics Plc. All rights reserved.