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  1. STEVE2

    PIC diode tester

    Any one have any experience with PICs?  I want to test 16 diodes at once.
  2. STEVE2

    PIC diode tester

    I am looking to build the PIC diode tester described on the site. I would like to expand the project to test more than one diode at once.  Looking at the schematic it looks like it uses 4 outputs and 1 input from the 16F84.  Looking at the datasheet for this PIC, I could expand it to test 2...
  3. STEVE2

    Led display Digital Voltmeter question

    This may already have been answered on previous pages ... but don't have time to read all 19 at the minute! In the power supply which supplies the +/- 5 V (schematic attached) what are the two 1 K resistors for? Thanks
  4. STEVE2

    Photodiode structure

    http://www.osioptoelectronics.com/products/02-07_PDiodeChar_OSIOpto_0.pdf "To form an ohmic contact another impurity diffusion into the backside of the wafer is necessary. The impurity is an N-type for P-type active area and P-type for an N-type active area."
  5. STEVE2

    Photodiode structure

    Found the answer ... It's an ohmic contact to reduce the resistance between the semi-conductor and the metal contact.
  6. STEVE2

    Photodiode structure

    On a photodiode does anyone know what the N+ region between the cathode and the N substrate is for? Thanks in advance!
  7. STEVE2

    Radio controlled clock

    Would anyone know how to go about designing a circuit to decode the MSF signal from Rugby (UK) to create a radio controlled clock? I would like to create a project displaying date and time using the signal transmitted from Rugby. Thanks in advance
  8. STEVE2

    Need Help Alligning IR lasers

    You could also introduce a small circuit which indicates when the IR beam passes over the photodetector.  Circuit consisting of an Op Amp and an LED (visible one!) for the output. Attach the input of the Op Amp across the photodetector, turn the IR diodes on, try directing the IR diode towards...
  9. STEVE2

    'Op Amps for everyone'

    I thought I would post this .pdf as I think it's quite good and explains op amps really well.  It explains them right from the beginning through to complicated stuff like active filters etc... Let me know what you think! [attachment deleted by admin]
  10. STEVE2

    Idea for LED Rainbow Light

    Hi Stephen, I know that the idea you have already exsists.
  11. STEVE2

    How small will they go?

    Just thought I'd share this with everyone coz I thought it was pretty amazing!  A tiny ScanDisk memory card (256 MB) for my mobile, will miniaturisation ever find a limit?
  12. STEVE2

    Pb-free soldering

    I have just been browsing on RS and found that they have information on the changes to Pb-free solder...
  13. STEVE2

    Pb-free soldering

    I'm haven't seen the affects at first hand of what happens when the two solders are cross-contaminated, but perhaps there won't be much chance of this happening as everyone will have to use lead-free solder and Pb solder will become obselete ???
  14. STEVE2

    T Flip Flop converted to D Flip Flop

    (couldnt work out how to attach two files at once!!)
  15. STEVE2

    T Flip Flop converted to D Flip Flop

    T flip flops and D flip flops are just JK flip flops with inputs connected slightly differently. I have attached schematics of each type of flip flops. Whether you can convert them depends on how close you can get to the inputs of the JK, I think this would be impossible if the flip flop...
  16. STEVE2

    Pb-free soldering

    I thought I would post the implications of Pb-free soldering I have found on an industrial scale. This is more for interests sake but also to see if anyone has found similar attributes in a more 'domestic' setting. Issues which can arise are: the flux used; corrosion of equipment; higher...
  17. STEVE2

    Pb-free soldering

    I don't think that anyone has started a topic on this as far as I can see ... I was just wondering whether anyone had any experience with using lead-free solder yet? There have been various directives put forward by the European parliament, such as the RoHS (Restriction of certain Hazardous...
  18. STEVE2

    Flickering dimmer switch

    Woopsey !! I'm afraid I've told a bit of a fib ... I have just finished dismantling the dimmer and lights. On closer inspection the 6 spots are infact low voltage halogen lights cunningly disguised as mains spots (they are hidden in behind frosted galss). They are 12V 10W bulbs (6 bulbs =...
  19. STEVE2

    Flickering dimmer switch

    Yea they are still dim when at maximum brightness, how would I test the diac & triac to see if they are working correctly? One of the bulbs has just blown !! I'll have a look at the power rating of the switch and the wattage of the bulbs attached in the morning (on GMT here!) thanks
  20. STEVE2

    Flickering dimmer switch

    I have recently installed a dimmer switch to control a circuit of 6 lights (spots) running off the mains (not low voltage lights), but when the dimmer is switched on the lights continuously flicker. It's as if the switch isn't sensitive enough. Is there anyway of adjusting the switch so that...
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