Search results

  1. EdwardM

    boost converter

    Hi scuba14c pulsed DC usually refers to switching on and off the primary of a transformer which is supplied by a DC voltage such that when there is a change of current (switch on or off) that rate of change of current becomes available at the secondary.  The secondary is electrically separated...
  2. EdwardM

    boost converter

    Hi scuba14c I posted you some days ago but in looking back over it I didn't include the correct link, have a look at the application note, you will find that it is relevant Best of Luck Ed AN19.pdf
  3. EdwardM

    ICL7109

    Hi Junaid I'm trying to understand why all of the outputs are high - with input short circuited, after applying HBEN or LBEN do any of the outputs go low ever?  You may may need to split the circuit so that only the ICL7109 is operational, ie, remove digit outputs from the bus and ensure that...
  4. EdwardM

    Need some electronic add-on ideas for my new project (Stirling engine)

    Hi audioguru afraid I'm only slightly sideways - am Jock but live in south of England  8) Ed
  5. EdwardM

    ICL7109

    Hi Junaid before going any further, if you haven't already done so, please join the analogue input to GND (ie don't apply any input voltage), this should give a reading of 0000 Ed
  6. EdwardM

    ICL7109

    Hi Juaid the only thing I can see is that you've left pin 17 floating, in its low state all outputs would be set to 1, it's therefore worth tying this input high. Ed I'll try to answer the other questions shortly...
  7. EdwardM

    ICL7109

    Hi Junaid it is a convention on the internet that when someone writes with bold lettering it means that he or she is SHOUTING and as you're probably aware most of us react to shouter by ignoring them.  You are perfectly free to carry on using bold, no-one will stop you but it severely reduces...
  8. EdwardM

    ICL7109

    Hi Junaid no need to use BOLD, can use post a circuit diagram Ed
  9. EdwardM

    Need some electronic add-on ideas for my new project (Stirling engine)

    Hi audioguru maybe we could take the temperature differential between Canada and Oz as the input for a slightly larger Stirling engine  8) Coz last time I was in Canada my eyeballs froze (Belle Isle Strait, December) and every time in Oz, even the occasional rain was warm  ;D Ed
  10. EdwardM

    Need some electronic add-on ideas for my new project (Stirling engine)

    Hi Dazza It's an allusion to a game where two teams of hefty blokes pull in opposite directions on a rope, the winner being the team which pulls the other team beyond a set position.  :D I was thinking of something like a galvanometer/meter or something where it would be immediately clear...
  11. EdwardM

    Need some electronic add-on ideas for my new project (Stirling engine)

    Hi Dazza from the web searches I've done on the Stirling engine, it looks like it's the bees knees and someday might even replace the current internal combustion engine  :o You could try starting with a very very small motor acting as a generator and use it to light a LED, whilst not very...
  12. EdwardM

    Salvaging Computer PSU

    Hi again magatru these PSU's are excellent and have huge current capability but I believe there is a minimum current that needs to be taken from them in order for them to work.  What that current is I don't know but I suspect it's fairly low, you'll need a web search on this one and for the...
  13. EdwardM

    Project help needed ..very very simple for the lot of you probably.

    Hi fotoobscura there have been a lot of interesting suggestions arising out of your post, as a finalish one can I suggest that you try to get your local university EE department interested, because of the range of research/disciplines involved I'd have thought they'd jump at the chance, even...
  14. EdwardM

    Project help needed ..very very simple for the lot of you probably.

    Hi Alun, guesstimating the distances involved from fotoobscura's original post, I'd think the min order qty wouldn't be a problem. ebay sounds good afterwards  ;D Ed
  15. EdwardM

    Basic LDR Help Needed

    Hi tvdbon one way is to connect the 12v supply, a resistor and the LDR, and use the voltage developed across the LDR as the analogue input.  You should be able to find an datasheet/application note on the web and from that derive the necessary resistor value. Best of Luck Ed
  16. EdwardM

    Project help needed ..very very simple for the lot of you probably.

    Hi All, hate to labour the point but I will  ;D http://www.titoma.com.tw/energy_saving_light_bulbs.shtml , one example of many, the link describes a small 12v fl bulb, whilst I doubt that it would fit within the size/power/illumination constraints, I'm not sure that the other possibilities...
  17. EdwardM

    TRANSMISSION LINES

    Good thinking audioguru, sounds about right  ;D Ed
  18. EdwardM

    Project help needed ..very very simple for the lot of you probably.

    Stand-up all those who've never heard of small fluorescent bulbs, shame on you  ;D Imagine a regular bulb, about 3 ft long, now scale it down to about 4 inches, these are sold as backlights, interior illumination for cars and as part of some flashlights and for other purposes. Ed
  19. EdwardM

    Project help needed ..very very simple for the lot of you probably.

    Hi again fotoobscura having thought a bit longer about it, this may seem a bit obscure, but I'd  be tempted to look at this from the other direction and that's to work out the light level needed at the artwork to illuminate it as required taking into account any sky illumination, street lights...
  20. EdwardM

    TRANSMISSION LINES

    Hi prateeksikka I've seen the same things in several countries but never in the UK, I've always though that they were there to scare birds or pilots  ;D Ed
Top