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  1. flippineck

    One shot one day segment timer

    Not sure if anybody makes a timer like this.. You know those plug-in mains timers that work mechanically, like a 24hr clock face & have a ring of tiny 15-minute segments you can click out for 'on' and in toward the centre for off? I'm looking for one that only stores 'on' settings for a day on...
  2. flippineck

    reflowing a board

    I have a board which was built around 2000. It's a control board for a boiler. It has some kind of microprocessor (size and format of a Z80), and a bunch of assorted discrete passive components and semiconductors - some surface mount, some with thru hole wire leads. I'm suspecting the fault I...
  3. flippineck

    LC Resonance Signal Origin Detector

    Would I be able to conveniently use a small coil of wire (with or without a ferrite etc. core) in parrallel with a capacitor to detect the strength of a radio transmission at a particular frequency, from a particular direction, if I had some kind of shielding behind it? I was thinking of...
  4. flippineck

    Coax Collinear Antenna

    For example http://www.balarad.net/ There seem to be many variations of designs, many plans on the net for this type of vertical omnidirectional radio antenna. They all seem to share the common features, most notably a chain of elements each one half wavelength long. Loads of plans on the net...
  5. flippineck

    LED control chip?

    Image attached, it's the 8-legged chip I'm trying to identify. The board is a power supply taken out of the base of an E27 screw-in domestic lightbulb. The closest I can get to ID'ing it by sight is: 1st line Character 1: "C" or "E" Character 2: "P" of "F" Characters 3 thru 6: Definitely...
  6. flippineck

    Dimmable mains LEDs

    Referring here to the sort of LED lamp which is commonly available in supermarkets etc, usually with a Bayonet or Edison Screw type connection, for domestic 240V AC use, and using a multitude of small discrete LEDs (rather than 'LED filament' or other new fangled technology) I guess similar is...
  7. flippineck

    Solar panels in series

    Let's say I have 2 identical solar panels, both illuminated the same, and connected in series. Let's say each panel is generating 17 Volts, and the + & - ends of the whole array are connected together through a 10 ohm resistor. Let's say at the same level of illumination, one single panel...
  8. flippineck

    Good basic breadboarding kit?

    Long time ago I used to collect all kinds of components.. used to strip down circuit boards etc & painstakingly store them all away in drawer cabinets etc. And I had a nice collection of tools, some bought new, some secondhand, even some hand built.. oscilloscope, capacitance meter, logic...
  9. flippineck

    Missing feature - voltage level monitor

    It's a question about my solar energy setup again. I used to have a cheap ebay MPPT charge controller to regulate the power coming from my solar panels into my 2 leisure batteries configured as a nominal 12V parallel pair. Discovered it wasn't MPPT, it was a PWM design. Went out and bought a...
  10. flippineck

    cells in mixed connection

    Can anyone explain the voltage arising from a mix of batteries. for example, see sketch
  11. flippineck

    Lead-Acid temperature compensation in charging

    I have this new charge controller for my solar power system. One of it's features is 'temperature compensation' and it has something to do with changing how the battery is charged depending on it's temperature. The 'temperature compensation' feature is adjustable in programming and is measured...
  12. flippineck

    Resistance of dark solar panel

    I have two identical Chinese solar panels, which both claim to have "inbuilt diode prevent the reverse of charging situation". Open circuit voltage quoted as around 19V, quoted current around 5A. Let's say I connected the two in series, and illuminated both with bright sunshine sufficiently...
  13. flippineck

    Switching 240v source automatically

    Source #1 is a solar power setup as follows: 3 x 80 watt solar panels "nominal 12V" in parallel One allegedly MPPT but probably PWM, 10A solar charge controller 2 x 12V 110Ah lead acid deep cycle batteries in parallel one 1000W cont / 2000W peak pure sinewave inverter (which can realistically...
  14. flippineck

    I've got to do something with it.. can't just leave it hanging

    I just bought a nifty model helicopter from Toys R Us. It works on 27MHz and has aerials roughly 60cm long, one on the transmitter, and a loose wire one hanging from the helicopter itself. Flies great! Big fun & my 5 YO lad loves dad's heli, constantly wants control ;-) Only trouble is, this...
  15. flippineck

    Repurpose grid-tie technology for local scalability?

    Could I connect together the outputs of multiple seperate grid-tie power inverters to get more power? They'd all be fed off the same battery bank, charged by solar PV. For instance say I have 5 identical inverters each rated at 1kW continuous, 240V 50Hz, with grid-tie capability.. could I use...
  16. flippineck

    Mins from CR2032 @ 200mA?

    For how many minutes could a CR2032 coin cell supply 200mA? What kind of miniature cell or battery is best at supplying this sort of current for the longest time? It's to run a 9V 200mA camera on a pet's collar, so the power supply must be as small and unobtrusive as possible. Maybe I could...
  17. flippineck

    Understanding the nature of the electric field

    Reading a discourse on the nature of the electric field, I keep running into discussions of discrete charges 'creating' an electric field in the space surrounding them. http://www.physicsclassroom.com/Class/estatics/u8l4a.cfm https://van.physics.illinois.edu/qa/listing.php?id=414 Is it such...
  18. flippineck

    Android cell info

    does anyone happen to know if you can get an android powered cellphone to divulge current carrier frequency information?
  19. flippineck

    Looking for 1990 Kenwood A-54 amplifier parts

    Fault symptoms: Volume knob (which is motorised and can rotate under IR remote control command) has a number of regions of travel where loads of dropout (R, L and both channels randomly) occurs upon movement. Can only reliably set volume at certain levels. Dropout also occurs sporadically when...
  20. flippineck

    Micro soldering

    I'm embarking on a harebrained project to try adding a decent RF connector to a smartphone that doesn't have one. It's a Samsung Galaxy S3. It has a test RF connector on the circuit board which is accessible if you remove the battery cover. It's not a socket though, it's a purpose designed test...
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