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  1. flippineck

    LM394 National Semiconductor 'supermatch' NPN pair

    LM394 datasheet https://www.farnell.com/datasheets/25507.pdf I have a simplish circuit which seems to be a long tailed pair made from an LM394 driving a galvanometer, to give an indication of circuit power. Although the occasional LM394 does appear on eBay it seems to be obsolete and expensive...
  2. flippineck

    Automatic DC supply selection?

    I have a solar array (4 x 80W panels in series) on the East facing wall of my house, and a matching array on the West facing wall. In the brightest summer sun I get about 5A at 80V. My controller has a maximum input rating of 100V/500W and it feeds a couple of 12V lead-acid leisure batteries...
  3. flippineck

    Solar panel equal/unequal siting

    I have an off-the-shelf MPPT solar charging regulator connected to a 12V lead acid battery, and two solar panels. The panels are advertised to have 'built-in blocking diodes'. I could mount both panels side by side on an east facing wall, both panels side by side on a west facing wall, or one...
  4. flippineck

    Cat collar

    Had a cat run over not too long ago :-( I had the idea of winding a suitable coil onto a cat's collar, feeding it's ends across a bridge rectifier, and using the bridge DC output to charge a capacitor or small rechargeable cell, which would then power an LED attached to the collar. The hope...
  5. flippineck

    Araldite Rapid, Cyanoacrylate & PCB material.. does it stick?

    Tried to make a cover for a hole in some unknown soft casing plastic, out of a cutout bit of clear polypropylene sheet (a chinese dinner no odle tray) Tried to stick it over the hole with Araldite Rapid which is a 5-min setting 2-part epoxy available in UK. The epoxy stuck fast to the casing...
  6. flippineck

    Type of single phase AC motor?

    I have a UK mains powered Jebao-brand pond pump. It's motor is a potted resin brick with a cable coming out, and a hole in it for the removable rotor. I have no way of knowing what is inside the resin block. The rotor seems to be a solid cylindrical lump of ferrite-type material threaded onto...
  7. flippineck

    Does anyone know ST62T40B

    STMicroelectronics ST62T40B; this is a microcontroller from around 1998 I believe It's in a generator controller "DSE530" long obsolete and unsupported by it's maker Deep Sea Electronics. The normal method of programming different user parameters into this box is by way of using their...
  8. flippineck

    Small IR gooseneck spot heater?

    Wanting to desolder WSON8 6x5mm chips without damage so they can be read with a programmer off the PCB. I can get them off ok using a hot air station and tweezers but it requires a fair time of heating at around 340'C. They have a big ground pad in the middle of the chip, sandwiched between...
  9. flippineck

    'Letraset' type dry transfers for PCB pads chemical etch resist

    Does anyone know if you can still get dry transfer sheets of various electronic component PCB pads? The ones where you place the transfer on top of the plain PCB and scribble over the IC pads etc. and they transfer onto the copper I'm hoping to make up a PCB incorporating a 1.27mm pitch row...
  10. flippineck

    Soldering temperature indicator

    On my fishtank, I have a thin plastic strip on the glass that changes colour in response to temperature. I wondered if there is something similar to assist with soldering? Thinking of soldering SMT IC's with a hot air gun. Just something additional, for comfort, to confirm once you've melted...
  11. flippineck

    Semiconductors and heat

    The first time I ever attempted an electronic construction project would have been around 1979 as a young lad. It was a beat frequency oscillator metal detector. The guy next door who was an electronics egghead decided to show me how to do it over the garden fence. My first several attempts...
  12. flippineck

    Purchasing an EEPROM programmer

    I have a chip I would like to try reading and writing to as a learning excercise: W25Q128FVPQ (WSON package) https://pdf1.alldatasheet.com/datasheet-pdf/view/506494/WINBOND/W25Q128FV.html I'd like to purchase an EEPROM flash programmer for the purpose. It would be nice if the programmer I buy...
  13. flippineck

    Anyone know of a good, very basic, cheap electronic sketch pad?

    They say a picture paints a thousand words. Often find I'm trying to describe something in words where a simple circuit diagram would be far preferable. Finding it hard though, to effortlessly come up with a quick diagram on my PC (Linux OS) when the need arises. There's a million solutions...
  14. flippineck

    Single 3.3V Inverter

    Looking for a single channel inverter that will take as a square wave input, a 0V level which rises to 3.3V for one second and then drops back to 0V, and convert it to a 3.3V square wave output which falls from an initial constant 3.3V, to 0V for one second before rising back to 3.3V The input...
  15. flippineck

    Low power bistable latch arrangement

    I have a timeswitch module that provides a TTL voltage signal to the 70Ω coil of a SPDT relay. One end of the relay coil is fed with +5V from a buck converter chip, which in turn gets it's power from a 6V battery. The other side of the relay coil is connected to 0V (common to battery and buck...
  16. flippineck

    Power switching relay

    Trying to find a DPDT non-latching relay with contacts rated 250 V AC / 40A and ideally a coil able to operate at either 5V DC, or else around 240 V AC Closest I have found so far is the 20844-85 at: https://deltrol-controls.com/sites/default/files/pdf/data-sheet/270-275 Series Data Sheet.pdf...
  17. flippineck

    Current transformer

    I have a small through-hole type current transformer https://docs.rs-online.com/93d6/0900766b8169af7d.pdf with a coil ratio of 2500:1 with a single pass of live 240V AC 6mm² conductor through the hole. If my calculations are correct, feeding the secondary across a 100Ω burden resistor should...
  18. flippineck

    Where to start

    I have some limited prior experience programming in the following, with best ability in the first languages and worst as you go down the list.. php perl BASIC javascript C 1980's PLC ladder logic Z80, 6502 assembly Ability level going from slightly sub-moderate down to slightly above poor...
  19. flippineck

    Load auto-detect

    This is in relation to an outbuilding with a small single-phase 240V AC ring main, fed by a diesel generator with a remote auto-start feature. I saw a device advertised which you attach to the ring, and to the generator's auto start signal input. From the advertising info, it seems it applies a...
  20. flippineck

    Retrofit house with LEDs

    Moved house, and found that a few rooms have a bunch of 12v incandescent halogen reflector bulbs fitted in the ceilings. Two rooms have six 35W lamps, another has five 35W lamps, another has 5 in it's ceiling. Have been going round replacing all these halogens with LED equivalents & so far...
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