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  1. kellys_eye

    Honeywell 5800 help please

    The sort of reply/content of your post is most welcome indeed - regardless of its potential usefulness! It is refreshing to read content from someone who has such knowledge and experience and is prepared to take the time to detail it as you have. <thumbs up>
  2. kellys_eye

    Looking for replacement Transformer

    If you could find out whether the AC is used 'as is' or is converted to DC you could then replace the whole transformer/rectifier/regulator section with an SMPS DC supply instead. It may well fit in the case!
  3. kellys_eye

    How to reconnect this tiny cable?

    You could still solder wire straight onto the board and use 'any' connector to make a removable connection. board ----wire---- (two pin plug socket of your choice) ----wire----where ever it goes!
  4. kellys_eye

    L46H1 Goodview

    Goodview? But I must say that the remote control for it looks suspiciously like any you get with cheap Chinese LCD photo display panels sold for $10....... quite possibly using the same technology but feeding the output to a standard TV display panel..... You could do worse than purchase a...
  5. kellys_eye

    Looking for replacement Transformer

    That's one fried transformer! Clearly the system is 'under-designed' and the lack of circuit protection is deplorable. I'd be inclined to find the aforementioned 12-0-12 transformer AND a separate 6V/1A transformer and fit them in an external case and use a wire/plug to power the station. I...
  6. kellys_eye

    eprom studys...

    First - most chip activation signals are 'active low'. In other words you need to take the signal line to logic 0 (ground) to enable them - chip enable and output enable are both 'active low'. Second - you cannot 'drive' LEDs from the output lines. You CAN connect an LED via a resistor and...
  7. kellys_eye

    Looking for a specific transformer

    If you know what DC voltage you need then look for a power supply that can provide that instead. It'll give you what you want irrespective of the way it does it!
  8. kellys_eye

    "Sharp" inverter a/c.

    One of these....?? Which one?
  9. kellys_eye

    Looking for a specific transformer

    30V AC - sure about that? What is the 'end voltage' going to be? If it was 12V then the circuit would have to DROP the other 18V and that could mean a lot of wasted energy (heat) and design problems. You really need to know the full parameters of the circuit you want before making any...
  10. kellys_eye

    Android tablet pcb

    Does any of the technical information you have show the parts placement? In its simplified form, the circuitry takes the battery volts and applies it via various SMPS devices to obtain all the required voltage rails used in the device - anywhere from 1.8V to 5V or 12V - a separate SMPS device...
  11. kellys_eye

    Looking for a specific transformer

    You have to calculate your NEED first - then work backwards, adding all the 'inefficiencies' on the way. You end up at the power INPUT requirement which is the 'size' of the transformer you require. Older transformers (the heavy, metal laminated versions) operate at the local supply frequency...
  12. kellys_eye

    Looking for a specific transformer

    What kind of battery? Either way, let's take a 12V battery as an example. 12V @30A is only 360 watts...... add losses and maybe 500W. There are a gazillion battery chargers on the market already. Many are cheap and sophisticated. Unless you have a notion of a new way to charge batteries -...
  13. kellys_eye

    Looking for a specific transformer

    ....and what would that dream be? If we knew what your 'dream' was we could suggest a suitable item.
  14. kellys_eye

    "Sharp" inverter a/c.

    Make? Model?
  15. kellys_eye

    How to reconnect this tiny cable?

    Is the connector absolutely necessary? If the item is intended for repeated dismantling then sure, fit a new connector but if this is a one-off repair that is unlikely to ever be dismantled again then just eliminate the connector and hardwire (solder) the wires where they are needed. Such...
  16. kellys_eye

    Power Supply Transformer Markings

    I concur with the above. The 'white' transformer is a common-mode choke - filtering the incoming supply. The 'black' transformer is the actual Switching one - it will have the usual primary (possibly centre-tapped), the secondaries - and there can be multiples of them and (possibly) a...
  17. kellys_eye

    Sencore TF46 Testing

    Have you got the operating manual for it? You can Google it and download one for free if you haven't got one.
  18. kellys_eye

    Cool the temperature inside a perspex box

    Use a peltier device https://www.amazon.co.uk/100W-TEC-Thermoelectric-Cooler-Peltier/dp/B007TPCEKI
  19. kellys_eye

    basic

    Do you have the complete equipment the board came from? You should be able to determine what the board is 'supposed' to do, identify the 'building blocks' of the board (its power supply section, its signal processing path, its output etc) and check them individually. The manufacturers MAY...
  20. kellys_eye

    eprom studys...

    'Generically' that's a simple 27C512 device which has 64k x 8-bit of EPROM. There will be 16 address lines and 8 data lines. The contents of any of the 64k (65536 actually) 8-bit registers will appear at the output according to the 'address' you select on the appropriate address lines...
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