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  1. Martaine2005

    Add one resistor to give bipolar LM555 oscillator a 50:50 duty cycle

    With all due respect, if you don’t understand what tolerance means, look it up. The data sheet states max, typ and min for many specs. Not one data sheet “on the planet” (your words), will give tolerances of third party components. These components WILL affect the real world tests. 1% to 20% can...
  2. Martaine2005

    Project design with minimum cost

    A one off project would be very expensive if designed solely (from scratch) for one customer. Coding, receiver design, components, PCB design and manufacture, safety and emissions compliance etc etc. Martin
  3. Martaine2005

    Project design with minimum cost

    Why bother? Plenty of proven apps in conjunction with home automation already exist. The receivers for lighting can be as cheap as £8. Are you coding a new app? Martin
  4. Martaine2005

    Add one resistor to give bipolar LM555 oscillator a 50:50 duty cycle

    Simulations and calculations will differ. Calculations don’t adhere to real world implementation of imperfect components. That’s a REAL reason for tolerances. That can be, ie 1% to 20% tolerance. Martin
  5. Martaine2005

    Add one resistor to give bipolar LM555 oscillator a 50:50 duty cycle

    The data sheet says “typical”, not set in stone. Nothing is perfect. You should know that. Martin
  6. Martaine2005

    How do you program the 10 digit alarm number to connect to police station ona CS-250 system

    Perhaps you could check the manual. Here is a link to it. I haven’t read it but hopefully it will help you. Martin
  7. Martaine2005

    B&W A7 no power - PSU repair help please

    Frustratingly, the forum doesn’t indicate size limits, just an error!. Guaranteed sizes seem to be approx 300KB. It would be nice if the forum owners actually replaced the ‘error’ message with a reason. “File too large, resize to …” But I guess that would be too easy?. Martin
  8. Martaine2005

    How do you program the 10 digit alarm number to connect to police station ona CS-250 system

    Is this an Airtech alarm?.
  9. Martaine2005

    Building a manually-controlled touch screen tapper for controlling farm tractor GPS

    Get yourself a cheap oscilloscope. Martin
  10. Martaine2005

    Swapping Out Boards, Repairing and the Economics Considerations Involved

    My go to app was an A to Z or Greater London map. Outside of Greater London, I’d buy a local map of the area from a petrol station. I’d still be able to get you there quicker than a satnav!. We have our marmite (black cabs) love m or hate em taxis. Once a gold mine, now a battle with Uber. I...
  11. Martaine2005

    Faulty Electronics and Ethical Practices

    Here in Fulham and South west London, the recycling centres are section by section. Metal, wood, hard plastics etc. I have never been questioned dumping one item and redeeming another. Albeit, not often. I am not a tramp or dirty old soul. But sometimes a little gem sparkles and calls my name...
  12. Martaine2005

    On a 3 led battery, yellow, Red, Black, how do i charge it

    Best advice ever. Martin
  13. Martaine2005

    For Sale: Several oscilloscopes for sale for parts

    ^ Same questions.
  14. Martaine2005

    Faulty Electronics and Ethical Practices

    Our recycling centre has sections for electronic items. TVs, radios, VCRs, Hi Fi etc. It all gets recycled. PCBs get stripped of copper from transformers and coils,. ICs, connectors etc for gold. And all the plastic for, well, plastic. Lots of goodies can be found in that section. I dumped a...
  15. Martaine2005

    Swapping Out Boards, Repairing and the Economics Considerations Involved

    True story: Two or three years ago, I was in the garden with my then 20 year old son, a lovely summers day. I was using my magnifying glass to read some tiny print when I told him about ants in the sun and a magnifying glass. About how as kids we used to torture the little pests. He laughed and...
  16. Martaine2005

    How to calculate my battery bank Ah ,kw and Kwh

    https://us.v-cdn.net/6024911/uploads/editor/cr/3dwynj1do6yl.jpg. This diagram may help the OP. Martin
  17. Martaine2005

    Micro-Lipo Charger

    Looks like it’s only a charger. Specifications don’t mention it will switch from charge to battery use. You can put your own switch in there to either charge the battery or power the device from the battery. Martin
  18. Martaine2005

    FSM - Can someone help me to solve this?

    Your state machine will require a micro controller. It’s obviously a traffic light or pedestrian light crossing. Using a counter IC, you could achieve the 2 second and 1 second intervals by jumping outputs. what have you done so far to map this out? Martin
  19. Martaine2005

    HAM Radio Relevance Currently and Personal Reflections.

    You can stream any music, any time but people still buy CDs or vinyl records. Hobbies don’t die. Some just love having a transceiver rather than SDR (software defined radio) on a computer. It’s a matter of a hobby and a preference to real working equipment that can be honed, tweaked, repaired...
  20. Martaine2005

    I think I got abducted...

    It’s ET phoning home. Martin
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