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  1. Alec_t

    USB power cable with 35 second delay

    From the advertiser's write-up for that AT41 timer, I don't think it will quite do what you want. Pins 5,6 can be jumpered to configure it to be initially ON until triggered, then OFF for a pre-set period, then back ON. It's that initial ON which you don't want. It's not known if it can be...
  2. Alec_t

    Artificial Intelligence

    It is already being used to replace call centre staff by chatbots and has potential to replace staff in many professions where trained/expert opinion is required. If too many employees lose their jobs there is likely to be civil unrest. If that escalated to riots there could well be a threat to...
  3. Alec_t

    Nail electromagnet to repel button magnet.

    Those little neo magnets are pretty strong. I'd guess you will need many turns of magnet wire and a hefty current to be able to drop it off the nail. Have you considered any alternative approaches, e.g a micro servo to release a catch, or a thermally-released bi-metal catch?
  4. Alec_t

    DC voltage reduction circuit needed

    There are loads of DC-DC converters advertised online. Won't one of those do, if bought from a reputable source? No guarantee it'd be bullet-proof though.
  5. Alec_t

    Will get pulsating DC on a transformer's secondary if I apply pulsating DC to it's primary?

    It is likely the transformer core saturated, so the primary coil inductance dropped, so the coil drew a lot more current than it was rated for.
  6. Alec_t

    Timer circuit

    Hi AK, I see you had the same problem with the forum's 'helpful' software as I had! I have reported it.
  7. Alec_t

    Weird coil latching problem

    CR6 certainly looks blown. K1 doesn't look very happy either.
  8. Alec_t

    Problems with my school project Automatic ON OFF lamp using LDR and MOSFET

    Welcome to maker.pro, but I agree with Harald.:eek: Because R10(?) prevents any significant current flow in the circuit. What is the lamp rating? Which MOSFET? What are the LDR specs?
  9. Alec_t

    Timer circuit

    @HomerDodd Perhaps this analogy will help, where heat energy is analogous to money :- Consider you're a worker being paid£50 per hour to work an 8-hour day on a project. Which gives you more, (a) being handed £50 every hour or (b) £100 every 2 hours or (c) £200 every 4 hours or (d) £400 each day?
  10. Alec_t

    Timer circuit

    I wonder what it would feel like, swimming in a pool of superfluid?
  11. Alec_t

    Timer circuit

    I don't see how using a timer will help. If you slow down the average flow rate by a factor of 3, 4, or 5 as per post#1 then the pool will, of course, take proportionally longer to heat up to the required temperature. The total heat energy added to the pool over that longer period will be the...
  12. Alec_t

    The output of IR2104 is not square wave, Ho and Lo are not square wave. When Ho is high, then Lo is also high.

    Why is your scope connected to LO rather than Gnd?
  13. Alec_t

    Check individual cells of a car battery.

    If you found a shorted one, is there any DIY remedy?
  14. Alec_t

    Op-Amp voltage follower output different from input

    Leaving input pins 12 and 13 floating is not a good idea. It could lead to unpredictable effects, such as oscillation.
  15. Alec_t

    Why Does My iPhone Overheat and How Can I Resolve It?

    Perhaps your phone's battery has developed a fault?
  16. Alec_t

    Circuit from "Watch Winder" doesn't turn on the motors.

    Well, if the 12V got through to the board, which is rated for 3V/9V, then no surprise that it no longer works. If the IC type is a mystery and can't be deduced by reverse-engineering, there's virtually zero chance of repairing the board.
  17. Alec_t

    Circuit from "Watch Winder" doesn't turn on the motors.

    Looks to me as though the board needs both a 3V supply and a 9V supply. If it's possible to plug those into the wrong board sockets and the IC got 9V instead of an expected 3V then that could explain the failure.
  18. Alec_t

    Can I replace L78MS05 5ZVW with L78MS05 6SWN

    Welcome to maker.pro. Those 'remaining numbers' identify different case styles/mountings, e.g. through-hole or surface mount. The style/mounting affects heat dissipation and hence power handling ability. You would need to check datasheets to identify which variant is appropriate for your use.
  19. Alec_t

    want to use Headphones and main speaker

    If so, then it looks as though it would mean tapping into the Front R and L speaker connections and applying the signals via variable attenuators to the headphones. I haven't checked if there is any module already available online to do this.
  20. Alec_t

    want to use Headphones and main speaker

    Welcome to maker.pro. What audio output sockets are available on the system?
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