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  1. dave9

    HOW DO I SHIELD MYSELF FROM A NEIGHBOURS SMART METER?

    Tin Foil Hat :D Kidding aside, the field generated from one of those, IF it even escapes the (presumably metal) box it's in, is nowhere near strong enough to be harmful from a distance. You're in much greater danger from the electronics in your own home, like that computer or phone you used...
  2. dave9

    heated jacket

    lol... " Pull resistance. Cannon be broken. " Sometimes I am amazed at the amount of components in the build for something cheap-from-China, so I could be wrong, but at this price point I am doubting that it has much in the way of regulated current in that little power button box, and yet it...
  3. dave9

    What connector is this?

    Either get a socket that matches the PSU you have, or pick a matching pair so you put a new one in the dock and a new plug on the PSU, OR buy a new PSU and pick a socket that matches it, OR buy a new PSU and replace the socket and put a new plug on it too. Where to get them would be a UK...
  4. dave9

    PWM setup

    ^ In the following post he mentioned 660nm red LEDs, which should be around 2.0Vf. https://www.electronicspoint.com/threads/pwm-setup.289465/#post-1774462
  5. dave9

    PWM setup

    It won't exceed the power rating because although the LEDs are rated up to 3W, the driver is 1W so ~ 330mA-ish. That's how I'd do it too, under drive the LEDs for more efficiency and brightness per watt, plus easing the heatsink requirement by reducing per die thermal density, at least in a...
  6. dave9

    integrated battery charger

    The question is why you need this, what you plan to put it in, why you can't just use a standard USB charger product? It doesn't eliminate needing a power supply in front of it and that PSU could just be a regulated 5V. Remember the products themselves have charge controllers in them. Also...
  7. dave9

    PWM setup

    Might have trouble regulating as it's spec'd for output of 7 to 12 LEDs, 20V to 42V while your 4 LEDs aren't dropping 20V across them.
  8. dave9

    Casio Privia Px330 Piano Keyboard power adapter input

    It looks fairly standard except that the square portion of the jack right behind the circular portion that sticks out of the chassis, would butt up against the chassis to provide strain relief to some extent. Look at the back of the circuit board to see if the solder joints (and possibly copper...
  9. dave9

    Flashing LED problem

    Wire the LED with a series resistor to the amp positive power rail and ground. If the switch LED has a built-in resistor to get the appropriate current from a 5V supply, approximate the forward drop of the LED based on its color, measure it's current draw from 5V, to approximate the resistor...
  10. dave9

    integrated battery charger

    I don't understand a reason or purpose for what you're suggesting. You'd need a bulk power source anyway in order to have a higher DC voltage to drop voltage down to 5V with LM7805 but LM7805 is a lossy, low efficiency linear regulator so that makes your bulk power source need be all that much...
  11. dave9

    Resistor Value

    Maybe we need to back up a bit. Why did you remove it? I assume the PSU has failed? Did you probe it with a meter, measure voltage coming from the bridge rectifier and find none after this component, OR it blows the fuse immediately when turned on? If so the fuse blowing is "most likely" a...
  12. dave9

    integrated battery charger

    The devices have their own charge circuit, only needing the same voltage and sufficient current supply as specified (or included with the product). All such devices that use Li-Ion batteries must have this to protect themselves and the rest of the world from battery damage which can result in...
  13. dave9

    Painting own 6mm guitar/instrument cable 6mm

    If they are vinyl insulated then I would use spray vinyl dye from an automotive store. It seeps into the vinyl so it's more resistant to cracking and peeling. You do have to settle for whatever colors you can find as it is not typically available in every color of the rainbow. Common colors...
  14. dave9

    2N2222A

    Allow me to help you, help us, help you, with a suggestion. You could lookup their datasheets, link to them, and list the relevant parameters your circuit needs. The datasheets will also picture the pinouts.
  15. dave9

    Does mAh rating of a battery affect the device at the same rated voltage?

    ^ It may be somewhat of a nitpick in this particular case. These phones most likely use a crude trickle charger, a wall wart (wall plug AC/DC adapter) somewhere between 6VDC and 12VDC, then a resistor in series to charge 3 x AAA series cells.
  16. dave9

    Resistor Value

    It looks intact to me, like it should give you a valid resistance measurement if it's a resistor so you don't need the color bands. However that wavy shape to the body of it, does look like it may be a wire wound inductor. Similarly, it looks intact to me so are you assuming it's bad and...
  17. dave9

    how to make the circuit of a wall e robot

    Were you looking to spend $5000 for this design or the $20000 deluxe version?
  18. dave9

    Power supply for 1960s movie projector

    Now the adventure begins! You can convert it to LED. :p Just kidding.
  19. dave9

    Premier PHP2026 Massage Chair Repair

    Might be a silly question but have you tried the chain with a different wall outlet? Maybe yours with USB was generic Chinese junk (just a guess)? Otherwise, what does "I get now is an ER on the remote" mean? What does the manual state ER means? If it just means error, I'd guess you probably...
  20. dave9

    Power supply for 1960s movie projector

    The following page suggests it can use 100 to 240VAC, 50/60Hz, so If That's True you should merely need a cord that fits both your outlet and the projector, or to cut and graft together a cord you have with the correct wall plug, and that cord with the correct projector plug...
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