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  1. Alec_t

    Help with open collector output

    Good to know it's working now.
  2. Alec_t

    Simple power supply?

    Perhaps the VR is oscillating? Try connecting a 0.1uF cap directly between the VR input pin and ground, as close to the input pin as possible (as per the datasheet).
  3. Alec_t

    How to make a capacitive power supply for 1W LED

    Capacitive power supplies are potentially LETHAL. Use an isolated supply (transformer-based or SMPS).
  4. Alec_t

    Activate transistor with piezo disc

    Is your 9V battery a reputable brand and fresh? If so, check the current draw of your circuit; it may be excessive.
  5. Alec_t

    internet

    Switch ISP? Move house?
  6. Alec_t

    Activate transistor with piezo disc

    C6 is charged/discharged by the 555, not controlled by the white noise. A dying battery will not be able to power the LM386 amp properly.
  7. Alec_t

    Adding LED lights to Kid Battery powerd Ride-on

    Yeah, I cheated there :). It's in the 'Misc' folder.
  8. Alec_t

    Beginner ... ferrite core coil for crystal set

    This article might help with the coil-winding; at least to give some ball-park figures for number of turns.
  9. Alec_t

    Adding LED lights to Kid Battery powerd Ride-on

    I just used the LTspice 'Edit/Draw' tool, having first set the line style to continuous and unticked the 'Tools/Drafting options/Orthogonal snap wires' tick-box.
  10. Alec_t

    Help with open collector output

    In that case I'm puzzled as to why you found only 3V between the V+ and output terminals when the receiver was activated :confused:. A 3V relay may not be suitable. I'm further puzzled by this bit of the receiver datasheet "Outputs:- Open Collector: Mosfet output maximum-switching 2Amps/40VDC"...
  11. Alec_t

    Adding LED lights to Kid Battery powerd Ride-on

    Here's how I'd wire it
  12. Alec_t

    Help with open collector output

    If you use a relay, don't forget the reverse-biased freewheel diode across its coil to protect the receiver from back-emf spikes! The relay pull-in coil current would have to be within the rated output capability of the receiver.
  13. Alec_t

    Simple timer

    Welcome to EP! I query whether you actually need a timer? The pump is unlikely to appreciate running dry, so would ideally be switched off when the bucket is empty. That would require an upper-level switch , a lower-level switch and a latching drive circuit for the pump.
  14. Alec_t

    motor driver 12v .. 2a... fail~

    Possibly. It depends whether the TIP147 fails open-circuit or short-circuit.
  15. Alec_t

    Help with open collector output

    When the open collector output is active it provides a low-impedance path to Gnd (conversely, a high impedance when inactive). How you use that depends on the current the output can sink (your datasheet or spec should tell you) and how much stall current the motor draws (usually a lot more than...
  16. Alec_t

    Adding LED lights to Kid Battery powerd Ride-on

    No. A string = 2 white + 1 red. There would be 2 strings, hence 2 regulators.
  17. Alec_t

    motor driver 12v .. 2a... fail~

    Your motor probably has a starting current well above 5A, so not surprising your power supply blinks. If R1 = 320Ω, the maximum setting (2k) of the pot R2 will give an output voltage of ~ 9V. That means the motor is under-powered and will start slowly, prolonging the time at which it draws a lot...
  18. Alec_t

    Trouble with solder

    I've never used the stuff, but it's said to be trickier to get a good joint with that.
  19. Alec_t

    Help Coming up with how I can do this

    If you're into programming, then how about mount a camera above the table and use some very sophisticated image-recognition software to track the objects?
  20. Alec_t

    Adding LED lights to Kid Battery powerd Ride-on

    If you go with 12V, then you need 2 strings of 3 LEDs. Each string needs its own current regulator. If you use a boost converter to get, say, 20V or so, then that could drive a single string of 6 LEDs and so need only one regulator.
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