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  1. Alec_t

    How to monitor a battery for a Raspberry Pi drone?

    That should work. But the battery voltage alone won't be a good guide as to how much useful charge remains. A 'Coulomb-counter' is more effective.
  2. Alec_t

    Can an 74AUP1G06 Inverter drive an LED?

    Yes, if the assembly and its voltage supplies were correct. Run a simulation. Build a prototype (even on a breadboard) and get that working before submitting for manufacture.
  3. Alec_t

    Can an 74AUP1G06 Inverter drive an LED?

    It is rarely a good idea to run components at their maximum ratings. That LED should give adequate brightness at much less than 20mA current. In your posted circuit Vcc = 3.3V, R23 = 560R. From the D9 datasheet, Vfwd = 2.05V minimum @ 20mA. So the maximum D9 current is ~(3.3V-2.05V)/560R =...
  4. Alec_t

    Can an 74AUP1G06 Inverter drive an LED?

    It should work IF the LED current you need is less than the current the inverter can provide without exceeding its rated maximum and without its output dropping below the Vfwd of the LED. Have you checked the inverter's datasheet?
  5. Alec_t

    Can anyone help me please for this

    Welcome to maker.pro. Brand/model? What markings (if any) are on the clock case? Did/does it have a mains plug or battery contacts? Unless you know where the 5 wire ends in pic 4 are supposed to connect there's not much chance of getting the clock working.
  6. Alec_t

    Hardware issues

    Welcome to maker.pro. 1) It might well do, depending on what the pin functions are and what the maximum allowable pin currents and voltages are. 2) Depends on the board design. Voltage where? Current through what?
  7. Alec_t

    Basic transistor switch

    The circuit in post #1 should be fine, unless the load is inductive. If that's the case then there should be a reverse-biased diode connected across the load to suppress any back-emf voltage spike.
  8. Alec_t

    doubt batteries storage

    ~60% of full charge is the recommended storage condition. Ask the manufacturer what the corresponding voltage and recommended temperature are.
  9. Alec_t

    Installing reverse switch, wires get hot from power source

    The teeth on a band-saw blade are shaped to cut in one direction. Why would you want to reverse that?
  10. Alec_t

    Constant current circuit

    R14 is a current sense shunt. The voltage across it (proportional to current) is buffered by U2B and sensed by the micro at pin AN11. In response, the micro adjusts its output voltage on DAC1OUT. This is conditioned by U2A which drives the MOSFET gate to whatever voltage is needed to keep the...
  11. Alec_t

    Does anyone know the pneumatic equivalent of an electrical capacitor?

    The exhaust muffler for a car is just that. The perforated baffles provide gas flow resistance and the chambers beyond provide the equvalent of capacitors.
  12. Alec_t

    Is there any way to invert low voltage AC to higher voltage DC?

    Shouting into a microphone isn't going to have anywhere near enough energy to charge a Li_ion battery (other than a microscopic one) in any reasonable time :(. Current and voltage are both important. For a given amount of input energy, raising the voltage will be at the expense of lowering the...
  13. Alec_t

    Trouble converting from battery power to DC adapter

    What sort of light? Incandescent or LED? If incandescent then the surge current at power up may exceed the output capability of the adapter, resulting in it shutting down.
  14. Alec_t

    how to go from one power source to many power sources

    It shows that two loads can be driven in parallel by one power supply. The scientific world will be amazed! :)
  15. Alec_t

    how to go from one power source to many power sources

    Deleted
  16. Alec_t

    Help needed

    1300mAh is charge (current x time), not current.
  17. Alec_t

    BJT NPN + PNP to switch channel.

    Right.
  18. Alec_t

    Power suppy dilemma

    Your meter in post #5 is showing 0.275A, not 0.2A. So 4 LEDs should draw 1.1A at 5V.
  19. Alec_t

    BJT NPN + PNP to switch channel.

    The Arduino's rated maximum output current is only 40mA per analog/digital pin. An 8 Ohm speaker will draw as much as 625mA from a 5V supply, so will kill (or at least stress) the Arduino. A speaker is inductive and can generate damaging voltage spikes if switched off quickly. A speaker if...
  20. Alec_t

    Looking for more help with my electronic ‘bagpipe’ project...

    Well, we're not psychic so didn't know what other modules you intended to build and power with those supplies. Perhaps you're thinking of adding further tone generators to simulate the massed pipe bands of the Royal Edinburgh Tattoo ? :) :)
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