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  1. Alec_t

    Charging Led Circuit

    If the red LED is on before you switch on the vac then it will be drawing current continuously in standby and flatten the battery.
  2. Alec_t

    Servo control of Outboard Motor Gearshift with 3 Switches

    Welcome to EP! An interesting scheme, but quite a challenge even for seasoned hobbyists. Do you have mechanical engineering skills and facilities? Do you have any experience in building electronic gadgets?
  3. Alec_t

    Simple (?) Bluetooth/Relay/Android App project

    Welcome to EP! We will need more info before we can even begin to give you pointers. For example, what is "low voltage", what is the solenoid current draw, what is "a position indicator with 1 digital output, 2 digital inputs", "low cost", "small size"?
  4. Alec_t

    Need help with a MOSFET npn type device

    Why a 10Ω shunt? That will drop 5V at 500mA and waste 2.5W of power. You will need to be careful in your choice of MOSFET to ensure it is switched fully on with a gate voltage as low as 3V.
  5. Alec_t

    Best Ideas for a DC Powered Motor Rod Rotator

    Welcome to EP! I was going to suggest the turntable drive from an old microwave cooker, but just noticed you specified DC-powered. Geared DC motors are available.
  6. Alec_t

    Help with Scintillator Circuit

    You lose the 'analog flavor' as soon as the signal gets amplified. I think the best place to tap off would be the base of the first transistor of the amplifier, i.e the R80/CR93 point. That should give you a signal with ~ 1V peak-to-peak amplitude. Whether or not the signal is in the audio range...
  7. Alec_t

    Help with Scintillator Circuit

    Welcome to EP! Depends what you mean by facsimile. As far as I can tell the PM output signal is a ~1.5kV negative pulse with a steep leading edge and a less steep trailing edge. The resulting signal at the inverting input of the comparator is a ~4V rectangular pulse (going from ~ -1.3V to ~...
  8. Alec_t

    Help with a mini sump pump with water sensor

    Welcome to EP. The buzzer in the alarm probably has a terminal permanently connected to either the -ve or +ve terminal of the battery. It would help us to know which one, so that a suitable point to take off a control signal for the pump can be identified. Do you have a multimeter to determine...
  9. Alec_t

    MC34071

    Here's a DIP one which might suit, but the max supply voltage (40V) would be rather marginal.
  10. Alec_t

    Color Sensor

    Yes. What I'd probably do is put the light sensor in a housing mounted right over the LED so as to exclude all extraneous light. That of course would prevent the user seeing the LED, so I'd then use the sensor signal to light another LED visible to the user.
  11. Alec_t

    Anemometer switch

    You might have to introduce a time delay of seconds/minutes/hours, depending on the speed at which the actuators move. You wouldn't want them opening/shutting too frequently.
  12. Alec_t

    Toro leaf blower motor

    Nice job. Pity the motor wasn't fitted originally with ball bearings.
  13. Alec_t

    Bosch Washing Machine

    Welcome to EP. Which Bosch Model?
  14. Alec_t

    Headphones - only hear from one side, volume wheel changes which

    Welcome to EP. Sounds like a bad connection or worn-out tracks inside the control. If the control has at some time been forced past an end stop then the wiper(s) could have been bent. Any chance of opening up the control to check inside?
  15. Alec_t

    Cruise control for fly by wire motorcycle

    I don't like to be a party-pooper but ...... Have you checked with your insurer that your policy won't be invalidated by a modification such as this? Are you willing to trust your life (and the lives of others) to a home-brew circuit designed by a bunch of unknowns on a forum? If the circuit...
  16. Alec_t

    Odd interference between electric heater and computer

    Interference from switch sparking, inductive back-emf, or voltage spikes on the mains, is presumably reaching some critical USB-related part of the PC via the mains led or via the cable of a mouse or other peripheral device.
  17. Alec_t

    Tiny motor for a LED Projection

    Welcome to EP. Waste of time putting foil/reflector behind the LED: all light is emitted forward. You will need a lens in front of the LED to project the image. The smallest readily/cheaply obtainable motor is probably one as used to vibrate a phone. But it would require a lot of gearing down if...
  18. Alec_t

    Controlling a simple DC brushed motor by PWM

    Don't forget to allow the motor to come to a halt before reversing it, or something could get damaged.
  19. Alec_t

    Color Sensor

    A photo-transistor or light-dependent-resistor in direct contact with the LED could exclude extraneous light easily, but presumably the LED has to be visible also to a human when the device is in use?
  20. Alec_t

    Controlling a simple DC brushed motor by PWM

    Do you need to reverse the motor or just control its speed? If reversal is required then things get more complicated.
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