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  1. Alec_t

    Current Amplification

    Welcome to EP! As this is a Homework question, show us your best efforts so far at a design, then we can give guidance.
  2. Alec_t

    sound patterns

    A retriggerable monostable could be used to replace the 10mS burst with a single pulse. You've described one sound pattern. What are the others like, that you have to distinguish?
  3. Alec_t

    Need Advice: Software to Read an IC

    Welcome to EP! Sorry I can't suggest any software, but I'm curious as to how, even if you could read bytes from the IC, you would go about finding which ones define the address/data/program? Any internal program is proprietary and likely to be encrypted or otherwise protected.
  4. Alec_t

    Piezo sensor circuit

    The piezo effectively is a capacitor. Might be an idea to mount the piezo via a slightly resilient layer, not directly on the target plate. The piezo material is brittle.
  5. Alec_t

    Piezo sensor circuit

    Yup.
  6. Alec_t

    It came to me in a dream

    I think you need to add flux capacitors across the transistor junctions, otherwise the time differential will become unstable. E-bay will probably list some in the future.
  7. Alec_t

    Buzzer Help

    Personally I'd use a CMOS Schmitt trigger, instead of a differentiator, to get sharp pulse edges.
  8. Alec_t

    Buzzer Help

    Not unless you want 20mA flowing through the zener. The buzzer current is irrelevant. Make R=(30-3.3)/Izener. A zener current of just a few mA should be enough.
  9. Alec_t

    Piezo sensor circuit

    You will need to protect the opamp inputs from high voltage spikes. Diodes from R2 to both supply rails will help. D1 is unnecessary as the piezo generates a bipolar pulse. The non-inverting input of the opamp may need to be biased to a level close to that of the inverting input. Personally I'd...
  10. Alec_t

    Would like some advice about my motor speed control circuit.

    Should be fine.
  11. Alec_t

    4066 switches leaking in sample and hold circuit?

    All inputs of CMOS circuits need to be connected to something, not left floating, or you'll get weird results. An unconnected input will probably act as an antenna and pick up all sorts of interference which can cause havoc.
  12. Alec_t

    Question

    Welcome to EP! As you have identified neither the manufacturer nor the model of any of the instruments there is no unique answer. When you know the makes and models, check their datasheets.
  13. Alec_t

    not starting bldc motor

    The PWM from the micro is a series of logic-level pulses, but applying them to AND gates (I assume you are now referring to those in the post #4 .png circuit) won't necessarily give the non-overlapping relationship needed to give a dead-time when neither the high-side nor the low-side FET is on...
  14. Alec_t

    child safety in cars

    Welcome to EP! The main item you will need is a CO2 sensor module. One with an analogue output might be simplest to interface with the car's electrics, but you would have to understand the car's wiring system. With so much done digitally in cars these days, a digital interface could be required...
  15. Alec_t

    not starting bldc motor

    Set up the circuit as shown, connect a 12V rated incandescent lamp as a dummy load, connect +12V to +Vdd, +Vcc and +MOSV, apply logic-level pulses of several kHz repetition frequency to HIN and LIN, vary the mark/space ratio of the pulses and see the effect on lamp brightness. Note: HIN and LIN...
  16. Alec_t

    optical character reader and scanner

    This machine seems to be a self-contained example So the answer is "yes"..
  17. Alec_t

    CDI ignition head scratcher

    Should the 27V winding produce an AC voltage or a DC one? If AC, then I doubt using a battery as suggested would work. Could a DC input harm that box of tricks with the indicators on it?
  18. Alec_t

    not starting bldc motor

    Do you mean the right-hand circuit attached to post #4, or just the IC itself?
  19. Alec_t

    Satellite detection

    Satellite finders work on the principle of determining a dish position which gives maximum received signal strength. To identify that position involves moving the dish methodically from one angular side of maximum to the other side, in both elevation and azimuth. So if you want a system which...
  20. Alec_t

    not starting bldc motor

    ... may get you almost an answer. Trouble-shooting without the exact circuit you are using will be only guesswork.
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