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  1. Alec_t

    SPICE alive

    Which Spice version? Many regulars on the forums use LTspice (a free download from Linear Technology).
  2. Alec_t

    Want to make an Electromyography amplifier circuit.

    If DC is present it gets amplified along with the AC of interest. With any significant gain the DC will drive the output hard against either power rail. That prevents the AC giving any useful output.
  3. Alec_t

    Bi-directional Motor with speed control circuit

    You could avoid relays altogether by using a double-pole ON-OFF-ON toggle switch.
  4. Alec_t

    Want to make an Electromyography amplifier circuit.

    I would consider raising all the resistor values around the TL072 opamps by at least an order of magnitude, to reduce power consumption.
  5. Alec_t

    Bi-directional Motor with speed control circuit

    With Relay1 contacts as shown, the 555 supply is shorted to ground, so the 555 won't then function. Although the relay coils should connect to Vcc the contacts shouldn't. They should instead connect to the 555 output pin. You should add reverse-biased diodes across the relay coils (unless they...
  6. Alec_t

    Getting Feedback on Flow Sensor

    Welcome to EP! You don't have a ground connection going anywhere useful. What is the flow sensor spec? Datasheet?
  7. Alec_t

    Super bright led light

    Super bright LEDs are directional. Sounds like you need a 360º spread of light. Can't you just replace the red lamp?
  8. Alec_t

    Micro USB port pulled off

    I've no idea who does electronic equipment repairs near you in Egypt. These people might know.
  9. Alec_t

    Lamp Replacement on Equalizer

    If you get a replacement filament bulb, I'd suggest wiring a low value resistor in series with it to prolong its life without significantly reducing the brightness.
  10. Alec_t

    Garment Steamer

    Is the heater element for providing dry heat (unlikely), or is it the steam-generator element?
  11. Alec_t

    Micro USB port pulled off

    That depends a lot on your skills. You would have to dismantle the wheel (is it screwed or bonded together?), identify which USB wire/circuit-trace goes where, unsolder the damaged socket, then solder the wires/traces (extended if necessary) to a new socket.
  12. Alec_t

    Lamp Replacement on Equalizer

    One thing to consider with LEDs is beam angle. They are usually quite directional, whereas a filament bulb has a broad spread of light. So you may well need either a LED array or an effective light reflector/diffuser.
  13. Alec_t

    Alternate iPhone charger design

    Welcome to EP! The circuit is presumably copyrighted, patented or otherwise protected as Intellectual Property (IP), so you would need to get the IP rights holder's permission to go into production. The circuit as is does not have the resistors defining specific voltages on the USB data lines...
  14. Alec_t

    9volt battery

    Not understood. Is there space in the guitar to accommodate a pack of six AA-size (or larger) cells?
  15. Alec_t

    9volt battery

    1A is a helluva current for something intended to run from a 9V battery. What exactly does the battery power? A pickup preamp, an amplifier with a loudspeaker, or just a headphone amplifier?
  16. Alec_t

    Voltage Controlled Voltage Source (VCVS) - Piezo Buzzer

    O.k. So PWM* could be used after all (per post #9), in combination with the mode selection (per post #11). Edit: Filtered PWM.
  17. Alec_t

    Voltage Controlled Voltage Source (VCVS) - Piezo Buzzer

    Aarghhh, I missed that :oops:. Good catch. So, three digital outputs suitably driven, plus some 1A rated output transistors (BJT or MOSFET), plus a couple of diodes will do the trick, and PWM isn't suitable.
  18. Alec_t

    Voltage Controlled Voltage Source (VCVS) - Piezo Buzzer

    Here's an option for PWM control. The blue trace represents PWM duty cycle.
  19. Alec_t

    Getting ready to manufacture something and need advice for detachable battery pack.

    How will you waterproof the USB socket?
  20. Alec_t

    Homework help!

    If you check the online catalogue of any major electronics components distributor (such as Farnell, Digikey, Mouser, RadioSpares etc) you will see the various parameters/units used for selecting/characterising components.
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