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  1. C

    Electronic Swing Device

    There are pendulum clocks, nodding heads and tick-tock mechanisms on eBay using the magnet and coil principle.
  2. C

    How to work with Zener diodes?

    "Your diode requires 20 mA to produce 2.4 Volts, " That is not true AT ALL. The minimum current to keep a zener in breakdown depends on the wattage of the zener. A 400mW zener requires much less current than a 2 watt zener. The minimum current through a zener needs to be about 5mA for a 400mW...
  3. C

    74HC14 Schmitt Trigger

    Generally, with a Schmitt Trigger, it does not matter if the inputs are left floating because the hysteresis is about 30% of supply and gates will not self-oscillate. Tieing them HIGH or LOW does not affect the quiescent consumption.
  4. C

    Need a 555 cct that can only be triggered once during its countdown time

    It's either a solenoid and plunger or a timed COB module. Neither need a timed input.
  5. C

    Need a 555 cct that can only be triggered once during its countdown time

    " but Dave wanted to use a 555 timer." There is no point in using a 555 when it is not needed. "your circuit will require a small delay so the bell is on for long enough initially." That is NOT how a ding dong bell works.
  6. C

    Load on Power Relay Causing Microcontroller Reset

    Just add 100R to the PIC chip. It does not need 5v.
  7. C

    Using pnp and npn transistor as 1 pole 2 throws switch

    Just do this:
  8. C

    Need a 555 cct that can only be triggered once during its countdown time

    Here is a much simpler circuit that takes no standing current.
  9. C

    How do I increase energy flowing into a Capacitor?

    330v AC is more than 400v DC when rectified.
  10. C

    Trying to replace resistor on a remote keyless gate access panel.

    R16 is not 16 ohms. Get a multimeter and read across the resistor. If it is open, read from one end to as far as you can go along the spiral.Do the same for the other end and add the resistances.
  11. C

    Driving a led from high-voltage source

    This is a very simple application. You just need a capacitor, zener, diode and a few other components.
  12. C

    Need some coaching,not sure where to start (KVL)

    Start by removing the 5v and put 295v as the supply. Now we have a 211 ohm resistor with 47.5mA flowing through it. Work out the voltage that will be developed this resistor. Now take this voltage off the supply voltage of 295v = X For the left-hand path we have 21.4k plus 9.74k in series and...
  13. C

    Need some coaching,not sure where to start (KVL)

    This is not a basic electronics question.
  14. C

    Helping me get started

    Firstly buy a "luggage Alert" http://www.ebay.com/itm/Anti-lost-Bag-Luggage-Protector-Anti-theft-Alarm-Ring-Vibration-Remind-Black-/251929993504?pt=LH_DefaultDomain_0&var=&hash=item3aa832a120 and take the output to a brake.
  15. C

    Transformer

    Any transformer you cannot hold will start to smell and its life will be very short.
  16. C

    connecting LEDs in series

    Provide evidence of exactly what type of LED you are using. You can make a BIG mistake.
  17. C

    Capacitors

    "Even with that arrangement, the capacitor is prevented from complete discharge." Who said anything about fully discharging the capacitor ??????
  18. C

    Capacitors

    Here is the circuit:
  19. C

    Help with a LED driver

    The reverse voltage does not come into any of the calculations. It simply means that if you connect the LED around the wrong way to a voltage higher than 5v, the LED will or may be damaged.
  20. C

    Capacitors

    I have a circuit that dumps a fully charged capacitor to a battery.
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