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  1. Hero999

    Advanced Battery Technologies

    For the final time, stop bumping old threads!
  2. Hero999

    Power Supply for capacitor bank

    What open ends? There's only one which is the output and that's because I forgot to label it. U1 is an oscillator and performs exactly the same function as the 555 in your circuit, look up Schmitt trigger comparator oscillator on Google for more information. U2 is a comparator which shuts off...
  3. Hero999

    Electro Magnetic Pulse

    I would've thought stingers would be a more cost effective solution which have been in use for many years. Microwaves are just high frequency radio waves, typically >1GHz.
  4. Hero999

    Need help with circuit, willing to pay for full design!

    That circuit won't work. It's not a TRAIC, it's an SCR which is connected backwards and pin 2 of the 555 has no pull-up. It's pretty easy to make a monostable which is triggered by pressing a switch and is not retriggerable, using the standard 555 timer circuit and an AC coupling capacitor, the...
  5. Hero999

    A proposal for using ultrasonic wave bird flock repellents in aircraft

    Not all birds are dumb, some are as clever as chimps. A quote from Wikipedia: "Crows in urban Japan have innovated a technique to crack hard-shelled nuts by dropping them onto crosswalks and letting them be run over and cracked by cars. They then retrieve the cracked nuts when the cars are...
  6. Hero999

    Buck converter with SG3524 and IR2117, problem with duty cycle.

    Yes you've missed some information: the schematic. There should be no need to manually adjust the duty cycle, the SG3524 should do it automatically. The duty cycle should also depend on the load current and will generally be a bit higher than the calculations suggest because of the losses. The...
  7. Hero999

    Automatic Fan Controller - Help (w/ relay?) Please!

    The buzzer should work even if you used the LM393, sorry I didn't read the part about you saging 10mA, I only took notice of the 500mA written on the schematic. Yes, it needs to be a PNP transistor. It's possible to use a NPN transistor and short the base to 0V with the output of the...
  8. Hero999

    Automatic Fan Controller - Help (w/ relay?) Please!

    Neither of those circuits will work. The LM311 has an open collector output (see datasheet and internal schematic if this doesn't make any sense) this is why is why I used a PNP transistor. The LM311 has a maximum current rating of 50mA, not enough to drive a 500mA buzzer. Why not connect the...
  9. Hero999

    Power Supply for capacitor bank

    The LM393 can be configured as an oscillator so a 555 is not needed, here's an example. Two capacitor banks can easilly be connected in parallel.
  10. Hero999

    More PWM questions

    >80A is PWM pretty common in motor control circuits for small electric vehicles such as golf buggies. Large vehicles such as cars require surges of over 1kA but they normally uses AC motors rather than DC.
  11. Hero999

    questions about FM Superhetrodyne Receiver

    No. Look up  superheterodyne receiver and you'll see why the oscillator's frequency needs to be different to the signal being received that's all I'm going to say.
  12. Hero999

    circuits on another site linked to different circuits in electronics lab

    The problem is with that site, not Electronics Lab, some of the links are broken.
  13. Hero999

    A proposal for using ultrasonic wave bird flock repellents in aircraft

    Good, the original poster or a moderator unlokced the thread. This idea has many flaws: As audioguru said, aeroplanes are already very loud as it is, what makes you think that making them a bit louder would help scare off birds? To increase the sound level by 10dB (twice as loud, ten times...
  14. Hero999

    Make it impossible for non-moderators to lock their own threads.

    Someone made a thread asking a question but accidentally locked it so no one else could reply to it. This is bad because it could mean people could post something to annoy others, then whine and lock their own thread when they don't like what they say. To demonstrate this, I've locked this...
  15. Hero999

    LM338 Power Suply Current Regulator

    I don't know if your problem has been solved or not because I don't know what it is. It depends on whether you need current regulation or just current limiting. Adding another LM338 is fine, if you just want to limit the current but is no good for regulation. Note there is a big difference...
  16. Hero999

    Automatic Fan Controller - Help (w/ relay?) Please!

    Whoops, I've just noticed the circuit I posted contained a relay. Anyway, I hope you get the general idea. I drew the schematic for someone on another forum who wanted to switch a large relay which required >100mA so couldn't be directly controlled by the LM311.
  17. Hero999

    Automatic Fan Controller - Help (w/ relay?) Please!

    Nice work, I'm glad you've got it working. I notice the relay contacts are connected to+V, I wish you had said that you plan to power the fans off the same power supply as the temperature sensor. You could've replaced the relay with a transistor and a couple of resistors which is cheaper, more...
  18. Hero999

    LED Necklace

    It doesn't matter whether the pot is before or after the the capacitor. To alter both channels simultaneously you'll need a dual ganged pot, alternatively you can not bother and mix both channels together by using a 100R resistor for each signal. That's a clever little circuit but its output...
  19. Hero999

    Power Plugs

    I take it there's also a requirement for maximum/minimum force required to unplug the connector? I can't help you I'm afraid. I suggest you check the usual suppliers (mentioned above), then go somewhere a bit more specialist such as a pyrotechnics supplier, if you can't find anything.
  20. Hero999

    xray

    ?
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