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  1. Hero999

    IR Switch for LED

    Here's my idea. The LED current is 11mA but it's pulsed at 10% duty cycle at just under 1Hz. The emitter current is 40mA and pulses at about 1% duty, (I didn't bother calculating the frequency, ballpark 100Hz). Note that two gates have been connected in parallel because each one is only...
  2. Hero999

    Importance of resistor values

    It depends on what the resistor does. If it's something like a a current limiting resistor in series with an LED or transistor's base then it's not critical so you can go 10% either way but if it's in a potential divider which determines the output voltage of a regulator, such as the LM317...
  3. Hero999

    IR Switch for LED

    If depends on the day length and light intensity on the shortest darkest winter day and the size of the panel. I suppose you could put the  IR sensor in a position where it receives daylight it'll save power by not working when it's not used during the day. I have an idea of how it can be done...
  4. Hero999

    Electronic suppliers

    Where do you live? Here in the UK I use RS Components (not to be confused with RadioShaft), Farnell and Rapid Electronics.
  5. Hero999

    IR Switch for LED

    Thinking about this more, you'll never get that kind of battery life from AA cells. Your circuit draws 150mA continuously and the flashing LED draws 35mA pulses at presumably 50% duty cycle making the average current draw 150+35/2 = 167.5mA. http://data.energizer.com/PDFs/l91.pdf A standard...
  6. Hero999

    New member!

    Hi, welcome to the forum.
  7. Hero999

    Roms for N64oid

    You could try illegally downloading them from a bittorrent site.
  8. Hero999

    IR Switch for LED

    RD doesn't draw much current so is immaterial. You won't be able to get that kind of battery life at a reasonable brightness from AAA cells.The only way is to use a CMOS oscillator to flash the LED for 0.1s per second (10% duty cycle) but not with a flashing LED which will flash at 50% duty cycle.
  9. Hero999

    IR Switch for LED

    The second circuit is still wrong. My comments below only refer to the first circuit which will work. RB isn't required because RD will limit the current through the transistor's base. The values for emitter and LED current given on the data sheet are maximum ratings and it continuous...
  10. Hero999

    IR Switch for LED

    The first schematic won't work because the emitter and detector are connected backwards. The second schematic is even worse because all the components are connected backwards.
  11. Hero999

    accelerometer

    It looks like Filipino to me.
  12. Hero999

    Solar project in Peru

    You can any voltage solar pannels you like as long as you can buy a suitable grid tie inverter. As a general rule of thumb, it's better to use higher voltages because the current will be lower so you can use thinner cheaper cables. Of course though, higher vottages are more dangerous. With DC...
  13. Hero999

    Water Level Indicator

    Yes, it's annoying when that happens which is why I generally write no more than a couple of lines for the first response to a thread like this. In this case I posted the schematic for your benefit as much as anyone else's.
  14. Hero999

    Water Level Indicator

    Yes, the capacitors provide AC coupling so no DC flows through the water. I notice you've attached a datasheet for the TTL/LS 7414. This circuit will only work with CMOS gates because they have a high input impedance. It won't work with older TTL gates because their input impedance is too low...
  15. Hero999

    Water Level Indicator

    The cork idea is a good one. Doing it electronically is more complicated. Here's an idea which should work in an automotive situation where the water is already connected to the vehicle chassis.
  16. Hero999

    Please help

    He mentioned antennae which implies he wants electromagnetic radiation. If he wants sound that would work but only to 10Hz with a decent subwoofer, not 0Hz.
  17. Hero999

    Water Level Indicator

    All good ideas John but be warned about the ones which pass DC through the water which can cause corrosion problems due to electrolytic action.
  18. Hero999

    Please help

    It won't work because to radiate a significant amount of power the antenna needs to be a significant length compared to the wavelength you want to transmit with 1/4 of a wavelength being optimal. The wavelength of an electromagnetic wave can be calculated using the following formula: l = c/f l...
  19. Hero999

    Please help

    You haven't provided enough information. Why do you want to do this? You need to be aware that you can't directly transmit 0Hz through the air and transmitting frequencies below 100kHz or so is difficult. You can however transmit a much higher frequency i.e. 27MHz and superimpose the lower...
  20. Hero999

    Hello to all ................

    I'm glad you like it and hope you stary around and contribute to the community.
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