Search results

  1. audioguru2

    Passive audio filters

    Hi Vainajala, Your old speakers' response is pretty bad, hopefully only due to room reflections. That is quite a big hole at 1.8KHz. I've seen very good speakers measure even worse in a room. I take my speaker to the backyard, point it straight up, and hang the microphone above it on a fishing...
  2. audioguru2

    ultrasonic mosquitoes repeller

    Yeah man, that's cool.
  3. audioguru2

    detector prototype

    Hi Badai, Your untuned detector will probably pickup local TV and radio stations and any other nearby transmitters such as taxicabs. It may not be sensitive to a hand-phone that is transmitting at an extremely high frequency of 1.8GHz, unless proper UHF and microwave wiring techniques...
  4. audioguru2

    ultrasonic mosquitoes repeller

    Hey Darrin, Instead of buying that expensive gadget that makes heartbeat sounds that they say are, "inaudible to humans", why not just loop the beginning of Pink Floyde's, The Dark Side of The Moon rock song? Feed the 16Hz heartbeat into a high-power amp and a big subwoofer. Then if you don't...
  5. audioguru2

    Lowpass for subwoofer -project

    Hi Vainajala, To get more subwoofer power, does the Peerless driver come as a 4 ohms model? He, He. If not, are you going to wind your own voice-coil? Or build another one and parallel them? The small difference of about 2dB between 60W and 100W probably isn't worth it. The sub will gain 6dB in...
  6. audioguru2

    simple question

    Hi Shekhar, If it's a high-current ammeter, and the power supply isn't protected with current-limiting or a fuse (which certainly is not ideal), then the ammeter will smile while watching the power supply burn. Don't try it with a car battery, which is a fairly ideal power supply!
  7. audioguru2

    ultrasonic mosquitoes repeller

    Hi Ben, Welcome to our forum. The ultrasonic sound from the piezo tweeter might actually attract mosquitoes, if they can hear that high, because they might think it is a nice warm bat that is making the sound. But they probably know what bats do with mosquitoes (their dinner), so will be...
  8. audioguru2

    Latch triggering

    You are connecting a battery to a power supply? Read the warning label on the battery.
  9. audioguru2

    RJ45 network card to IR

    Why aren't modern parts available in Aus? Just dig a channel in the dirt floor of your cave and bury that dangerous cable! (Get kangaroos to do the digging)
  10. audioguru2

    Headphone Plug

    Hi Quantum, You want a pic, OK, here's a pic. Although headphones don't have Positive and Negative, because they operate on AC, I have shown Pos and Neg to indicate phase connection. The standard is that if Pos is applied to the Pos terminal and Neg to the Neg terminal, the cone will move...
  11. audioguru2

    Audio Signal Switch

    Hi GPG, Good find! That new MAX4617 is even better than the improved MAX4066 or MAX4051. You're right, its charge-injection is minimum with a bias of 0.6V. The resulting 1.2Vp-p is plenty of headroom for low impedance microphones.
  12. audioguru2

    Headphone Plug

    Hi Quantum, Headphone and their plugs don't have positive and negative, but instead have left channel, right channel, and a 3rd terminal where the common wire of each channel is connected togerther which is usually grounded. On the outside of the plug, the "tip" is one channel, the "ring" is the...
  13. audioguru2

    Latch triggering

    If both oscillators are being powered by the same small battery (9V?), then they might crudely syncronize if the battery voltage jumps up and down due to the oscillators' currents through the internal resistance of the battery. Especially with 555 oscillators, which cause supply-current spikes...
  14. audioguru2

    7805 overheat and Clock signal

    Hi Chrono, Sorry that I confused CPU with controller. The transistor will work much better with a collector resistor. The 7805 shuts-down when its internal temperature reaches 125 degrees C, to protect itself. So it will cycle on, off, on, off, etc. Your whole circuit will go beserk! I can't say...
  15. audioguru2

    Convert 0-30V 3A PSU to 5A or more

    Hi Sam, Welcome to our forum. Sorry for the long discussions and confusion. In the other post, I made a parts list with up-to-date revisions. I don't know if someone has a revised PCB layout. Either it works well but nobody says anything, or nobody tried it yet. This thread recently posted a...
  16. audioguru2

    IR Remote Control Tester

    Hi Steven, Your sparks go everywhere. Xenobius, I finally found the project, here: http://www.electronics-lab.com/projects/test/003/index.html The photo-diode probably works as a voltage generator, not a photo-conductor as in the article.
  17. audioguru2

    7805 overheat and Clock signal

    Hi Chrono, As the article says, the controller is clocking out its data "at about 60Hz", which might be the same (they don't say) as your mains clock. If the clocks aren't exactly the same (frequency and phase), then your decoder will be intermittent. So what's wrong with your 7805 heater and...
  18. audioguru2

    nice title

    Hotwaterwizard, Chic Seaker? You don't need this electronic finder circuit to find chics, do you? Ha!
  19. audioguru2

    7805 overheat and Clock signal

    Chrono, If your transformer is 13.5VAC, then the rectified and filtered voltage at the input of the 7805 is about 17.5V. That's nearly 3 times higher than is necessary, and since power (heating) equals Voltage times Current, then the amount of heating is also nearly 3 times more than is...
  20. audioguru2

    Lowpass for subwoofer -project

    Hi Vainajala, Your Peerless 8" woofer certainly isn't very small. It has a very long throw for its size and has a big magnet. Although its spec's don't mention power, its 1.5" coil should be able to handle plenty. Your transfer function curve shows a dropping response due to its very low Q...
View older results
Top