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  1. BobK

    Convert 6v to 12v

    No, but you should stop quoting it! Bob
  2. BobK

    Help me build a battery charger?

    No, you need one with a 7V output. Bob
  3. BobK

    Digital circuits

    What does the dongle do? Bob
  4. BobK

    Digital circuits

    Interesting, I am going to have to look that up! Bob
  5. BobK

    Soundboard help!

    How about something like this: I suspect that this is a bit better than a greeting card one and it looks like it is small enough to fit in your space. http://www.ebay.com/itm/50-second-USB-sound-voice-recording-module-/250406358339?pt=LH_DefaultDomain_0&hash=item3a4d61cd43 Bob
  6. BobK

    Heavy duty fixed frequency radiant charger project

    Shouldn't this thread be combined with the "Cold Smoke Blower" thread? Bob
  7. BobK

    Digital circuits

    Modern radios use frequency synthesis instead of a variable capacitor to tune. If you are planning to build a retro radio with a variable air capacitor, I supose you could use a servo to turn it. Bob
  8. BobK

    Scratchbuilding an AM receiver--maybe a replica TR-1?

    Electronic components come as go over time. It is highly doubtful that you will be able to find any of these: 1. the transistors (these are probably germanium) 2. the tuning capacitors 3. the IF transformers Radios today are built completely differently, so there is no longer a need...
  9. BobK

    Scratchbuilding an AM receiver--maybe a replica TR-1?

    Sourcing the components for that might be a bit difficult... Bob
  10. BobK

    how to store something

    Well, a Leyden jar could store 1 bit. http://en.wikipedia.org/wiki/Leyden_jar Bob
  11. BobK

    Soundboard help!

    How long a sound do you expect to play? A microcontroller with PWM or DAC output and enough code space to store in the sound in the flash memory would be a possibility. You would also need an audio amp. For longer sounds you could also use external ROM. Bob
  12. BobK

    Soundboard help!

    http://www.amazon.com/s/?ie=UTF8&keywords=recording+module&tag=googhydr-20&index=aps&hvadid=10258553901&hvpos=1t1&hvexid=425421&hvnetw=g&hvrand=1903188611307897479&hvpone=&hvptwo=&hvqmt=b&ref=pd_sl_2n06nadxr8_b Bob
  13. BobK

    Reconfigurable Computer

    Your best bet would be a development board from Xilinx or Altera. They can be had for < $100. Bob
  14. BobK

    Reconfigurable Computer

    What do you mean by a reconfigurable computer? The essense of a computer is that it is reconfigurable via programming. Are you talking about something different than this? Do you expect to re-program the FPGA on the fly? Why? What is it you are really trying to do? Bob
  15. BobK

    Looking For A Low RPM <30rpm Motor

    A gear motor is a motor + a gear box, so no, you do not need a gearbox if you find a gear motor going at the desire RPM. Motors are not rated in Kg (unless it is the weight of the motor). The are, as I said before rated in Kg cm. You need to learn some basic physics. Keeping a weight...
  16. BobK

    Battery Pack woes.

    I doubt that using a boost converter would get you much more. It will not be 100% efficient, so you will be losing power by using it throughout the cycle, and it will end up drawing more current as the voltage gets lower. Maybe your best bet is to find a TV that uses less power. Bob
  17. BobK

    Battery Pack woes.

    Well, there are several problems. 1. The capacity of cheap Chinese batteries on Ebay is often overstated. 2. Battery capacity is stated at a particular current draw, typically the one that maximizes the capacity. So any other draw will get less that the stated capacity. 3. Paralleling...
  18. BobK

    Looking For A Low RPM <30rpm Motor

    You have to understand torque. Torque is the product of a radius and a force. Say the motor is going to spin a disk that is 10cm in radius, and it takes a force of 3kg to push the outer edge of that disk to rotate it. Then a torque of 30 kg cm is needed. If you can figure out your...
  19. BobK

    JDM pic programmer help required

    How much is your time worth? A PICKit 2 programmer from Microchip costs all of $35 and you will save many hours by buying one. Bob
  20. BobK

    IR sensor

    If you can't be more specific, we can't help. Bob
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