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  1. KrisBlueNZ

    Need help with Camera multiplexer

    Hi and welcome to Electronics Point :-) You need to provide open collector (or open drain) outputs that close to the 0V rail to activate the functions. This is done with NPN transistors or small-signal N-channel MOSFETs. I'll assume you will use transistors. You'll need one for each output...
  2. KrisBlueNZ

    Faulty power connectors

    I've had problems with power cables supplied with cheap Chinese laptop adapters. All that copper in those cables is expensive, you know, and they want to save every cent they can. So they supply cables that don't have enough strands and/or with strands that are too thin. And they also seem to...
  3. KrisBlueNZ

    Help Getting Started with PIC Microcontrollers

    Are you using AVG Free? If so, that's a known issue. See http://forum.pellesc.de/index.php?topic=5981.0 and http://forum.pellesc.de/index.php?topic=4709.0 (I found these by Googling virus in pelles c.)
  4. KrisBlueNZ

    int64 variable, ms5611 sensor

    OK, I'm working from the data sheet at http://www.meas-spec.com/WorkArea/linkit.aspx?LinkIdentifier=id&ItemID=8497. The first calculation that requires a value wider than 32 bits is the TEMP calculation, that calculates the current temperature. The result is in units of 0.01 °C (e.g. 2007 means...
  5. KrisBlueNZ

    Help Getting Started with PIC Microcontrollers

    For PIC programming, use MPLAB. The new version is MPLAB X. Downloadable from http://www.microchip.com. For general purpose C programming for Windows I recommend a package called Pelles C. It includes an IDE and can generate executables for various types of Windows environments.
  6. KrisBlueNZ

    int64 variable, ms5611 sensor

    You should be able to use int32 variables instead of int64 variables, with some loss of accuracy, by simply scaling down the constants by dividing them by 232, which is 4294967296.
  7. KrisBlueNZ

    Measuring Sine Wave Using ADC

    The MAX1204 uses a three-wire SPI (serial peripheral interface) connection to a host microcontroller or microprocessor. Have a look at Figure 6 on page 13 of the data sheet. This diagram shows the signals you need to provide to the MAX1204 in order to read the data back from it, one bit at a...
  8. KrisBlueNZ

    Please, help me with this intercom setup.

    So the system still works fine if you only have two stations? And when you connect the other two stations, the voltages on the wires for the first two stations are affected? If that's really the problem, and you're sure you have connected all the stations together correctly, try this. Connect...
  9. KrisBlueNZ

    [woo] Does anyone know of this breakthrough technology ?

    As if there was any doubt... http://www.reuters.com/article/2012/01/23/idUS88382+23-Jan-2012+BW20120123
  10. KrisBlueNZ

    [woo] Does anyone know of this breakthrough technology ?

    There's not enough information there to show that the testing was done correctly. No faculty members are named. For all I can tell, this could just be the result of UltraEnergy Australia approaching a couple of students and paying them to produce an official-looking report containing the...
  11. KrisBlueNZ

    Repairs to fog machine

    Do you know whether the other fog machines drive their pumps with a phase-angle-controlled supply? They could drive it with a full cycle supply with variable voltage. This would be a lot harder to generate. Is the fog machine you're working on a cheaper product than the others? Maybe they made a...
  12. KrisBlueNZ

    [woo] Does anyone know of this breakthrough technology ?

    Perhaps they took the picture from one web site, and the description from a different web site.
  13. KrisBlueNZ

    Designing a Time Delayed Relay

    That was only for a Darlington. OK, go for it :-)
  14. KrisBlueNZ

    [woo] Does anyone know of this breakthrough technology ?

    Oh yeah. They know what they're talking about. Uh huh :-)
  15. KrisBlueNZ

    Homemade automatic plant waterer

    Here's what I suggest. It's a two-transistor Schmitt trigger (Q1,2) driving an N-channel MOSFET (Q3) that drives the watering pump (M1) directly. It requires a 12V supply. VR1 and the soil between the probes form a voltage divider that determines the voltage at the bottom end of R1. Damper...
  16. KrisBlueNZ

    Need 12v in a portable system, how should i approach this?

    I guess I would use a battery of Li-ion or Li-pol cells to provide 12V and step it down to 5V with a buck regulator. Check the input voltage range of your screen though; if it's narrow, you might need to use more cells and another buck regulator to step the higher voltage down to 12V.
  17. KrisBlueNZ

    7 segment display and CMOS

    I think we're hoping you will take some of the initiative and look for existing examples of the things you want to do. As I see it, these things are: Connect a rotary encoder to an Arduino so your code can detect when it is rotated, and the direction of rotation; Maintain a counter that is...
  18. KrisBlueNZ

    popping actuator

    Try Google. You have the magic keyword, "solenoid". Also, try electronic component e-tailers and robotics component e-tailers.
  19. KrisBlueNZ

    Repairs to fog machine

    I don't know much about pumps, so I can't tell you specifically what problem might cause a pump to run fine at full-cycle 110V AC but run very poorly at 50% phase-angle-controlled supply, but I think it's quite possible that it could. That pump is probably not designed to run from a...
  20. KrisBlueNZ

    Please, help me with this intercom setup.

    That's quite a nice little design! OK, start with a specific case and figure out why it's not working. For example, say station #1 transmitting to station #2. Disconnect stations #3 and #4, if possible, so they don't confuse the issue, and check that there's still a problem. Measure the...
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