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  1. KrisBlueNZ

    How to communicate between two devices?

    Just a thought... Any battery that can drive lighting-grade LEDs for a significant time will add some mass to your helmet, which might limit your ability to turn your head quickly. If that was a problem, you might need to move the battery off the helmet, and connect to the helmet with a very...
  2. KrisBlueNZ

    Driving two motors using a single current driver

    Hello and welcome to Electronics Point :-) The diagram you've drawn should work fine. I don't think you'll need diodes across the motors to suppress the back EMF because each motor/diode pair will suppress the back EMF of the other motor. It might be more "professional" to use two separate...
  3. KrisBlueNZ

    IR volume control for Onkyo AV receiver?

    It might be worthwhile buying a universal remote (you can get them very cheaply at two dollar shops here in New Zealand) and trying the volume buttons on each of the settings, starting with the Onkyo ones (if it has them). They may have used a custom protocol or custom variant for this model, or...
  4. KrisBlueNZ

    Securing component to heatsink

    If you need to insulate the package's metal tab (which is normally connected to the centre pin) from the heatsink, then use the insulating washer with a small amount of thermal paste on each side of it. If you don't need insulation, use a very small amount of thermal paste between the package...
  5. KrisBlueNZ

    int64 variable, ms5611 sensor

    dT is only adjusted temporarily, during the calculation of TEMP. That code does not change dT at all. The calculation I chose, TEMP, is a simple one, because the result was already specified as a 32-bit variable. I didn't change the definition of the result variable; I only changed the values...
  6. KrisBlueNZ

    Designing a Time Delayed Relay

    Yes, sure. It doesn't need to be 1A 400V. These ones are 0.5A 100V which is plenty, and I think they're smaller: http://www.digikey.com/product-detail/en/MB4S-TP/MB4S-TPMSCT-ND/722465 http://www.digikey.com/product-detail/en/MB1S/MB1SCT-ND/2094421 8k2. Save the image and view it with an image...
  7. KrisBlueNZ

    design 1A current limiter for my 300V dc supply

    Also, the voltage regulation will be pretty poor - the voltage adjustment potentiometer is supplied from the unregulated voltage rail! Edit: The MOSFET is connected as a source follower (common drain) so it will work, but the power dissipation is definitely an issue!
  8. KrisBlueNZ

    Difference between 2A104J Capacitor and plain 104 Ceramic ones on LM2917

    Type II ceramic capacitors aren't very suitable where stable capacitance is required. Their capacitance varies significantly with applied voltage, and of course with temperature. Z-type dielectrics are the worst. Also they are common targets for cheap low-quality manufacturers, because they're...
  9. KrisBlueNZ

    Designing a Time Delayed Relay

    Because compromises! Each pin of a pluggable Combicon is rated for 16A, I think, so strictly speaking a 2-pin or 4-pin connector would be adequate. But experience tells me to use more pins than are needed, i.e. to engineer conservatively. But if another factor makes the whole project unworkable...
  10. KrisBlueNZ

    Designing a Time Delayed Relay

    I really recommend pluggable Combicon, unless you're really trying to minimise cost. They are much more convenient, safer, and they don't take up any more board area than the wire-to-board type.
  11. KrisBlueNZ

    Designing a Time Delayed Relay

    Sure, sounds fine apart from "screw termination blocks" - are these pluggable? Or do you screw the wires into the board-mounted connector? Pluggable is a lot better, although more expensive.
  12. KrisBlueNZ

    Designing a Time Delayed Relay

    BTW what connectors are you using? If you're using the Phoenix type that I suggested, you can save space by using 6-pin connectors for the current circuits. Or even 4-pin.
  13. KrisBlueNZ

    Assembly statements

    Right, the difference is as shumifan50 described. Also the fact that macros accept parameters makes them more flexible than function calls; functions can accept parameters, but they need to be accessed and tested by code within the function, which branches according to the parameters. With...
  14. KrisBlueNZ

    Constant current power supply

    Yes you can use 2N3054 and 2N3773. They are both a bit low on gain but that's OK. Yes any TL431 will work; the CLP suffix I specified means commercial temperature range and TO-92 suffix, so I think that's what you'll end up with anyway. No you don't need to use stripboard. Is that layout...
  15. KrisBlueNZ

    Assembly statements

    You just place a label at the end of the loop, and have two or more conditional statements that jump to that label. loop: blah blah blah subwf filevar,w bz breakloop ; (bz is a macro) bnc breakloop ; (bnc is a macro too) btfsc portx,bitn ; skip next...
  16. KrisBlueNZ

    Resistor types and power ratings

    Hi Terry and welcome to Electronics Point :-) The Vishay web site (http://www.vishay.com) has the following information about the CPSL series resistors: They are low-inductance wirewound resistors. Standard wirewound resistors have significant inductance because they are wound like an...
  17. KrisBlueNZ

    Help Getting Started with PIC Microcontrollers

    Other antivirus programs were also mentioned in those threads I linked to. Detecting viruses isn't an exact science; false positives do happen, and every antivirus suite has slightly different performance. I think the chance of Pelles C having a genuine virus is pretty low. It's an original...
  18. KrisBlueNZ

    Please, help me with this intercom setup.

    C'mon Steve. What have you got against diodes? No, they bias the adjacent diode into conduction, putting a positive voltage on the corresponding channel audio signal while coupling the audio from the output of the microphone amplifier onto the channel audio signal as well. Have a look at the...
  19. KrisBlueNZ

    Measuring Sine Wave Using ADC

    Your problem description isn't very clear but I think I've figured out what you're asking. You can feed 1.2V DC into the MAX1204 and read that back as a converted value of 0x12C or 300 decimal, which is correct for a 10-bit ADC with a 4.096V reference, right? So you want to acquire a 1.2V peak...
  20. KrisBlueNZ

    Please, help me with this intercom setup.

    Sorry, I put the diodes in the wrong place! Try this.
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