Anchor

From Hackstrich
Revision as of 18:53, 24 December 2010 by SarahEmm (talk | contribs) (I2C fix.)

Anchor will be an electronic current/voltage sink, for testing/characterizing power supplies and other similar tasks.

  • Desired features/specs:
    • Constant current and constant voltage options
      • Maybe constant power too?
    • Ramp-up/down automatically and track outputs
    • Pulse load to test transient response
    • 5A/100V maximums
      • 500W dissipation in a FET is a bit nuts, so it won't be 5A *at* 100V
      • 100W continuous, 500W pulse might be reasonable? Would be nice anyway.
    • Some kind of computer interface for more complicated tests/more detailed data analysis
      • USB would be easy to implement
      • Ethernet could be cool, but that seems overkill here
      • GPIB would be the traditional choice for test gear, but I've never done any work with it
  • PIC24FJ256DA210 will be used as it has all the graphics/LCD drive/acceleration built in to enable a nice colour TFT display
    • Inputs
      • Digital
        • Load On/Off
        • CC/CV mode?
        • 2 for UI quadrature encoder
      • MCU-integrated 10-bit ADC
        • Heatsink temperature
        • UI pot (if used)
      • I2C
        • LTC2453 I2C 16-bit ADC for current and voltage measurement
    • Outputs
      • Digital
        • 1 for a CC/CV mode relay (if required)
      • Analog/PWM
        • Output drive (to op-amp)
  • An LCD would be cool to plot the response of load variations without a PC (transient response, current limits, etc.)
    • Could use a simple STN monochrome panel, would be cheap and work well
    • Could alternatively use a touchscreen OLED, would be expensive but look really cool
    • Middle ground would be a touchscreen LCD, which would be not-crazy-expensive and still look pretty cool
    • With any of these options, want the critical UI bits to be physical controls (current/voltage mode/setting)