Feature Review

Since the first version of the software is now complete I was thinking this might be a good occasion to summarize the features and functions of the Bi-Onda TT motor controller as they are now implemented.  I must admit I had an idea for a new feature last night but I will keep this on the back burner for now.  Gotta stop somewhere.

So let's take a look at the feature list.

Characteristics

• Dual DDS sine wave generation.
• Adjustable frequencies with a resolution up to 0.01 Hz.
• Micro controller DDS generation, 16MHz quartz clock, interrupt driven
• Chebyshev low pass filters
• Power Op-amp amplification up to +-15V with transformer boost to 120+VAC
• Adjustable output levels
• LCD 16x2 character backlit display
• 33.3 & 45 RPM speed generation
• EEPROM storage of calibration settings
• Remote expansion header to allow incorporation of all, or some, operating buttons into the turntable, parallel to the buttons on the Bi-Onda.

Operating Modes

User selectable operating modes:

• Continuous always-on mode with single or dual sine wave out as mains source
• Switchable on-off mode with dual sine wave, phase shifted for direct drive of motor coils

Features

Run Mode

• Calibrated sine output for 33.3 and 45 RPM operation
• Speed selection
• Speed adjust with selectable resolution: 1.0Hz, 0.1Hz, 0.01Hz (during play and in CAL mode)
• Incr Decr speed buttons
• Motor acceleration startup (spin-up)

Calibration Modes

• 33.3 RPM Calibration
• 45 RPM Calibration
• Phase Shift adjustment (1.4 degree steps)
• Operating Mode selection
• Acceleration Mode (on or off)
• Acceleration Parameter Adjust (start frequency, frequency step, step delay)

This should pretty much cover most needs as a power source upgrade or for custom turntables.  The one thing left to do is determine the total power handling capacity based on the components (op-amps, transformers, etc.) currently in use and possible alternatives to drive motors with lower voltage requirements or motors with higher wattage ratings.