Dolphin Rev 09 board has different type resistors than the troublesome old ones.

by Steve Hobrecht
(Northern California)

Rev 09 PC Board

The photo above shows a Rev 09 Dolphin by Maytronics PC board. Interesting, the unit I purchased, with a 6 month later build date, uses the Rev 03 board. The PC board has been laid out slightly different but looks to be the same circuit design as the earlier revision. Note that on this board, the component numbers are deleted but they share the same values. The sticker on the same Atmel processor has the same "Diag DC" label but differing run numbers. One interesting note is that the M3 DMOS has been changed from a 60V to an 80V breakdown device implying there have been some problems with a failure of that device (my device was shorted resulting in the burning out of the 18 Ohm, R31 as others have reported). The current sensing resistors, R31 and R14 values are the same but the newer board uses surface mount resistors. R43 remains the same value but appears to be larger, being able to dissipate more power safely. All of these changes appear to improve weaknesses of the original design. These changes have been suggested by myself in previous postings concerning Rev 03 based upon generally accepted design practices when specifying components.