by subpilot » Tue Aug 01, 2006 3:06 am
by subpilot
Tue Aug 01, 2006 3:06 am
I have been running a International Rectifier iP1203 Buck converter. It works great but the evaluation module is pretty expensive.
I see that Texas Instruments have released the TPS54550 converter and they sell the evaluation module for very little money.
http://focus.ti.com/lit/ug/slvu151/slvu151.pdf
I had tried a TPS54350 but found that despite its rating it did not like the load the servos presented. That may be because of the motor inductances causing the tank circuit to not operate correctly. The datasheet for the eval board says 3.3V output but you can adjust it to 6VDC with a resistor change.
The 550 may have the same issues as the 350. Maybe tweaking the output filtering could solve the problem?
What I think is the best solution is to be able to run the servos off the 2 cell LiPo packs without a regulator. The limiting factor appears to be the motors in the servos. I very much suspect there is a motor defect problem and many are failing at 6V let alone at the up to 8V you get from the LiPos.
I have been running a International Rectifier iP1203 Buck converter. It works great but the evaluation module is pretty expensive.
I see that Texas Instruments have released the TPS54550 converter and they sell the evaluation module for very little money.
http://focus.ti.com/lit/ug/slvu151/slvu151.pdf
I had tried a TPS54350 but found that despite its rating it did not like the load the servos presented. That may be because of the motor inductances causing the tank circuit to not operate correctly. The datasheet for the eval board says 3.3V output but you can adjust it to 6VDC with a resistor change.
The 550 may have the same issues as the 350. Maybe tweaking the output filtering could solve the problem?
What I think is the best solution is to be able to run the servos off the 2 cell LiPo packs without a regulator. The limiting factor appears to be the motors in the servos. I very much suspect there is a motor defect problem and many are failing at 6V let alone at the up to 8V you get from the LiPos.