Regulated Servo Power Supply

[ekindler0584]

Hello All...
This is a follow-up to my "Multiple Linear Regulators" question in the general area, (for anyone that looked at it).

What I am trying to do is use a single 7.2v NiMH supply for a small to medium sized tracked robot. It will be driven by two (large) servos. I want to regulate the power supply to the servos down to 5v, to maximize servo life, and minimize rotational speed. These servos use a no load running current of 700mA and stall around 7 to 8A. What I *want* to use to do this is a couple 5v, 7.5A low-dropout regulators i have laying around. The problem is that I am using a BotBoard and the servos will be run off the same supply. Someone suggested using two regulator circuits with the outputs ran through two diodes before "joining" them together (although this is not a prefered setup as they pointed out).

Anyone have any other suggestions? My thought is that the diodes are going to drop the supply voltage below what I am looking for. So maybe a seperate circuit for each servo would be better????Also, has anyone successfully ran Hitec servos of a 7.2v supply for a long duration?


Thanks,
Ed

[rshayes]

The simplest solution, if there isn't any reason to the contrary, might be as you suggested, use a separate regulator for each servo. The current rating on the regulator seems to be quite compatible with the current requirement for one servo.

A switching requlator might be slightly more efficient, but would be considerably more complicated.