To regulate or not to regulate? that is the question

[Adi Kochav]

Hi All


When using a regulator you'll always get the same current to the servos, this will give you the same power and speed throughout the entire flights, from flight 1 to flight 6.

Also, the servo is working in its optimal 7.4 v for example, so anything above it or anything below it will make it work good but not efficient and effective it suppose to be.

With the new HV servos breed we have on the market, I see more pilots that are not using regs at all, and if they do its only when they use power bus / expenders and such.

What is the reason for that?
Why no using a regulator?

[Brad Davy]

With digital servos, the speed and position will be consistent as long as the supplied voltage is in the servo’s rated range. Unlike the analog servos that changed depending on voltage. An additional regulator just adds one more failure possibility, and adds additional weight. Regulators became popular when pilots wanted higher torque, but needed to regulate the voltage down to reach the rated range for servos. Digital technology used to center around 5 volts as the working voltage Because nicd and nimh batteries easily achieved this voltage. Lithium technologies however exceed that range. Hence regulators were needed.

Brad

[Dave Dupre]

If speed remains consistent for digital servos, why do specs always have different speeds based on voltage?

[Brad Davy]

If you look at the same data for analog servos, you’ll probably see a much larger difference in speed (as much as 5 times the difference (.05 seconds per 60 degrees) for a 1.5 volt change). Positioning is the real advantage of digital servos, and that won’t change based on voltage. I said consist over the rated voltage range, not exactly the same. And if you plot your discharge curve for your battery you’ll probably discover the difference between full charge and recharge voltages makes a .01 second per 60 degrees difference. This is probably well below the threshold for human differentiation.

I’m not saying don’t use regulators. I’m just responding to Adi’s question about why some people don’t use them.

Brad

[Dave Dupre]

Agreed. I doubt I would see the speed difference. The torque though looks like a big difference. Might mean some blow back if the voltage sags.

[Brad Davy]

That’s a servo sizing issue. Selecting your servos to provide sufficient torgue at the lowest voltage you’ll see eliminates that risk.

Also, by not using a regulator you’ll eliminate the wasted power associated with linear regulators.

Brad

[Adi Kochav]

Thank you very much friends for the inputs and the good info

[Charles Edwards]

Adi,

By regulating the voltage to the servos you will ensure that the servo performance will remain the same throughout you entire flying session. Without a regulator you servo speed and torque will become less during the course of the day. I typically us e a regulated voltage of 7.0v for both IMAC planes and Pattern.

[Charles Edwards]

Some interesting views Brad. The difference in speed and torque can most certainly be felt, this will mostly be relevant on Rudder and Ailerons in my opinion. In the past when upgrading servos I have felt the need to increase or decrease Exponential (depending on radio system) in order to maintain the same feel.