Servo with higher voltage

[jozef007]

Hi,
I have servo A26DLR. It can run on 4.8V and 6V. I have such dillema:
1. What is higher safest voltage which I can feed it (for motor)
2. What is highest safest voltage for signal control

here is pdf wiht details
[mod edit: removed dysfunctional link]

Appreciate help.

Thx

 

[WHONOES]

The link doesn't seem to work. I assume your device is a radio control servo. If the blurb that comes with it says the it will work between 4.8 and 6V then that is the range it will work over. The receiver driving it will supply the right signal for correct functionality regardless of supply voltage. BTW running it at 6V will give you more torque.

 

[jozef007]

 

[bertus]

Hello,

Here is the complete datasheet from the link.

Bertus

 

[jozef007]

Reason being is that at full batteries I will have 7.6V, lowest probably 5.4 V, at highest voltage I can will use DC-DC voltage regulator,
but around 6.5V probably will switch it off, since I can use such voltage. It making some complication to the schematic, therefore I'm investigating If I can run 6V servo on 7.6V. Also question is what can be highest voltage for control pin?

 

[WHONOES]

If the datasheet says 6V max, then that is what it will be. You will probably damage them running on 7.6V.
A simple 5V regulator will do it. Switching or analogue. The analogue type might require a small heatsink.

 

[Bluejets]

There are servos available which will run up to 8.4v

 

[jozef007]

Unfortunately for my purposes (size, price, performance) is the best choice. Question is if my batteries have voltage from 7.6 to 5V what is the best way to do it. I can use Low Drop voltage regulator, but I will lose part of usable power (from 5.5 to 5V is voltage drop will be around 0.5V). Maybe to regulate to 6V (with input 6.5) and after switch to bypass regulator. So far is the best what I have in mind. Unless guy you have some idea about that..

 

[WHONOES]

The easiest would be to use a 4 cell NiMh battery which gives 4.8V.
You could regulate your battery to 5V. A small volt drop as the battery is used up will not cause the servo to not function. The afore mentioned NiMh battery will drop to 4V when exhausted but the servos will carry on working till the battery gives up, they will just get a little slower and have not quite as much torque.
I've always used the 4.8V packs without any problems.

 

[Martaine2005]

Or.... put a couple of diodes in series?

 

[WHONOES]

Or.... put a couple of diodes in series?

Yeah, he could do that. Wouldn't be my choice though.

 

[Martaine2005]

Wouldn't be my choice though.

Mine either really.
It was more to do with the OP's concern about regulator drop out and then a bypass switch.
Simpler to series a couple of diodes.
I am with you though, a 4.8v pack. All my models have 4.8v receiver packs and some work for an hour or more. Some of my larger helicopters have 9 servos. They easily run for half hour. I don't take chances with them. While home and checking settings and pitch etc, the packs will last several hours.

Martin

 

[Harald Kapp]

Use a buck-boost converter, e.g. like this one. It will step down high input voltage and step up low input voltage.

 

[WHONOES]

Mine either really.
It was more to do with the OP's concern about regulator drop out and then a bypass switch.
Simpler to series a couple of diodes.
I am with you though, a 4.8v pack. All my models have 4.8v receiver packs and some work for an hour or more. Some of my larger helicopters have 9 servos. They easily run for half hour. I don't take chances with them. While home and checking settings and pitch etc, the packs will last several hours.

Martin

I just do fixed wing with anything from 2 to 6 servo's. Have tried some electric where the speed controller has a 5V output for the servo's. Not to keen on those though. I prefer something that goes bang frequently.

 

[jozef007]

at the end, I will go with solution to keep voltage around 6V(battery is going from 7.6V and use voltage regulator), when voltage will drop bellow 6V I will bypass regulator and feed system directly from batteries. This should work and be efficient. Thank for all you help and time. Please consider issue as resolved.