Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: goatfish on March 07, 2008, 09:35:22 PM

Title: $50 robot schematic batteries
Post by: goatfish on March 07, 2008, 09:35:22 PM: on the schamatic for the $50 robot which batterie are you meant to use?the 9 volt or the battery holder in my case? :)
Title: Re: $50 robot schematic batteries
Post by: pomprocker on March 08, 2008, 12:21:43 AM: the 9volt powers the electronics (atmega8, and sensor bus) which goes through the voltage regulator to step it down to 5volts, the 4 battery double A battery pack will hold 4 1.2volt NiMH batteries that provide 4.8 volts to the Servo Bus.
Title: Re: $50 robot schematic batteries
Post by: Trumpkin on March 08, 2008, 01:19:11 PM: Even tho it's cheaper to do it the 9 volt battery way. I suggest you use an NIMH rechargable battery pack.
Title: $50 robot schematic batteries
Post by: Pierre on October 04, 2009, 08:47:50 AM: I wonder if it will fry the servos if I use a 7.2V battery pack instead of the 4.8V battery pack?

The actual HS-311 servos operating speed is 4.8V from the original box but does not mention about a maximum voltage.
Title: Re: $50 robot schematic batteries
Post by: Pierre on October 04, 2009, 09:11:14 AM: I have my answer and unfortunately the operating voltage is 4.8 to 6 volts.

Detailed Specifications

Control System: +Pulse Width Control 1500usec Neutral
Required Pulse: 3-5 Volt Peak to Peak Square Wave
Operating Voltage: 4.8-6.0 Volts
Operating Temperature Range: -20 to +60 Degree C
Operating Speed (4.8V): 0.19sec/60° at no load
Operating Speed (6.0V): 0.15sec/60° at no load
Stall Torque (4.8V): 42 oz/in (3.0 kg/cm)
Stall Torque (6.0V): 49 oz/in (4.5 kg/cm)
Current Drain (4.8V): 7.4mA/idle, 160mA no load operating
Current Drain (6.0V): 7.7mA/idle, 180mA no load operating
Dead Band Width: 5usec
Operating Angle: 45° one side pulse traveling 450usec
Direction: Multi-directional
Motor Type: Cored Metal Brush
Potentiometer Drive: 4 Slider/Direct Drive
Bearing Type: Top Resin Bushing
Gear Type: Nylon
360 Modifiable: Yes
Connector Wire Length: 11.81" (300mm)
Weight: 1.52oz (43g)

I guess I will rather buy a battery pack at 6 volts then possibly fry the servos at 7.2V.
Title: Re: $50 robot schematic batteries
Post by: walkercreations on October 04, 2009, 02:52:55 PM: Only thing I would add is that I am a Radio Control Helicopter pilot and most servos will only take 6V or less. If you use anything over 6V you really should use some type of voltage regulator to keep from possibly burning out your servos.
Title: Re: $50 robot schematic batteries
Post by: Dont_Taz_Me_Bro on October 04, 2009, 11:37:52 PM: Quote from: Pierre on October 04, 2009, 09:11:14 AM
I have my answer and unfortunately the operating voltage is 4.8 to 6 volts.

I guess I will rather buy a battery pack at 6 volts then possibly fry the servos at 7.2V.

Well the battery pack recommended in the tutorial is 6 volts I believe, but after reading the tutorial on batteries it appears that initially the voltage could be as high as 7 volts for a fully charged 6 volt battery so if that is indeed the case....perhaps you would be fine with your 7.2 v battery.

Here is the tutorial I'm talking about and where it states that a fully charged battery could have a 15% higher voltage rating.

http://www.societyofrobots.com/batteries.shtml (http://www.societyofrobots.com/batteries.shtml)
Title: Re: $50 robot schematic batteries
Post by: Pierre on October 05, 2009, 03:08:56 PM: Thank you both walkercreations and Dont_Taz_Me_Bro ;)