As long they can hanlde the voltage you are ok with the amps
I've done the same in a dual battery robot using a 6volt 4Amp Sealed Acid battery to feed the servos and the relays·as they·were·the most consuming device on it.
I believe most servo's were designed to work with 4 alkaline batteries (4 x 1.5 = 6), or 4 rechargeable Ni-Cd batteries (4 x 1.2 = 4.8). Or even 5 rechargeable Ni-Cd batteries (5 x 1.2 = 6). If you want to make sure, go to the servo manufacturer's web site and see the torque-voltage sheets. Parallax servo's are manufactured by Futaba, I believe.
In any event, yes, you should be able to use a 6-volt battery to drive them. I've heard you can 'overdrive' some servo's on 7 volts, but this DOES reduce the life of the motor inside the servo.
Ok...i'm quite sure that the voltage is suitable since the servo rates up to 7.5 V...but not sure about the current.it seems too high for me...i afraid it will fry my servos! or maybe i should brush up my understanding on power again...
Your servos will only draw whatever current they need, they have a certain resistance so they will draw I=E/R where E is the voltage and R is the resistance. As long as you supply the correct voltage and they aren't already damaged (like a short inside) they will work just fine.
Yes, the current is the 'dependent' quantity here. Ohm's law is: V = I*R, or Voltage = Current times Resistance.
What this means is, if you put a battery ( a voltage source) across a load (a resistance) then a certain current will flow. The 4.5 Amp-Hour rating on the battery is merely a statement of its capacity. It does NOT mean that it will run 4.5 amps through your servo as soon as you hook it up.
In fact, the higher the amp-hour rating of your battery, the more 'juice' it has, and the longer it will last between recharges.
Now, the voltage is critical. Too high a voltage will fry your servo (too high here being above 7.5 volts, apparently).
Comments
I've done the same in a dual battery robot using a 6volt 4Amp Sealed Acid battery to feed the servos and the relays·as they·were·the most consuming device on it.
Thanos
In any event, yes, you should be able to use a 6-volt battery to drive them. I've heard you can 'overdrive' some servo's on 7 volts, but this DOES reduce the life of the motor inside the servo.
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·1+1=10
What this means is, if you put a battery ( a voltage source) across a load (a resistance) then a certain current will flow. The 4.5 Amp-Hour rating on the battery is merely a statement of its capacity. It does NOT mean that it will run 4.5 amps through your servo as soon as you hook it up.
In fact, the higher the amp-hour rating of your battery, the more 'juice' it has, and the longer it will last between recharges.
Now, the voltage is critical. Too high a voltage will fry your servo (too high here being above 7.5 volts, apparently).