need servo help

[galannthegreat]

I got a Hitec HS-311 servo and i'm looking to power it via my bot power, which is 7.2VDC, but apparently it's not good to put that much overvoltage through a servo. So, I have an idea if I use a diode with a sufficient voltage drop that will work. I'm just looking for the right one, I need one that can drop the voltage by atleast 1.2-1.6VDC, any part suggestions?

[Razor Concepts]

You are using a voltage regulator for the microcontroller, right? If you are then you don't need to do anything, the servos will already be at 5 volts.

[galannthegreat]

Don't you think that'll put the VR under to much stress with all of the drain from the motor and all? So all I need is to have a sufficient diode for a sufficient voltage drop... but which diode would be good to use?

[frodo]

just use the VR. it should be alright  if you need a diode get a normal diode with voltage drop of how much you need to drop to get to 5V

[galannthegreat]

I need a drop of about 1.5 volts. Any diodes that you think would work? I've tested all of mine and they don't do the job alone, but if I connect the same type in series I could achieve that. Would it be a problem if I pretty much daisy chained a few?

[frodo]

no it wouldn't be problem to string together diodes

[galannthegreat]

thanks, I think I'll use three 1N4001 diodes then.

PS If you know of any other diodes with a larger Voltage Drop than .53V, plz let me know.

[Admin]

Expect 0.5 amps to go through your HS-311. That means if you use a voltage regulator or diodes, it needs to be able to handle at least that much current.

[galannthegreat]

Ah, so basically if I'm using diodes it may be "suffocating" the servo of current it needs, correct me if I'm wrong.

[Webbot]

Ah, so basically if I'm using diodes it may be "suffocating" the servo of current it needs, correct me if I'm wrong.

What Admin means, I believe is that since the diodes are in series with the servo then whatever current goes tru the servo will also go through the diodes. Admin says 0.5A and since the 1n4001 can cope with 1A then you are ok. But you may want to check the servo by making it staill (by holding the wheel so it doesn't move) and check that the current desn't go above 1A.

IF the supply for the servos is coming via a regulator then add up the requirement for each servo and make sure the regulator can supply the total. ie if you have 3 servos requiring0.5 amps each then total = 1.5 amps. So if the regulator can only supply 1Amp then it will burn out.

[galannthegreat]

Ah, thanks that helps a lot.