killbill
Resolved by Dunning-Kruger!
Hi,
I am planning on using a Micro Maestro 6-channel USB servo Controller with one Hitec 805BB 1/4 scale servo. I am in the process of hacking a 5vdc - 1.5 amp wall plug power supply to be used to power the servo. Using jump wires, I'm hoping to splice the power supply wire to the jumper wires and plug the female ends onto the posts on the Polulu controller.
Here's my question, all of the pre-made jumper wires with at least one female end that I have found online use 26AWG wire. Looking at a couple of online charts, this seems too thin a gauge to carry the power. (Note: The servo draws around 870mA during use.) I can't find 22AWG jumpers with at least one female end.
I'm not the greatest with this and don't want to melt the jumper wire housing. Can anyone out there tell me if 26AWG can actually handle between 870mA - 1A of power?
Any advice is truly appreciated. Thanks.
Most servos have that gauge wire to my knowledge. I would be more concerned about browning out the wall supply, as servos can draw upwards of 2A at stall and initial move.
Your ampacity of 26 awg will vary greatly depending on several things. type of metal the wire is made from, temperature, how long the run is. However the common thinking on 26 awg wire is 2.2 amps in open air and 1.3 in an enclosed case.
@Killbill Also as mentioned 1.5amp isn't nearly enough current to power an 805bb... Maybe if it had no load on it... I think it pulls 3amps + at stall....
Hi,
Thank you for your help everyone. These are the specs that I see for the Hitec 805BB:
Voltage Range 4.8V - 6.0V Current Drain - idle (4.8V) 8mA Current Drain - idle (6.0V) 8.7mA Current Drain - no-load (4.8V) 700mA Current Drain - no-load (6V) 830mA Requirements - high capacity receiver battery (at least 1200mAh).
Can't find any other specs for it. I also relooked at my power supply, it is 5VDC - 2.3A The jumper wire run will be about 2 inches. The servo and power supply will be in an enclosed case with an exhaust fan.
From the above answers, I might be good to go?
Any last bit of advice is truly appreciated.
@KillBill... Your current drain stats are for a servo with no load... I am assuming your servo is moving something? So it will "have" a load. And one stat is missing... Current drain at max torque (locked)... That will be over 3 amps... I think you will find you are going to be short of current.... Especially since most power supplies fail to provide the current that manufactures rate them for... If your ezb (which I assume is connected to your 5v power supply as well) starts to reset all the time it means your power supply isn't providing enough current for your project....
Lots of people have brought up "work bench" power supplies and trying to find ones that have enough amps for their projects. I use a 6V deep cycle RV battery that gives 232 Amps - problem solved ! My robot now has 29 - HS- 805 BB servos and 17 smaller ones on it. Also the wiring you are looking at will work OK.
Thanks for all your help.
I don't think you answered if the EZ-B is going to share the powwr supply. My assumption from your question was no. If not, be sure the EZ-B power and the servo power have a common ground or the control signals will, at best, be unreliable.