I have been using Hitec 785HB sail winches which draw 285ma no load operating. I recently modified a Hitec 805 BB into a winch. It draws 830ma no load operating. This is making me wonder about my wiring harness. I use a “Y” cable to power the servo directly but my concern is the connectors, the switch and the wire. Should I be upgrading my stuff? I use alkaline batteries(for now), is the spring clip battery box a concern? Any thoughts or observations?
Thanks
Don
One figure I’d like to see quoted on servo specs is current draw at their rated torque or at least stall current. The figures would take a lot of the guess work out of calculating battery capacity and also your question about connectors.
In any event, using 5 cells virtually makes a soldered battery pack a necessity.
Hitech publishes the current drain of SOME of it’s servos. I usually check the servocity.com site. My digital high torque servo draws up to 4.2 amps (6v) at stall! It is probably close to stalled in some sailing situations, so I have a 7.2v, 2300mah nano phosphate battery pack(DeWalt cells) with a CC BEC set to knock the voltage to 6v as a precaution. It can provide 5A.
Hi Don,
The no-load draw is not the important number for sizing. What is important is peak at/near stall.
The wires on the servo should be sized for its current draw as supplied. Use a Y with at least that wire size, or bigger between the battery and servo.
I use a 10 amp sub-miniture toggle switch (SPST on-off).
I have read that the battery box connections are not good enough. The recommendation is a soldered battery pack.
If you really want to know how much current you are drawing with your set up under different conditions, use an amp meter.
You can use either a clamp on meter or just a small analog meter in series. You can buy small analog amp meters(1-10amps) cheap from most electronic supply places.