Max servo amperage?

[JIves]

Of course this is a function of the power supply as well (using a 2amp now, but could upgrade if needed) but I'm thinking of going with this servo: http://www.servocity.com/html/hs-645mg_ultra_torque.html#.VAyWmc6CPCQ it draws 450mA with no load. I don't anticipate the load being terribly high but I'm putting a pretty long arm on it to give me full range control off Primo bottom vent. I'm controlling it fine right now with a towerpro mg90s but I fear if I put too long an arm on that servo it may bog down a bit. Frankly I also tend to want to over engineer a bit just to ensure no issues during long cooks. I did a cook a pork butt with the small servo just fine but i want to have the full range of the bottom vent for maximum range control.

Is there an amperage limit on the board itself in terms of servo current draw that I should be aware of?

 

[Bryan Mayland]

There's no hard limit, and the 5V power comes directly from our onboard regulator which powers the Pi and everything. That's limited to 1.5A max.

Even the cheapo MG90 servos pull up to an amp when there's a little resistance, so you have to worry about browning out the Pi. Worst case scenario, you can run the servo on it's own 5V power supply I think.

 

[JIves]

Update on this, I tested today with the regular size Hitec HS-465MG servo. This servo and the linkage I'm using gives me very wide range control over the bottom vent on my primo. The Pi did brown out once during the cook but only once.

I have parts for another kit and I may actually consider upping the 5v power converter to something more along these lines: http://www.mouser.com/ProductDetail...=sGAEpiMZZMt6Q9lZSPl3Rfy0vJBOBJmszVAisGeYjCg= Datasheet: http://www.mouser.com/ds/2/167/NSR003A0X-10957.pdf

It can do 3amp output, likely will step up from a 2 amp to a 3 amp 12 volt supply as well. Another option is that I may do this as a "parasite" board and use it right off the main 12v supply and tap in that way.