3 lithiums plus voltage regulator?

2 lithiums = 7.4 volts, 3 lithiums = 11.1 volts. 7.7v is a bit low and flight may be marginal. 11.1v is a bit high and might fry stuff. How about running a 8v or 9v, 5A regulator. There are some low drop, fast response, high efficiency regulators available. My CC Phoenix esc will take up to 10 cells so that is not the problem.The JMP HF9-32 and tail motor will not be happy with 10v-11v. Anyone see any reasons not to give this a try? This might aslo apply to the picoboard. I do not run one so therefore don't know how much input voltage it will tolerate.

Actually, the 11 volts will work just fine. I use 3 qualcomms on my g-295 powered piccoboard with HF9-32 for the tail the tail. It works just fine and I doubt you will have problems. I had the same thought that 11 volts would be way to much for my speed controlers (both of them), but as you can see they hold up no problem.

[ 05 June 2002, 22:07: Message edited by: Jon h ]

Jon,
Thanks for quick response. Specs for HF9-32 call out 9.6v max. so that was why I was concerned. The other concern is tail motor not liking higher voltages. Maybe that just applies to the low freq. esc's. Any idea what your 3 Qualcom packs weigh? Thanks again.

I think that that 9.6 volts is a misprint. With the HF9 you do not need to worry about high voltage on the tail motors. It works like this;
all ESC's turn the motor on and off to regulate the speed of the motor. With low speed controlers
it would be like gunning your car to full speed and then slamming on the braks every 2 seconds to regulate its speed. This is why the picco board runs through so many motors. With a high speed controler it swiches so fast that the current to the motor doesn't jump up and down, it is regulated at one voltage. Because it takes a while for the current to drop to zero after power is removed we can turn it back on before it hits zero. Thus reducing those spikes that hurt our motors. Hope that made sense.

What does all this mean? Well no matter how high of voltage is applied to the ESC, it will regulate it to make it seem like there is the same voltage applied to the motor. So your tail motors will not wear out with 3 lithiums.

I think my packs weight 2.7 oz (if i remember right)

I have been running 3 cells, orion, 8 tooth, stock piccoboard now for around 40 hours flight time, same componants, no damage..not even a tail rotor, I have a hmp waiting to be installed after this tail motor dies, but it keeps on spinning. I don't know maybe it's the high rotor speed with my cf hornet blades..but no problems with this set-up...

picoants

p.s. I am running 18650 moli's between 20-24 minutes oge.

Cool, one less thing to worry about. [img]images/icons/smile.gif[/img] Picoants, any idea what your 3X18500 pack weighs?

[JJ]

My HF9-32 instructions say 5-9 cells (6v -10.8v)
This is likely to be a limit for electrical components inside the controller, or to limit the heat dissipated.