Your onboard RX pack voltage monitoring system
02-06-2006, 10:59 PM
#1
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Your onboard RX pack voltage monitoring system
I have a few RX namely Hitec FM and Futaba PCM and uses Hobbico Voltwatch2 for my plane.
I flown extensively on the Futaba PCM rx with the onboard Hobbico Voltwatch2. When I move all my servo, the voltage will drop (obviously as the batt is being loaded with servo movement) and it will hit yellow range with the green lighted up as well. But it will return to full green when servo movement stop and never hit the red zone.
Recently I swapped the Futaba PCM rx with my Hitec RX ane even with same plane and same servo, the voltage drop seem to be more, all the way to red briefly before returning to green. This is with same batt pack and same servo and same plane. Just different rx from Futaba PCM to Hitec FM!!! The rx pack is fully charged!!!
I tried with other Hitec rx, it does the same. It hit the red!!!!
Whats give? All these time I flown the hitec rx on my other smaller plane which I never use voltwatch2. Now that I'm getting another big plane and as I setting them up, I discover this.
These Hitec RX have flown in some other 60size plane before with no crashes or issues even on 4-6 servo setup. Never get a glitch prior this.
BTW, it will also hit red even with just 1 servo movement.....huh!!!???? I'm out of wit here...
I flown extensively on the Futaba PCM rx with the onboard Hobbico Voltwatch2. When I move all my servo, the voltage will drop (obviously as the batt is being loaded with servo movement) and it will hit yellow range with the green lighted up as well. But it will return to full green when servo movement stop and never hit the red zone.
Recently I swapped the Futaba PCM rx with my Hitec RX ane even with same plane and same servo, the voltage drop seem to be more, all the way to red briefly before returning to green. This is with same batt pack and same servo and same plane. Just different rx from Futaba PCM to Hitec FM!!! The rx pack is fully charged!!!
I tried with other Hitec rx, it does the same. It hit the red!!!!
Whats give? All these time I flown the hitec rx on my other smaller plane which I never use voltwatch2. Now that I'm getting another big plane and as I setting them up, I discover this.
These Hitec RX have flown in some other 60size plane before with no crashes or issues even on 4-6 servo setup. Never get a glitch prior this.
BTW, it will also hit red even with just 1 servo movement.....huh!!!???? I'm out of wit here...
02-07-2006, 01:08 PM
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RE: Your onboard RX pack voltage monitoring system
It could be caused by resistance from the on-off switch causing a voltage drop.
Just for a quick test, try plugging your battery directly into the receiver and see if your problem goes away.
If the switch is the problem, Futaba makes a nice heavy duty switch that should help.
It is a much better switch for larger planes.
Tower has it but it's hard to find on their web site.
http://www2.towerhobbies.com/cgi-bin...?&I=LXXA49&P=7
Just for a quick test, try plugging your battery directly into the receiver and see if your problem goes away.
If the switch is the problem, Futaba makes a nice heavy duty switch that should help.
It is a much better switch for larger planes.
Tower has it but it's hard to find on their web site.
http://www2.towerhobbies.com/cgi-bin...?&I=LXXA49&P=7
02-08-2006, 12:40 PM
#3
My Feedback: (2)
RE: Your onboard RX pack voltage monitoring system
Perhaps the Hitec Rx is able to source more current than the Futaba Rx(possibly because the Hitec uses different semiconductors) and therefore the peak current draw during servo movements is higher.
Another possiblity... the Hitec Rx has higher internal resistance in the power bus conductors of its circuit board?
Another possiblity... the Hitec Rx has higher internal resistance in the power bus conductors of its circuit board?
