Servo draw current
04-29-2013, 01:02 AM
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Servo draw current
What would be the approx current draw of 1 servo in a Rap 30 , mild 3D ,
I will times it by 5 to put a load on my Rx battery
for checking purposes ,
thanks so much
04-29-2013, 04:08 AM
#2
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RE: Servo draw current
ORIGINAL: 123Cat
What would be the approx current draw of 1 servo in a Rap 30 , mild 3D ,
I will times it by 5 to put a load on my Rx battery
for checking purposes ,
thanks so much
What would be the approx current draw of 1 servo in a Rap 30 , mild 3D ,
I will times it by 5 to put a load on my Rx battery
for checking purposes ,
thanks so much
04-29-2013, 07:55 AM
#3
Senior Member
RE: Servo draw current
It is doubtful that you will get an accurate peak current reading on any analog or digital MM unless it is capable of RMS measurements with a peak capture feature as the initial current surge as a servo is commanded to move is usually quite high, maybe as much as 3 amperes for a few milliseconds. If the servo gets stalled out, this current can be even higher. Your typical meter should read the average current reasonably well though.
04-29-2013, 08:34 AM
#4
RE: Servo draw current
What a way things have changed as back in the old days it was pretty much the norm for radios sets to be supplied with 500mA Nicad battery packs for both Tx and Rx and we would fly all day and only had the little green/orange/red meter on the Tx as a reference to guide us. Plus we used a std servos to fly just about anything, agreed the models were not a big as they are now, but now everyone seems to think that they need a 200 oz. plus servo.
04-30-2013, 07:22 AM
#6
RE: Servo draw current
I'm not sure I understand what you are trying to accomplish.
My advise to put a 0.5amp load with a loaded voltmeter was to determine fly / no-fly battery status quickly. You do not need the full load of all five servos. That technique has been working for years. With a 2000mah battery and standard servos, you should be able to fly/hover almost all day long. If you have standard equipment you will notice the servos starting to slow down way before you loose control of the aircraft.
If you require further information, we will need exact model numbers of all of your servos, and a video of your flying style, to try to approximate a guess answer. The best answer in that scenario so far is this one:
Rafael
My advise to put a 0.5amp load with a loaded voltmeter was to determine fly / no-fly battery status quickly. You do not need the full load of all five servos. That technique has been working for years. With a 2000mah battery and standard servos, you should be able to fly/hover almost all day long. If you have standard equipment you will notice the servos starting to slow down way before you loose control of the aircraft.
If you require further information, we will need exact model numbers of all of your servos, and a video of your flying style, to try to approximate a guess answer. The best answer in that scenario so far is this one:
BuschBarber
Purchase or borrow a Hangar9 Current Meter and connect it between the servo and the Rx. The amount of current depends upon a number of factors including the model servo and the load on it.
Purchase or borrow a Hangar9 Current Meter and connect it between the servo and the Rx. The amount of current depends upon a number of factors including the model servo and the load on it.
04-30-2013, 07:54 AM
#7
My Feedback: (2)
RE: Servo draw current
ORIGINAL: Rafael23cc
I'm not sure I understand what you are trying to accomplish.
My advise to put a 0.5amp load with a loaded voltmeter was to determine fly / no-fly battery status quickly. You do not need the full load of all five servos. That technique has been working for years. With a 2000mah battery and standard servos, you should be able to fly/hover almost all day long. If you have standard equipment you will notice the servos starting to slow down way before you loose control of the aircraft.
If you require further information, we will need exact model numbers of all of your servos, and a video of your flying style, to try to approximate a guess answer. The best answer in that scenario so far is this one:
Rafael
I'm not sure I understand what you are trying to accomplish.
My advise to put a 0.5amp load with a loaded voltmeter was to determine fly / no-fly battery status quickly. You do not need the full load of all five servos. That technique has been working for years. With a 2000mah battery and standard servos, you should be able to fly/hover almost all day long. If you have standard equipment you will notice the servos starting to slow down way before you loose control of the aircraft.
If you require further information, we will need exact model numbers of all of your servos, and a video of your flying style, to try to approximate a guess answer. The best answer in that scenario so far is this one:
BuschBarber
Purchase or borrow a Hangar9 Current Meter and connect it between the servo and the Rx. The amount of current depends upon a number of factors including the model servo and the load on it.
Purchase or borrow a Hangar9 Current Meter and connect it between the servo and the Rx. The amount of current depends upon a number of factors including the model servo and the load on it.
I have always estimated the combined current draw of all servos and based my Rx battery capacity accordingly.
04-30-2013, 10:23 AM
#8
RE: Servo draw current
ORIGINAL: BuschBarber
Years ago, with 72Mhz radios, there were times when the Rx battery voltage would drop to a point where the servos would become sluggish but the Rx was still operating. I have never seen this with 2.4 radios. You get a Brownout before the servos get slow.
I have always estimated the combined current draw of all servos and based my Rx battery capacity accordingly.
ORIGINAL: Rafael23cc
I'm not sure I understand what you are trying to accomplish.
My advise to put a 0.5amp load with a loaded voltmeter was to determine fly / no-fly battery status quickly. You do not need the full load of all five servos. That technique has been working for years. With a 2000mah battery and standard servos, you should be able to fly/hover almost all day long. If you have standard equipment you will notice the servos starting to slow down way before you loose control of the aircraft.
If you require further information, we will need exact model numbers of all of your servos, and a video of your flying style, to try to approximate a guess answer. The best answer in that scenario so far is this one:
Rafael
I'm not sure I understand what you are trying to accomplish.
My advise to put a 0.5amp load with a loaded voltmeter was to determine fly / no-fly battery status quickly. You do not need the full load of all five servos. That technique has been working for years. With a 2000mah battery and standard servos, you should be able to fly/hover almost all day long. If you have standard equipment you will notice the servos starting to slow down way before you loose control of the aircraft.
If you require further information, we will need exact model numbers of all of your servos, and a video of your flying style, to try to approximate a guess answer. The best answer in that scenario so far is this one:
BuschBarber
Purchase or borrow a Hangar9 Current Meter and connect it between the servo and the Rx. The amount of current depends upon a number of factors including the model servo and the load on it.
Purchase or borrow a Hangar9 Current Meter and connect it between the servo and the Rx. The amount of current depends upon a number of factors including the model servo and the load on it.
I have always estimated the combined current draw of all servos and based my Rx battery capacity accordingly.
That works for me too.
04-30-2013, 10:49 AM
#9
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RE: Servo draw current
Here is one way to be sure. If you have a charger that shows ma in. Fly twice and time the flights. Re=charge and record the ma in. Fly 3 times and record the time. Re-charge and record the ma in. The do a average divided by the ma of the battery and that is the number of flights you'll get.
You can't do a load test on the ground. The load will be higher in the air.
If you are using nicad. if you see 4.8 on a 4 cell or 6v on a 5 cell re-charge Dennis
You can't do a load test on the ground. The load will be higher in the air.
If you are using nicad. if you see 4.8 on a 4 cell or 6v on a 5 cell re-charge Dennis
04-30-2013, 11:13 AM
#10
My Feedback: (2)
RE: Servo draw current
Since I switched to Lithium Rx and Tx batteries, I know that they will hold their charge for months and that they can be recharged in minutes. There is just no comparison to what you have to go through with NiCad/NiMh batteries. I never get caught with an inadequately charged pack. No False Peaking, no Self Discharge, and no Overnight Charging. With a good Lithium charger like the FMA 10S, I can charge up to two 5S packs at a time, for example. I have 110% faith in their Safe operation.
04-30-2013, 01:26 PM
#13
RE: Servo draw current
I must have done something right, because the poor guy got only 5 replies in over 24 hours, and my simple commentary got 6 replies in less than 8 hours.
Answer to him, not to me. Been doing this for over 20 years. We still do not know what he has installed in his aircraft, to be able to even take a guess, so we are all taking stabs in the dark. We don't even know if he's flying 72mhz, 2.4ghz or something totally different. All I know is that he is located in Australia.
Just to be fair, does anybody have a link to a published chart of servo current draw? Or is this the best reply we've gotten to date?
Rafael
Answer to him, not to me. Been doing this for over 20 years. We still do not know what he has installed in his aircraft, to be able to even take a guess, so we are all taking stabs in the dark. We don't even know if he's flying 72mhz, 2.4ghz or something totally different. All I know is that he is located in Australia.
Just to be fair, does anybody have a link to a published chart of servo current draw? Or is this the best reply we've gotten to date?
DadsToysBG
Here is one way to be sure. If you have a charger that shows ma in. Fly twice and time the flights. Re=charge and record the ma in. Fly 3 times and record the time. Re-charge and record the ma in. The do a average divided by the ma of the battery and that is the number of flights you'll get.
Here is one way to be sure. If you have a charger that shows ma in. Fly twice and time the flights. Re=charge and record the ma in. Fly 3 times and record the time. Re-charge and record the ma in. The do a average divided by the ma of the battery and that is the number of flights you'll get.
05-01-2013, 05:00 PM
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RE: Servo draw current
Sorry , I was away
Its a Rap 30 for mild to roughish 3D ,,,Analoge servos 401 Gyro,,, 36 MHZ
Thanks I will put a 1/2 amp load on and cease at 4.8 Volts
Who knows what the flight current draw is, it can spike high in a failed Tic Toc like I do
or panic pullout
Its a guessing game
Its a Rap 30 for mild to roughish 3D ,,,Analoge servos 401 Gyro,,, 36 MHZ
Thanks I will put a 1/2 amp load on and cease at 4.8 Volts
Who knows what the flight current draw is, it can spike high in a failed Tic Toc like I do
or panic pullout
Its a guessing game
05-02-2013, 03:18 AM
#16
Senior Member
RE: Servo draw current
If you are only drawing down to 4.8 volts, you are not even using 1/2 the capacity of your Nixx battery. You can safely go down to 1.1 volt per cell. Even then you will have 1/10 the power still remaining in the cells.
05-02-2013, 06:43 AM
#18
RE: Servo draw current
ORIGINAL: 123Cat
Its a Rap 30 for mild to roughish 3D ,,,Analoge servos 401 Gyro,,, 36 MHZ
Thanks I will put a 1/2 amp load on and cease at 4.8 Volts
Its a Rap 30 for mild to roughish 3D ,,,Analoge servos 401 Gyro,,, 36 MHZ
Thanks I will put a 1/2 amp load on and cease at 4.8 Volts
You should still use the suggestion of averaging the flights and the current used per flight to determine how many flights your battery is capable of sustaining. On top of that check battery "health" by checking the voltage between flights. Using a 0.5amp load, I would stop flying between 4.6 and 4.8 volts depending on equipment and how hard I fly. I have not used Nicds in years. All my birds have liion batteries now.
Rafael
05-02-2013, 11:57 PM
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RE: Servo draw current
I think he is worried about the Amps used in his flight and not the mAh.
Start with your battery freshly charged, do 1, 10 minute flight including your tic toc's. Charge battery and record mAh used. Take that number and multiply by 6 to get the amount of amps used during 1 hour of flying. You now have your average amp use. So if you put back 200 mAh in 10 minutes then you would use 1.2 amps in an hour and that is also your average amp draw.
I fly an EF 50cc bird and even flying the crap out of it I don't put back in any more then 1900 mAh in an hour. So 1.9 amp draw average. Don't see how the claims of 50 amps being pulled from high torque servo's during high G stuff can be true with those numbers.
Start with your battery freshly charged, do 1, 10 minute flight including your tic toc's. Charge battery and record mAh used. Take that number and multiply by 6 to get the amount of amps used during 1 hour of flying. You now have your average amp use. So if you put back 200 mAh in 10 minutes then you would use 1.2 amps in an hour and that is also your average amp draw.
I fly an EF 50cc bird and even flying the crap out of it I don't put back in any more then 1900 mAh in an hour. So 1.9 amp draw average. Don't see how the claims of 50 amps being pulled from high torque servo's during high G stuff can be true with those numbers.
05-03-2013, 10:15 PM
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RE: Servo draw current
I just want to stop flying when my Eneloop 2000 pak cant deliver any more
, Ive got a 5 watt 39 OHM resistor across my DVM
and Im seeing 5.42 V without resistor and 5.39 v with resistor so its putting on a little load ,
I will go with that down to about 4.6 V
thanks a lot
, Ive got a 5 watt 39 OHM resistor across my DVM
and Im seeing 5.42 V without resistor and 5.39 v with resistor so its putting on a little load ,
I will go with that down to about 4.6 V
thanks a lot
05-03-2013, 10:21 PM
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RE: Servo draw current
I dont know what the minimum operating voltage of my PCM 9 ch NER 649S Rx is
and how fast it recovers after getting under voltage , in relation to the fancy 2.4 Rx's
I guess they are about the same
I dont plan on getting to that point
and how fast it recovers after getting under voltage , in relation to the fancy 2.4 Rx's
I guess they are about the same
I dont plan on getting to that point
05-06-2013, 08:07 AM
#22
RE: Servo draw current
ORIGINAL: 123Cat
I dont know what the minimum operating voltage of my PCM 9 ch NER 649S Rx is
and how fast it recovers after getting under voltage , in relation to the fancy 2.4 Rx's
I guess they are about the same
I dont plan on getting to that point
I dont know what the minimum operating voltage of my PCM 9 ch NER 649S Rx is
and how fast it recovers after getting under voltage , in relation to the fancy 2.4 Rx's
I guess they are about the same
I dont plan on getting to that point
With the new 2.4 receivers, it is like an electrical surge for a computer, if you have one, you have to wait until it reboots. And the servos themselves were probably the cause of the electric surge. As far as I understand, most manufacturers have a fast reboot protocol nowadays. That was a problem with early 2.4 systems and the people not used to them. If you look back in the archives a few years back you will see the reports of airplanes falling out if the sky. We all know better now.
Rafael
