Capacitor connected to receiver? What does it benefit?
12-13-2001, 07:32 AM
#31
could i use the large cap from my cyclone???
12-14-2001, 12:07 AM
#32
Tech Regular
Depends whet you are doing with it. If you want to get rid of glitches then it does not help much because the large electrolytic capacitor works crap at such high frequencies. If you want to help your speedo to give enough peak current to the servo without making the voltage drop/fluctuate with the current then it's ok, although it might be a litle overkill.
I've put mine on the receiver battery terminal. Just soldered the cap to a spare connector directly so it's a straight plug-in plug-out.
I've put mine on the receiver battery terminal. Just soldered the cap to a spare connector directly so it's a straight plug-in plug-out.
12-14-2001, 01:33 AM
#33
Tech Adept
Jesse T: What numbers on the capacitor for the receiver?
12-14-2001, 02:35 AM
#34
Tech Adept
pic of the one yokomo sells:
12-30-2001, 09:32 PM
#35
My son and I cured a bad glitch by putting a 4800mfd 12 volt capacitor on the Futaba receiver. We just soldered the cap to an old servo lead (observing the correct polarity of course) and plugged it into the battery socket in the receiver. The glitch started when we installed a HS5925 servo. The Novak Duster 2 ESC we were using couldn't supply enough current to cover the servo's current spikes without the output voltage sagging. We just bought the cap from a local electronic supply for $2.00.
04-13-2006, 01:56 AM
#36
Where slot i must use to place the capacitor, the receiver 2ch only have ch1,ch2,batt slot.
04-13-2006, 02:15 AM
#37
Originally Posted by nino_pohan
Where slot i must use to place the capacitor, the receiver 2ch only have ch1,ch2,batt slot.
04-13-2006, 02:25 AM
#38
Originally Posted by sonneteer
The issue of intereference cannot only be blamed at the ESCs... the motor is actually the main cause of all evils, but the motor manufacturers are not doing much about it either.... the real problem is the receiver design, it is designed to receive signals, and at the same time it must reject random signals in forms of interference. This makes the receiver design very difficult and ultimately very expensive.
The manufacturers havent much to work on either.... they dont have an effective grounding as most cars are plastic or non conductive, so they cannot rely on a good earthing for the filters to work on, which can allow the filters to "drain" the spikes to earth properly.
We need weight reduction, so the receiver battery is eliminated, we want small size too! so physically the capacitors are the main problem as their values are realted to size....and there you are, you have a receiver drawing milliamps from a source there there will be a motor and ESC supplying square waves in tens of amperes! In this situation it is almost impossible to keep the power stable, the battery internal resistance also plays a part....
With some carbon fiber chassis the situation is even worse, teh chassis is noe fully conductive and therefore there can be a potential voltage at either end, andit also becomes charged....
I am currently working on a R/C grounding system to hopefully improve something....
on the manufacturer's side, I have noticed that motors are emitting more and more due to being over tuned and thus more arcing.... the ESC quality and reliability has improved, but sadly the radio system quality has suffered in the budget price range.
So investing in a good radio system is a good starting point I believe.
The manufacturers havent much to work on either.... they dont have an effective grounding as most cars are plastic or non conductive, so they cannot rely on a good earthing for the filters to work on, which can allow the filters to "drain" the spikes to earth properly.
We need weight reduction, so the receiver battery is eliminated, we want small size too! so physically the capacitors are the main problem as their values are realted to size....and there you are, you have a receiver drawing milliamps from a source there there will be a motor and ESC supplying square waves in tens of amperes! In this situation it is almost impossible to keep the power stable, the battery internal resistance also plays a part....
With some carbon fiber chassis the situation is even worse, teh chassis is noe fully conductive and therefore there can be a potential voltage at either end, andit also becomes charged....
I am currently working on a R/C grounding system to hopefully improve something....
on the manufacturer's side, I have noticed that motors are emitting more and more due to being over tuned and thus more arcing.... the ESC quality and reliability has improved, but sadly the radio system quality has suffered in the budget price range.
So investing in a good radio system is a good starting point I believe.
Ditto with motor capacitor, I think zero ohm means good capacitor ( I need somebody to confirm this ).
05-11-2006, 09:01 PM
#39
can i use the same size cap that is on the motor?
05-15-2006, 11:14 AM
#40
I fitted a Spektrum Voltage Protector into my Futaba receiver.
It's just an electrolytic 10v 4700uf cap.
The problem with BEC's on some of the ESC's is that the voltage is slightly lower (5.8v) than the rated voltage of the current crop of servo's, so if the servo requires that little extra it can cause the voltage to the receiver circuit to drop.
Although it may help with glitching the main reason for adding these among the people that I know is to remove the chances of a Personal Transponder missing a lap during one of the voltage 'drops'
The capacitor can fit into any available slot in the receiver.
Luckily I have a 3 channel receiver, so with my personal transponder and the cap all the slots are taken.
Skiddins
It's just an electrolytic 10v 4700uf cap.
The problem with BEC's on some of the ESC's is that the voltage is slightly lower (5.8v) than the rated voltage of the current crop of servo's, so if the servo requires that little extra it can cause the voltage to the receiver circuit to drop.
Although it may help with glitching the main reason for adding these among the people that I know is to remove the chances of a Personal Transponder missing a lap during one of the voltage 'drops'
The capacitor can fit into any available slot in the receiver.
Luckily I have a 3 channel receiver, so with my personal transponder and the cap all the slots are taken.
Skiddins
05-15-2006, 04:48 PM
#41
I agree with all posted.
The caps plugged into the receiver can help retain responsiveness from high torque or high speed servos, as well as help to eliminate receiver shut down's from insufficient voltage.
This is especially a problem using the Quatum Comp/comp 2 ESC's as they have a low output current (only 1.4 amps). Good servos can use that up alone.
And, to compound the problem, the regular Spektrum receivers are sensitive to this low current and will not operate properly WITHOUT a cap plugged into it. I found this out right when the Spektrum first came out. I could NOT get mine to work, then I tried the cap plugged into it and it worked fine.
The other alternative, if you are running a PT as well, is to construct a 6volt/2 amp regulated output device to power either the entire receiver/servo/PT system, or as I do, just power the servo. That way I know my servo is getting 6 volts, and plenty of current is available for it. And my spektrum runs fine off my BEC of my QC2 with the PT plugged into it. You could also use this device to power the personal transponder.
The caps plugged into the receiver can help retain responsiveness from high torque or high speed servos, as well as help to eliminate receiver shut down's from insufficient voltage.
This is especially a problem using the Quatum Comp/comp 2 ESC's as they have a low output current (only 1.4 amps). Good servos can use that up alone.
And, to compound the problem, the regular Spektrum receivers are sensitive to this low current and will not operate properly WITHOUT a cap plugged into it. I found this out right when the Spektrum first came out. I could NOT get mine to work, then I tried the cap plugged into it and it worked fine.
The other alternative, if you are running a PT as well, is to construct a 6volt/2 amp regulated output device to power either the entire receiver/servo/PT system, or as I do, just power the servo. That way I know my servo is getting 6 volts, and plenty of current is available for it. And my spektrum runs fine off my BEC of my QC2 with the PT plugged into it. You could also use this device to power the personal transponder.
05-15-2006, 09:01 PM
#43
hey guys i have only just got my new radio(helios with spektrum) and a new servo (bluebird 6v high speed) and am running a nosram hawk reverse and whenever i turn to near full turn or full turn my car goes full speed and stays turning in one direction,it only does this for maybe a second or 2 and then works finw until i do a big fast turn again...
would it help if a 4700uf 10v cap was plugged into the batt spot on my spektrum reciever?
would it help if a 4700uf 10v cap was plugged into the batt spot on my spektrum reciever?
05-16-2006, 02:29 PM
#44
Tech Adept
here's what i think whats wrong.
if your servo is near the end point of itself it could be later then the end point of your car, so the servo keeps on puching your steering rods while the steering geometry cant swing further. therefor the servo is holded in a single position still wanting to get to its end point and therefore draining lots of amps your esc maybe cant or wont give or your servo shuts down as voltage becomes to low. shuts down, and when voltage recovers after your servo stopped asking for more amps and volts it starts up again, recieves the signal and does what you say it should do.
it Could be this and can easily be solved with setting your epa settings. loads of people who can help you with that on this forum i guess. it should be pretty easy to do.
lemme know if its the epa settings
Mark
if your servo is near the end point of itself it could be later then the end point of your car, so the servo keeps on puching your steering rods while the steering geometry cant swing further. therefor the servo is holded in a single position still wanting to get to its end point and therefore draining lots of amps your esc maybe cant or wont give or your servo shuts down as voltage becomes to low. shuts down, and when voltage recovers after your servo stopped asking for more amps and volts it starts up again, recieves the signal and does what you say it should do.
it Could be this and can easily be solved with setting your epa settings. loads of people who can help you with that on this forum i guess. it should be pretty easy to do.
lemme know if its the epa settings
Mark
05-16-2006, 04:01 PM
#45
i ad my epa set to the furthest point of my steering so not my servo