battery voltage drop capacitor - please clarify
02-22-2008, 01:11 PM
#1
Member
Thread Starter
Join Date: Aug 2005
Location: conwyuk, UNITED KINGDOM
Posts: 41
Likes: 0
Received 0 Likes
on
0 Posts
battery voltage drop capacitor - please clarify
Some peeps are saying that the large value (1000uf ) electrolytic capacitor which is marketed as an extra safeguard against brief voltage transient drops are useless in an aircraft setup, and they are ONLY useable in ground based sets. If this is true...then please explain why ?
Surely the principle is simply that of the capacitor providing a short buffer voltage in the event of a battery drop...and this could happen in any setup? I know it is not designed as a substitute for an insufficient capacity battery...but why have them at all then ?
Surely the principle is simply that of the capacitor providing a short buffer voltage in the event of a battery drop...and this could happen in any setup? I know it is not designed as a substitute for an insufficient capacity battery...but why have them at all then ?
02-25-2008, 09:16 AM
#2
RE: battery voltage drop capacitor - please clarify
The Spektrum voltage protector is for 1/12 scale cars that use a 4 cell pack to power the ESC and generally the output of the BEC is low, so the voltage protector helps prevent power loss. This is ONLY for 1/12 scale electric cars, it won't do anything in any other applications.
02-25-2008, 02:14 PM
#3
Member
Thread Starter
Join Date: Aug 2005
Location: conwyuk, UNITED KINGDOM
Posts: 41
Likes: 0
Received 0 Likes
on
0 Posts
RE: battery voltage drop capacitor - please clarify
Thanks Danny...but this does not explain WHY it doesnt do anything in a aircraft, which MAY also have a low power BEC supply.
03-14-2008, 01:48 AM
#4
Join Date: Oct 2006
Location: Grand Paririe,
TX
Posts: 188
Likes: 0
Received 0 Likes
on
0 Posts
RE: battery voltage drop capacitor - please clarify
Explanation:
In anything with a Regulator BEFORE the reciver a capicator would deffinetely help otherwise it would really do nothing.
Why:
A regulator isolates the receiver from the power, So if you have suffivent power going to the regulator but the servos for example draw the battery too low for a second the regulator wont allow the draw friom the servos to drain the capicator.
A reasonable capicator could power the receiver for several to many seconds to avoid a reboot.
IF JR/Spektrum had put a connector for a capicator on the receiver that connected AFTER the internal regulator but before the reciever part a capicator would function very nicely! Maybe why they did do that is because it might require a second internal regulator, One thing i also think would work, a diode such as a 1N4001 to isolate the reciever power from the batteries, it would allow power to the reciever but not allow it reversed so THEN a capicator would work nicely plugged into another channel but for this to work the servos power would have to come directly from the main battery, a 1N4001 would easily pass enough power to run the receiver but would fail driving servos anyway, the servos have to be isolated from the receiver .
I fly electrics and gas and nitro in Helis and planes and gliders and im SO sold on my x9303 i could dance, Ive been totally 2.4 for around 8 months with ZERO problems.
Now with all that said, ANY computer will reboot if not given enough voltage, the reason for this is because with a computer you have data in digital format, 1's and 0's, when power gets below what can happen is a 1 might turn into a 0 or visa versa, If that happens you can expect ANYTHING.
With Analog type recievers that dont have computers there nothing to get jumbled, as power goes down you loose range and selectivity but soon as power is back up you have it right back. With the computer stuff the problem is the split second low voltage tells the unit to reset and it should.
Bottom line is ANY computer has to have proper power, I do feel JR could have handled this possibility better but also they stae power requirements too, now i will NEVER understand why they sell units with 4 Cell packs.
In anything with a Regulator BEFORE the reciver a capicator would deffinetely help otherwise it would really do nothing.
Why:
A regulator isolates the receiver from the power, So if you have suffivent power going to the regulator but the servos for example draw the battery too low for a second the regulator wont allow the draw friom the servos to drain the capicator.
A reasonable capicator could power the receiver for several to many seconds to avoid a reboot.
IF JR/Spektrum had put a connector for a capicator on the receiver that connected AFTER the internal regulator but before the reciever part a capicator would function very nicely! Maybe why they did do that is because it might require a second internal regulator, One thing i also think would work, a diode such as a 1N4001 to isolate the reciever power from the batteries, it would allow power to the reciever but not allow it reversed so THEN a capicator would work nicely plugged into another channel but for this to work the servos power would have to come directly from the main battery, a 1N4001 would easily pass enough power to run the receiver but would fail driving servos anyway, the servos have to be isolated from the receiver .
I fly electrics and gas and nitro in Helis and planes and gliders and im SO sold on my x9303 i could dance, Ive been totally 2.4 for around 8 months with ZERO problems.
Now with all that said, ANY computer will reboot if not given enough voltage, the reason for this is because with a computer you have data in digital format, 1's and 0's, when power gets below what can happen is a 1 might turn into a 0 or visa versa, If that happens you can expect ANYTHING.
With Analog type recievers that dont have computers there nothing to get jumbled, as power goes down you loose range and selectivity but soon as power is back up you have it right back. With the computer stuff the problem is the split second low voltage tells the unit to reset and it should.
Bottom line is ANY computer has to have proper power, I do feel JR could have handled this possibility better but also they stae power requirements too, now i will NEVER understand why they sell units with 4 Cell packs.
