What is this?

[IdioticBuffoon]

I was playing around with this servo (Futaba S-148) that I got recently and accidently burned it. I opened it up and it seems that this red component took the brunt of it.

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Is it a capacitor? Usually capacitors have the value labeled with Farads like "5nF". I can't understand the numbers on this one. It says "22+ 10"?? I will try to get a replacement if I can figure out what this component exactly is.

Any help would be appreciated.

 

[herm0016]

that is a capicitor. you should be able to find one at a raido shack. not sure on the value, have to look up the number on the body. the cap is either a starting cap for the motor or more likly a power line filter.

 

[IdioticBuffoon]

Thanks man. I was suspecting it was a capacitor. Any idea what the value is? I'll take this to radio shack and see if they have something similar.

And BTW, any ideas on how to handle servos? So I don't burn any more of these?

Also, what kind of power supply should I use with it? Right now, I am using a NexxTech 6V DC, 1800mA supply. It's weird because when I put in a 10ohm resistor just to test the supply, I got a current of 1.45A instead of 0.6A. What could be wrong?

 

[IdioticBuffoon]

bump

 

[ribbon13]

22 and 10
so likely 22v 10mfd or 10v 22mfd.

perhaps you could contact Futaba for a schematic of specifics about the cap?

http://www.futaba-rc.com/service.html

 

[sdoodle787]

I'd check out digi-key, they likely have any part you would need to fix it. Can you be sure it is the only thing that went wrong, or is there another short on the board somewhere that caused the cap to burn? It doesn't seem like a cap should turn crispy like that without some good reason

 

[Skyhanger]

Originally posted by: IdioticBuffoon
Thanks man. I was suspecting it was a capacitor. Any idea what the value is? I'll take this to radio shack and see if they have something similar.

And BTW, any ideas on how to handle servos? So I don't burn any more of these?

Also, what kind of power supply should I use with it? Right now, I am using a NexxTech 6V DC, 1800mA supply. It's weird because when I put in a 10ohm resistor just to test the supply, I got a current of 1.45A instead of 0.6A. What could be wrong?

Most likely that your resistor is not rated to run at 9W (heck, i'll have trouble finding a 2W resistor) and it got burned out.

 

[ribbon13]

Originally posted by: Skyhanger

Originally posted by: IdioticBuffoon
Thanks man. I was suspecting it was a capacitor. Any idea what the value is? I'll take this to radio shack and see if they have something similar.

And BTW, any ideas on how to handle servos? So I don't burn any more of these?

Also, what kind of power supply should I use with it? Right now, I am using a NexxTech 6V DC, 1800mA supply. It's weird because when I put in a 10ohm resistor just to test the supply, I got a current of 1.45A instead of 0.6A. What could be wrong?

Most likely that your resistor is not rated to run at 9W (heck, i'll have trouble finding a 2W resistor) and it got burned out.

1/2 watt, 1 watt, 2 watt, 5 watt, 10 watt, and 20 watt are the common sizes, but 5w and above are usually wire wound ceramic.

 

[herm0016]

to properly handle a servo you need to use a control board, i use a programable bsx2 basic stamp chip with a devolpment board from parallax inc. otherwise look up the specs of your servo. some are 5v some are 12. the servo should only draw as much power as it needs. ie: if you hook it up to a battery with a 10A current rating then it will only draw a few milli amps. i have a custom nicad battery that is 4500mA at 7.2 volts that i use with my system. are you using the correct channels on the servo? don't use the control channel for voltage. i suspect the reason you blew up the servo is because you applied voltage to it and did not stop when the servo hit its hard stop. you MUST not keep the voltage on the servo when the motor is not moveing. you can also take the top off of the servo to file out the plastic stop, but then it is much harder to control absolute position.

 

[IdioticBuffoon]

Originally posted by: herm0016
to properly handle a servo you need to use a control board, i use a programable bsx2 basic stamp chip with a devolpment board from parallax inc. otherwise look up the specs of your servo. some are 5v some are 12. the servo should only draw as much power as it needs. ie: if you hook it up to a battery with a 10A current rating then it will only draw a few milli amps. i have a custom nicad battery that is 4500mA at 7.2 volts that i use with my system. are you using the correct channels on the servo? don't use the control channel for voltage. i suspect the reason you blew up the servo is because you applied voltage to it and did not stop when the servo hit its hard stop. you MUST not keep the voltage on the servo when the motor is not moveing. you can also take the top off of the servo to file out the plastic stop, but then it is much harder to control absolute position.

Thanks man. I'll try to keep this in mind.

 

[Zepper]

There is not enough room to put a lot of info on a small cap like that. There are web pages that explain the shorthand.

That is a 22 microFarad at 10V tantalum cap - the "+" is nearest to the Positive lead (could also be just a dot or a line depending on mfr and there may be another mark if tighter than +/-10% tolerance).
. Usually those won't blow unless put at reverse polarity or significant overvoltage - in which case they blow almost immediately, as you discovered... .

.bh.

 

[Jeff7]

You sure that it's not picofarads? I can't say I'm an expert....figured I'd say something though, just in case.

 

[Zepper]

Nope - it is definitely an epoxy dipped tantalum cap and they don't go that small - 0.1 uF is the smallest I've seen in that type.

.bh.

 

[edfcmc]

i know this is late, but for the archive searchers

digikey has it


for .81 cents

478-1874.

 

[JimPhelpsMI]

Hi, That's 22 MFD at 10 volts. Radio shack just may have one. I was in Radio Control in the days when you had to build radios and servos. Luck, Jim

 

[Snooper]

And that little Futaba S148 servo is a 4.8V servo. It doesn't pull much current, even at full load. Black is gound, red is positive, and white is signal. That signal line should have a pulse train on it. If my memory is correct, a 1.2ms wide positive pulse every 1/60 second should drive the servo to center. A wider pulse sends it one way and a narrower pulse sends it another. You DON'T want to just hook +V to the signal lead or you will fry more than just a cap.