Good day
I have a little back ground in electronics. I have a small dirt devil vaccume cleaner. There is a 12v dc motor that powers the beater bar. After about 5 min the motor stops. I have found a small I think ceramic capacitor (round and flat) that heats up really hot. If I measure just before the cap I get my 12v so Im assuming that for what ever reason its heating up its the cause of my problem. There are no markings on it how would I go about replacing it. Can I use any kind a cap for replacement for eg I have a electrolytic Cap at 16v 100uf
Thanks

 

Ceramic capacitors don't usually fail without electrical or mechanical over stress. What is near the cap that could be causing it to get hot?

It could be a PTC fuse that looks a lot like a ceramic disc capacitor. That would indicate an overload condition; likely caused by the motor. When the fuse cools, it will conduct again.

 

Does this help

 

Hello,

When the device is in series with the motor, it is likely a polyfuse, as suggested.

Bertus

 

UF135 is a 1.35A PolySwitch resettable fuse, not a capacitor.

 

Thanks guys.
So I guess that the motor is drawing a little more current than it should. Do I replace the motor. It seems to run fine for long periods of time when connected to a 12v battery or can I get a larger ratted resettable fuse (30v 1.85A)

 

A couple of possible issues:

1. Too much friction. Motor drawing too much current. A better battery could solve that. Too much friction can also wear out the brushes.

2. Bad batteries. What's the battery chemistry? What is the arrangement? Measure each cell voltage: e.g. use a sewing needle to puncture the heat shrink. How old are the batteries? With some food guesses, you can replace the pack.

I have a 4-station vtech phone that originally came with wimpy Ni-Cd 600 mA battery packs for about $20.00 a pack. I can get Ni-MH packs at 4x the capacity for the same price with no connector and an integral polyfuse. The Ni-mH replaces the Ni-Cd with any charger changes.
Lifetime is now reduced due to the way we use the phones now, but I've gotten 7 years of life when used like they are supposed to be, Always on charge and lifted for the duration of a short conversation.

Two phones are swapped in typically 16 h charge /8 hour off base sequence every day. Those lasted about a year.

Incidently, the base and answering machine are powered by a UPS.

 

If I use an amp meter the motor draws .65 amps. When I drag it over the carpet its anywhere from .9 to 1.19. Do the Polyswitches ever go bad. I think I will order the 30v 1.85a polyswitch on Ebay.

Sorry KeepItSimpleStupid I should have said when I remove the motor and use a 12v battery I have. The vac runs on 120v and has a circuit to reduce the voltage to 12v dc

 

I think I will order the 30v 1.85a polyswitch on Ebay.

Do yourself a favor and buy from a reputable source.

Amazon, eBay, and AliExpress are sources of cheap parts of unknown authenticity. If you buy from a reputable source, they'll stake their reputation on the authenticity of what they sell.

There are undoubtedly reputable sellers on eBay. The key is to find them. If someone is selling odd lots of parts, you have a pretty good chance of getting something that is genuine. If they have a store or frequently list the same components, it's more likely they're going to be fake. Especially if it ships from China or, more recently, Cambodia.

 

Thanks Guys. Need a little info on a new one
I found one (not on ebay)
These are the specs
Holding current 1.85 amp
tripping Current 3.7 amp
voltage 30 volts
I dont understand what the difference is with holding current and tripping current

 

When it comes to fuses and breakers, never go over the original rating. You're just asking for trouble in the form of "Lack of circuit protection" and "Potential fire".

 

Need a little info on a new one
I found one (not on ebay)
These are the specs
Holding current 1.85 amp
tripping Current 3.7 amp
voltage 30 volts
I dont understand what the difference is with holding current and tripping current

The replacement fuse needs to have a holding current of 1.35A.

 

Wasn't going to say it - - - but here it is: Is there hair wrapped around the brush bearings or the motor bearings?

 

A couple of drops of oil on the shaft where it can work its way into the bearings might help. On the other hand, it might be time for a new motor.

Per @Tonyr1084, the fuse is there to protect the wiring and the motor. putting in a larger fuse might extend the life a little but would not solve the problem, and maybe even make things worse.

 

If it had operated satisfactorily earlier in its existence, then the solution must be mechanical. Nothing with regard to any part of the electrical circuitry, other than perhaps a problem in the motor itself, is going to cause the motor current to rise. If the batteries are "weak" the current will go down, not up.

 

Good day
I have a little back ground in electronics. I have a small dirt devil vaccume cleaner. There is a 12v dc motor that powers the beater bar. After about 5 min the motor stops. I have found a small I think ceramic capacitor (round and flat) that heats up really hot. If I measure just before the cap I get my 12v so Im assuming that for what ever reason its heating up its the cause of my problem. There are no markings on it how would I go about replacing it. Can I use any kind a cap for replacement for eg I have a electrolytic Cap at 16v 100uf
Thanks

Certain other components are similar in appearance to ceramic discs, so you have to look carefully what you got.

Most ceramic dielectrics are lossy at RF, and noise from knackered brushes could cause trouble if extreme. Back emf from the motor windings can also be a source of trouble. Ceramics can fracture and leakage/tracking can develop in the fissures - this often manefests as a short, but it doesn't sound like that happened (yet).

Ceramic disks usually have *SOME* sort of markings - MOVs and PTC/Polyfuses fairly often don't.

 

Thanks guys
The vac is only 10 months old so im going to see if I can go the warrenty route
Have a good Holiday Season

 

Warranty or not - did you check to see if something was wrapped around either the motor spindle or the beater bar / brush?

Wife was just complaining the other day her vacuum wouldn't pick up. The bag was full. AND the hose was clogged. Vacuums don't pick up forever without a little TLC.

 

Been there, seen it.

It was a couple of weeks into January. Someone was tossing out a house vac that wouldn't suck.
You guessed it. The hose was completely clogged with Xmas tree pine needles. Just needed a broom stick up the hose to clean in out.

 

Been there, seen it.

It was a couple of weeks into January. Someone was tossing out a house vac that wouldn't suck.
You guessed it. The hose was completely clogged with Xmas tree pine needles. Just needed a broom stick up the hose to clean in out.

I'm sure lots of us are hoping to shove a broomstick up the hose this festive season...……...