Safely discharging a capacitor

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Probably, but I'm not at the OP's house to take a look and be certain this is the case, and as the symptoms are classic signs of worn brushes, I thought I'd mention it in case.
The rest of my advice about looking for bad connections before replacing components is perfectly valid as well.
Dave
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How many tumble driers use brushed motors?
How many brushed motors also have a capacitor?
Now this assumes that it _is_ a capacitor of course. If it does have a brushed motor, I wouldn't be surprised if it had a line filter instead and these can look very similar to capacitors.
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Andy Dingley wrote:

I don't know, never had one apart, but I assumed they all did. Every washing machine I've ever repaired had a brush motor, why would they use induction on a tumble fryer as a matter of interest?
Dave
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On Thu, 22 Dec 2005 10:12:06 GMT, "david lang"

You use induction motors whenever you can - they're quieter (this is a domestic appliance after all) and they're cheaper. The advantage of the brushed motor is that they have much higher torque at low speeds or when stalled (why they appear on power tools) and they're also more easily controllable for variable speeds etc. There's a lot of things a washing machine does that a tumble drier just doesn't need.
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Andy Dingley wrote:

Odd. The only experience I have is with high pressure cleaners. The el cheapo DIY jobbys have brush motors which make a terrible screaming noise - but they use them to reduce costs.

I can see the logic in that, but I've always assumed (from my HPC experiences) that induction motors were much more expensive.
Dave
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On Thu, 22 Dec 2005 12:13:57 GMT, "david lang"

Induction is cheaper for a specific power, or for almost all large motors. Brushed is cheaper for small low powered motors that still need high torque. If you can go to a direct-drive design, then using a brushed motor and no gearbox is usually cheaper, but you need a motor that can provide the required torque on its own shaft.
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Relatively constant speed operation under variable load, without the expense of speed-sensor and controller?
--
Tony Williams.

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Andy Dingley wrote:

Nope. Definitely an 8 micro-Farad capacitor.
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powerstation wrote:

Yep. It is.
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by the capacitor being affixed too close to the motor, the spare part now includes a bracket to move it further away. Sometimes even when the part is replaced the motor subsequently burns out if the windings have been damaged by a stalled motor.
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TB ? (Technical Brief?)
Where can I see this info?
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Peter
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Why do you say that? Most European washing machines use series wound universal motors with carbon brushes. I've got a Creda washer sitting in my basement right now awaiting arrival of a set of brushes amoung other things, no idea how it ended up on this side of the pond but it's a cool little machine.
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wrote:

But we were talking about a dryer. They seem to use induction motors (well, mine does).
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washing machine needs to spin at high speed
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Bob Eager wrote:

Yeah somehow I missed that we were discussing a dryer. The matching Creda dryer does in fact have an induction motor in it, weird to see a clothes dryer that will plug into a 15A 240v receptacle, US dryers are almost universally 4KW.
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But its NOT a washing machine he's fixing ! its a tumble drier
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A European washing machine operates its motor at a large number of different speeds (and even gradually vary the speed in some cases) throughout various stages of the wash cycle, and depending on the wash program selected. This is most easily done with a universal motor combined with an electronic speed control board and servo feedback. (It used to be done with an induction motor and solenoid operated gearbox 40 years ago, but that's more expensive and a lot less flexible.)
Tumble driers only have to be able to reverse the drum, but don't need to change the speed. For this simpler requirement, an induction motor tends to win.
--
Andrew Gabriel

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Why do they have to be able to reverse the drum? I've never seen a dryer that did that, obviously they must exist but I'm not sure of the benefits.
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wrote:

Loads of them do it[1]...helps to untangle the clothes.
[1] except in the backwards USA?
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