Home |
Search |
Today's Posts |
![]() |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
Nothing working , neither motor, 1Meg across mains "on or off". No obvious
water ingress, nasty smells, or burning. 24 segment armature, .2mm wire , 25 to 27 ohm across brushes for 1 rev. Beater motor opened up, bowl motor not seen. A thin multistrand wire with yellow sleeving , loose inside with no obvious tag remnants to the motor. The stator has yellow high temp tape around it and picking off part of the last turn there is a broken wire with a lot of copper carbonate corrossion. But this wire is .15mm which seems small for a presumed 380/2 W motor , 380W m/c total. Some sort of sense wire ? and without it the , unseen, presumed triac control inside the handle is disabled. I find it difficult to believe ..15mm wire would be actively in a mains motor stator even if it is for the slowest setting. 8 exposed magnet wire ends around this stator of .4, .2 and ..15 mm diameters if the broken one is included. Even if repaired how to avoid more water/condensation damage on such fine wire ? |
#2
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
I think I've found where the yellow wire is broken from, it is the neutral
from the mains and is twisted to a grey wire before being soldered to a tag. Desoldering it then it become obvious that what looked like the end of the grey wire is the remnant multistrands of the yellow.. I'm only in delayed contact with the owner. I suspect this wire broke on me removing the motor, the 1M over the mains seems to be the R of a mains RC filter. There is 10 wire ends to the stator, down to .1mm which marries up to the remnant on a tag. A .4 mm wire is soldered internally , under the yellow tape to a probably .15mm wire that then presumably carries on to a tag with a remnant ..15 mm wire on it. Someone's idea of a fuse ? I've looked on one side of this .4mm soldered end, under x30 and can see no sign of a break, will try turning it to view the other side. I suspect these 5 stator wires in parallel/series give the hi/low + boost and 1 to 5 speed ranges and no triac control. Elsewise joining .4 to .15mm wire makes no sense. I suspect the owner lost the .1mm low speed range some time back and then sometime the ..15mm wire broke and then the neutral connection . I would have expected to only see .1mm wire in a mains clock motor not a torquey motor. The motor at the rotor pole pieces, so about 18mm radius, requires about 100 gram to turn, Compared to drill motors this seems a bit tight. I've not removed the nylon gears yet to check but a bit of turning resistance might have led to an overload of motor current |
#3
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
Got it running on positions 2 to 5 low to full speed with right sort of
power draw off the mains , hi/lo works and boost works all up to full mains but pos 1 has problems. I used a variac of course initially and pos 1 was going in reverse at 30 percent mains, at full tilt as though on 5. At 50 percent mains for half a second, no motion, nasty buzz and mains draw of over 1 amp. Where to go from here , I assume pos 1 is not reverse or it would be marked R, what have I miswired ? Time to delve into the handle and its switches |
#4
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
On Dec 15, 6:37*am, "N_Cook" wrote:
Got it running on positions 2 to 5 low to full speed with *right sort of power draw off the mains , hi/lo works and boost works all up to full mains but pos 1 has problems. I used a variac of course initially and pos 1 was going in reverse at 30 percent mains, at full tilt as though on 5. At 50 percent mains for half a second, no motion, nasty buzz and mains draw of over 1 amp. Where to go from here , I assume pos 1 is not reverse or it would be marked R, what have I miswired ? Time to delve into the handle and its switches Stamp an R over the 1 and call it quits. |
#5
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
wrote in message
... On Dec 15, 6:37 am, "N_Cook" wrote: Got it running on positions 2 to 5 low to full speed with right sort of power draw off the mains , hi/lo works and boost works all up to full mains but pos 1 has problems. I used a variac of course initially and pos 1 was going in reverse at 30 percent mains, at full tilt as though on 5. At 50 percent mains for half a second, no motion, nasty buzz and mains draw of over 1 amp. Where to go from here , I assume pos 1 is not reverse or it would be marked R, what have I miswired ? Time to delve into the handle and its switches Stamp an R over the 1 and call it quits. ++++ quits being a puff of smoke, disable the "1" linw when you know which it is , maybe. Getting inside the handle it all became obvious once you know which is the low current, low speed lead when they are all the same size multistrand gauge of wire going into the handle . Inside just a simple 1 to 6 pole sw and 2x 2 position slide sw, then 2 off x2 yellow blocks, 2 blue disc ceramic over the commutator and no electronics at all. |
#6
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
Looks as though this is how it failed. Not made for mixing thick mixtures at
low speed as .1mm wire for the last run of that 1 setting and over time the wire must have brittalised+corroded from excess load current and failed at one end where the loose tails can vibrate, break and blow out through the housing. Continued being used but without speed 1 and at some point the second end must have broken away and blown out, leaving just 2 tiny remnant bits at the solder points, easily overlooked, and other break ends under the bulk of windings , so unseen. Then the neutral connection failed and no use after that. Will try a diode in the 1 position linked to the 2 winding |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|