Went to use George to clean a carpet this morning. The pump didn't work.

Checked continuity and found that the lead from the switch to the pump
appears to be open circuit on the 'live' (brown) side.

This lead is two separate stranded wires with Lucar style connectors and
an outer loose fabric sleeving. No sign of damage.

Pulling back the outer reveals that the brown wire is sleeved in black
for part of its length and has little hard cylinders in it. Suppressors?

I don't want to just replace the wire without knowing what I'm leaving
out.

Anyone?

On Sun, 23 Aug 2015 10:51:23 +0000, Bob Eager wrote:

Went to use George to clean a carpet this morning. The pump didn't work.

Checked continuity and found that the lead from the switch to the pump
appears to be open circuit on the 'live' (brown) side.

This lead is two separate stranded wires with Lucar style connectors and
an outer loose fabric sleeving. No sign of damage.

Pulling back the outer reveals that the brown wire is sleeved in black
for part of its length and has little hard cylinders in it. Suppressors?

I don't want to just replace the wire without knowing what I'm leaving
out.

Anyone?

Aha. Seems it's a diode. Anyone have any more info?

Bob Eager wrote:

Pulling back the outer reveals that the brown wire is sleeved in black
for part of its length and has little hard cylinders in it. ne?

Aha. Seems it's a diode. Anyone have any more info?

Probably cheaper than finding a suitable replacement from Maplin, if you
can wait a day or two ...

http://discountedcleaningsupplies.co.uk/diode-assembly-numatic-320830

On Sun, 23 Aug 2015 12:12:38 +0100, Andy Burns wrote:

Bob Eager wrote:

Pulling back the outer reveals that the brown wire is sleeved in black
for part of its length and has little hard cylinders in it. ne?

Aha. Seems it's a diode. Anyone have any more info?

Probably cheaper than finding a suitable replacement from Maplin, if you
can wait a day or two ...

http://discountedcleaningsupplies.co.uk/diode-assembly-numatic-320830

Yes, that's how I found out. I have ordered one from somewhere.

Meanwhile, it's a 1N4007. Which isn't a 'thermal' diode in that sense, so
not quite sure how this works.

I probably have one somewhere. Off to check.

Bob Eager wrote:
On Sun, 23 Aug 2015 12:12:38 +0100, Andy Burns wrote:

Bob Eager wrote:

Pulling back the outer reveals that the brown wire is sleeved in black
for part of its length and has little hard cylinders in it. ne?

Aha. Seems it's a diode. Anyone have any more info?

Probably cheaper than finding a suitable replacement from Maplin, if you
can wait a day or two ...

http://discountedcleaningsupplies.co.uk/diode-assembly-numatic-320830

Yes, that's how I found out. I have ordered one from somewhere.

Meanwhile, it's a 1N4007. Which isn't a 'thermal' diode in that sense, so
not quite sure how this works.

I probably have one somewhere. Off to check.

What do you mean by a thermal diode? The forward voltage of any diode
has a temperature coefficient -0.002V per degree C for silicon)but that
is the only thermal connection to a diode I can think of.

I presume the pump in question is run from half wave AC to control the
speed or power dissipation for some reason.

Some cheap electric drills have a switchable diode to provide two
speeds/power levels rather than doing it properly with a gearbox.

On 23/08/2015 12:59, Bob Minchin wrote:
Bob Eager wrote:
On Sun, 23 Aug 2015 12:12:38 +0100, Andy Burns wrote:

Bob Eager wrote:

Pulling back the outer reveals that the brown wire is sleeved in black
for part of its length and has little hard cylinders in it. ne?

Aha. Seems it's a diode. Anyone have any more info?

Probably cheaper than finding a suitable replacement from Maplin, if you
can wait a day or two ...

http://discountedcleaningsupplies.co.uk/diode-assembly-numatic-320830

Yes, that's how I found out. I have ordered one from somewhere.

Meanwhile, it's a 1N4007. Which isn't a 'thermal' diode in that sense, so
not quite sure how this works.

I probably have one somewhere. Off to check.

What do you mean by a thermal diode? The forward voltage of any diode
has a temperature coefficient -0.002V per degree C for silicon)but that
is the only thermal connection to a diode I can think of.

I presume the pump in question is run from half wave AC to control the
speed or power dissipation for some reason.

Some cheap electric drills have a switchable diode to provide two
speeds/power levels rather than doing it properly with a gearbox.

The Gotek pump in those works on the same principle as an electric door
bell. Would that be anything to do with it?

On 23 Aug 2015 11:35:03 GMT, Bob Eager wrote:

On Sun, 23 Aug 2015 12:12:38 +0100, Andy Burns wrote:

Bob Eager wrote:

Pulling back the outer reveals that the brown wire is sleeved in black
for part of its length and has little hard cylinders in it. ne?

Aha. Seems it's a diode. Anyone have any more info?

Probably cheaper than finding a suitable replacement from Maplin, if you
can wait a day or two ...

http://discountedcleaningsupplies.co.uk/diode-assembly-numatic-320830

Yes, that's how I found out. I have ordered one from somewhere.

Meanwhile, it's a 1N4007. Which isn't a 'thermal' diode in that sense, so
not quite sure how this works.

I probably have one somewhere. Off to check.

Are you sure it's a diode?
If it's the size of a typical diode and bullet shaped with a full
metal jacket (as it were) then it's a thermal fuse.
https://en.wikipedia.org/wiki/Thermal_cutoff

--

Graham.

%Profound_observation%

On Sun, 23 Aug 2015 12:59:08 +0100, Bob Minchin wrote:

Bob Eager wrote:
On Sun, 23 Aug 2015 12:12:38 +0100, Andy Burns wrote:

Bob Eager wrote:

Pulling back the outer reveals that the brown wire is sleeved in
black for part of its length and has little hard cylinders in it.
ne?

Aha. Seems it's a diode. Anyone have any more info?

Probably cheaper than finding a suitable replacement from Maplin, if
you can wait a day or two ...

http://discountedcleaningsupplies.co.uk/diode-assembly-
numatic-320830

Yes, that's how I found out. I have ordered one from somewhere.

Meanwhile, it's a 1N4007. Which isn't a 'thermal' diode in that sense,
so not quite sure how this works.

I probably have one somewhere. Off to check.

What do you mean by a thermal diode? The forward voltage of any diode
has a temperature coefficient -0.002V per degree C for silicon)but that
is the only thermal connection to a diode I can think of.

I presume the pump in question is run from half wave AC to control the
speed or power dissipation for some reason.

I'm just repeating what the spares list says on one website! Which I
think is wrong. It's just a diode, probably for the reasons you give.

On Sun, 23 Aug 2015 13:07:54 +0100, Graham. wrote:

On 23 Aug 2015 11:35:03 GMT, Bob Eager wrote:

On Sun, 23 Aug 2015 12:12:38 +0100, Andy Burns wrote:

Bob Eager wrote:

Pulling back the outer reveals that the brown wire is sleeved in
black for part of its length and has little hard cylinders in it.
ne?

Aha. Seems it's a diode. Anyone have any more info?

Probably cheaper than finding a suitable replacement from Maplin, if
you can wait a day or two ...

http://discountedcleaningsupplies.co.uk/diode-assembly-
numatic-320830

Yes, that's how I found out. I have ordered one from somewhere.

Meanwhile, it's a 1N4007. Which isn't a 'thermal' diode in that sense,
so not quite sure how this works.

I probably have one somewhere. Off to check.

Are you sure it's a diode?
If it's the size of a typical diode and bullet shaped with a full metal
jacket (as it were) then it's a thermal fuse.
https://en.wikipedia.org/wiki/Thermal_cutoff

Since it has a plastic casing and has '1N4007' written on it...

On Sun, 23 Aug 2015 13:01:53 +0100, David Lang wrote:

On 23/08/2015 12:59, Bob Minchin wrote:
Bob Eager wrote:
On Sun, 23 Aug 2015 12:12:38 +0100, Andy Burns wrote:

Bob Eager wrote:

Pulling back the outer reveals that the brown wire is sleeved in
black for part of its length and has little hard cylinders in it.
ne?

Aha. Seems it's a diode. Anyone have any more info?

Probably cheaper than finding a suitable replacement from Maplin, if
you can wait a day or two ...

http://discountedcleaningsupplies.co.uk/diode-assembly-
numatic-320830

Yes, that's how I found out. I have ordered one from somewhere.

Meanwhile, it's a 1N4007. Which isn't a 'thermal' diode in that sense,
so not quite sure how this works.

I probably have one somewhere. Off to check.

What do you mean by a thermal diode? The forward voltage of any diode
has a temperature coefficient -0.002V per degree C for silicon)but that
is the only thermal connection to a diode I can think of.

I presume the pump in question is run from half wave AC to control the
speed or power dissipation for some reason.

Some cheap electric drills have a switchable diode to provide two
speeds/power levels rather than doing it properly with a gearbox.

The Gotek pump in those works on the same principle as an electric door
bell. Would that be anything to do with it?

The pump clearly works on AC as there are no contacts. But it may be half
wave AC as described.

Anyway, I'll replace the diode and see what happens.

If the pump manufacturers recomendations are followed then one "bump"
is a fuse and the other a diode.

The fuse is easy to check and the diode normally fails short, i.e it
will read low ohms both ways round on an Ohmeter.

Numatics parts list makes interesting reading. A Numatic George built
from manufacturers spares must approach the cost of a small mansion in
Belgravia.


AB.


On 23 Aug 2015 13:02:40 GMT, Bob Eager wrote:

On Sun, 23 Aug 2015 13:07:54 +0100, Graham. wrote:

On 23 Aug 2015 11:35:03 GMT, Bob Eager wrote:

On Sun, 23 Aug 2015 12:12:38 +0100, Andy Burns wrote:

Bob Eager wrote:

Pulling back the outer reveals that the brown wire is sleeved in
black for part of its length and has little hard cylinders in it.
ne?

Aha. Seems it's a diode. Anyone have any more info?

Probably cheaper than finding a suitable replacement from Maplin, if
you can wait a day or two ...

http://discountedcleaningsupplies.co.uk/diode-assembly-
numatic-320830

Yes, that's how I found out. I have ordered one from somewhere.

Meanwhile, it's a 1N4007. Which isn't a 'thermal' diode in that sense,
so not quite sure how this works.

I probably have one somewhere. Off to check.

Are you sure it's a diode?
If it's the size of a typical diode and bullet shaped with a full metal
jacket (as it were) then it's a thermal fuse.
https://en.wikipedia.org/wiki/Thermal_cutoff

Since it has a plastic casing and has '1N4007' written on it...

Sorry, forgot the link!!

http://www.gotecpumps.com/multimedia...nical_data.pdf


AB.

On Sun, 23 Aug 2015 17:40:29 +0100, Archibald Tarquin Blenkinsopp wrote:

If the pump manufacturers recomendations are followed then one "bump" is
a fuse and the other a diode.

Turns out two of the 'bumps' are crimps and the third is the diode.

Numatics parts list makes interesting reading. A Numatic George built
from manufacturers spares must approach the cost of a small mansion in
Belgravia.

I agree!

On Sun, 23 Aug 2015 17:42:24 +0100, Archibald Tarquin Blenkinsopp wrote:

Sorry, forgot the link!!

http://www.gotecpumps.com/multimedia...09/06/ETS_21_-
_Technical_data.pdf


AB.

Thanks...interesting.

On 26/08/2015 23:17, Bob Eager wrote:
On Wed, 26 Aug 2015 22:11:25 +0000, Andrew Gabriel wrote:

In article ,
Bob Eager writes:
On Sun, 23 Aug 2015 17:40:29 +0100, Archibald Tarquin Blenkinsopp
wrote:

If the pump manufacturers recomendations are followed then one "bump"
is a fuse and the other a diode.

Turns out two of the 'bumps' are crimps and the third is the diode.

Sounds like one I've had turn up at a repair event.
IIRC, one of the crimps was a bad connection, and the diode had
overheated as a result. I think the motor was a DC (permanent magnet)
motor. I don't think a 50Hz AC motor that small can be made which is
powerful enough - not even enough space for having universal motor field
windings.

The pump is a strange device. Basically a winding surrounding a spring
loaded metal slug in a cylinder, with a non return valve and a channel
connecting the two ends of the cylinder (can't see the channel but it
must be there).

The work on the same principle as an old fashioned door bell. Made by
Gotek if that's any help.



No chance to work on it, probably until the weekend. Need to find some
crimps.

On Thu, 27 Aug 2015 19:32:36 +0100, David Lang wrote:

The pump is a strange device. Basically a winding surrounding a spring
loaded metal slug in a cylinder, with a non return valve and a channel
connecting the two ends of the cylinder (can't see the channel but it
must be there).

The work on the same principle as an old fashioned door bell. Made by
Gotek if that's any help.

Yes, someone posted a link. Except doorbells don't need diodes, and only
AC doorbells!