I have a troublesome paper shredder that periodically causes my cable
modem to lose its mind, and require a reboot.

Due to physical locations of outlets and cabinet spacing, I have no
choice but to use the same power strip for both shredder and modem.

I suspect conducted but I suppose it could be radiated.

Any ideas short of moving the shredder to another room ?:-)

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

Jim Thompson wrote:

I have a troublesome paper shredder that periodically causes my cable
modem to lose its mind, and require a reboot.

Due to physical locations of outlets and cabinet spacing, I have no
choice but to use the same power strip for both shredder and modem.

I suspect conducted but I suppose it could be radiated.

Any ideas short of moving the shredder to another room ?:-)


Low tech: Use a burn barrel. ;-)


--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

Jim Thompson wrote:
I have a troublesome paper shredder that periodically causes my cable
modem to lose its mind, and require a reboot.

Due to physical locations of outlets and cabinet spacing, I have no
choice but to use the same power strip for both shredder and modem.

I suspect conducted but I suppose it could be radiated.

Any ideas short of moving the shredder to another room ?:-)

...Jim Thompson
Get a 1:1 isolation xformer for the shredder..
It's most likely the universal motor being used and the
brushes arch in those.

Jamie wrote:

Jim Thompson wrote:
I have a troublesome paper shredder that periodically causes my cable
modem to lose its mind, and require a reboot.

Due to physical locations of outlets and cabinet spacing, I have no
choice but to use the same power strip for both shredder and modem.

I suspect conducted but I suppose it could be radiated.

Any ideas short of moving the shredder to another room ?:-)

Get a 1:1 isolation xformer for the shredder..
It's most likely the universal motor being used and the
brushes arch in those.



Arch? You're as stupid as dimbulb. Maybe even a notch lower.


An EMI filter pulled from a junk PC power supply and installed at the
motor would do more good, since the RFI is radiated by the wiring inside
the shreader


--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

On Sat, 9 Oct 2010 14:16:42 -0700, "BobW"
wrote:


"Jim Thompson" wrote in
message ...
I have a troublesome paper shredder that periodically causes my cable
modem to lose its mind, and require a reboot.

Due to physical locations of outlets and cabinet spacing, I have no
choice but to use the same power strip for both shredder and modem.

I suspect conducted but I suppose it could be radiated.

Any ideas short of moving the shredder to another room ?:-)

...Jim Thompson
--

Long ago, I had a computer that would drive my X10 lighting system nuts. I
had to add a line filter (some Ls and Cs, I assume) on the power plug. So,
this was a conducted emissions problem.

I suppose your shredder may be drawing so much current that the voltage to
the modem is going too low. If this is the case, you gotta either get the
shredder plugged in closer (resistance wise) to the power company or get a
more tolerant supply for the modem.

Bob

Hi Bob,

The voltage isn't dropping... otherwise the modem would reboot... it
just loses its mind :-)

Unplugging and re-plugging its wall-wart fixes it.

It's also close to a wall panel where a bunch of CAT-5 is routed :-(
I'm all hard-wired here using a LinkSys Barricade Router to other
rooms in the house.

I'll try a filter... then maybe re-think my furniture arrangement :-)

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I can see November from my house :-)

On Sat, 09 Oct 2010 11:41:31 -0700, Jim Thompson
wrote:

I have a troublesome paper shredder that periodically causes my cable
modem to lose its mind, and require a reboot.

The cable-TV coaxial cable shield is typically grounded at several
places.

If the cable modem is connected to the mains using a 3 wire cable, the
cable modem signal ground may be connected to the mains Ground/Earth
wire and finally to the house grounding electrode at the service
entry.

On the cable modem, check if there is a DC (or LF) conductivity
between the mains Earth/Ground terminal and coaxial cable socket
shield.

In such cases, a small part of the shredder high frequency noise
current may flow through the cable modem PCB into the cable operator
remote ground (due to common impedances in TN-C-S electric
distribution systems) causing havoc on the PCB. Breaking this DC and
low frequency conductivity path between the cable modem and the actual
coaxial cable (e.g. using RF isolation transformer 75:75 ohms) will
cut the DC and LF current through the cable modem.

Paul Keinanen wrote:

On Sat, 09 Oct 2010 11:41:31 -0700, Jim Thompson
wrote:

I have a troublesome paper shredder that periodically causes my cable
modem to lose its mind, and require a reboot.

The cable-TV coaxial cable shield is typically grounded at several
places.

If the cable modem is connected to the mains using a 3 wire cable, the
cable modem signal ground may be connected to the mains Ground/Earth
wire and finally to the house grounding electrode at the service
entry.

On the cable modem, check if there is a DC (or LF) conductivity
between the mains Earth/Ground terminal and coaxial cable socket
shield.

In such cases, a small part of the shredder high frequency noise
current may flow through the cable modem PCB into the cable operator
remote ground (due to common impedances in TN-C-S electric
distribution systems) causing havoc on the PCB. Breaking this DC and
low frequency conductivity path between the cable modem and the actual
coaxial cable (e.g. using RF isolation transformer 75:75 ohms) will
cut the DC and LF current through the cable modem.


I've never seen a cable modem with a three wire cord in the US. All
either used a wallwart or a two wire cord.



--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

"Jim Thompson" wrote
in message ...
I have a troublesome paper shredder that periodically causes my cable
modem to lose its mind, and require a reboot.

Due to physical locations of outlets and cabinet spacing, I have no
choice but to use the same power strip for both shredder and modem.

I suspect conducted but I suppose it could be radiated.

Any ideas short of moving the shredder to another room ?:-)

...Jim Thompson
--

Try a ISOBAR, with filtering.
http://www.tripplite.com/en/products/model.cfm?txtSeriesID=825&txtModelID=104

We filtered out some hash for a timeclock at the last place I worked.

Cheers

On Sun, 10 Oct 2010 05:40:55 -0400, "Michael A. Terrell"
wrote:


Paul Keinanen wrote:

On Sat, 09 Oct 2010 11:41:31 -0700, Jim Thompson
wrote:

I have a troublesome paper shredder that periodically causes my cable
modem to lose its mind, and require a reboot.

The cable-TV coaxial cable shield is typically grounded at several
places.

If the cable modem is connected to the mains using a 3 wire cable, the
cable modem signal ground may be connected to the mains Ground/Earth
wire and finally to the house grounding electrode at the service
entry.

On the cable modem, check if there is a DC (or LF) conductivity
between the mains Earth/Ground terminal and coaxial cable socket
shield.

In such cases, a small part of the shredder high frequency noise
current may flow through the cable modem PCB into the cable operator
remote ground (due to common impedances in TN-C-S electric
distribution systems) causing havoc on the PCB. Breaking this DC and
low frequency conductivity path between the cable modem and the actual
coaxial cable (e.g. using RF isolation transformer 75:75 ohms) will
cut the DC and LF current through the cable modem.


I've never seen a cable modem with a three wire cord in the US. All
either used a wallwart or a two wire cord.

WallWart here.

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I can see November from my house :-)

"Jim Thompson" wrote in
message ...
I have a troublesome paper shredder that periodically causes my cable
modem to lose its mind, and require a reboot.

Due to physical locations of outlets and cabinet spacing, I have no
choice but to use the same power strip for both shredder and modem.

I suspect conducted but I suppose it could be radiated.

Any ideas short of moving the shredder to another room ?:-)

I'd bet that it's conducted EMI. In such cases I've specified a Triplite
Isobar premium power strip. Extensive EMI isolation and filtering between
adjacent outlets.
http://www.tripplite.com/en/products...txtModelID=112
A bit pricey but they do solve a lot of problems.

If you feel that it's a radiated problem. just try to route the cable more
than a couple of feet away from the shredder's power cord. Sometimes you get
lucky with a clip-on ferrite.
Oppie

Jim Thompson wrote:

On Sun, 10 Oct 2010 05:40:55 -0400, "Michael A. Terrell"
wrote:


Paul Keinanen wrote:

On Sat, 09 Oct 2010 11:41:31 -0700, Jim Thompson
wrote:

I have a troublesome paper shredder that periodically causes my cable
modem to lose its mind, and require a reboot.

The cable-TV coaxial cable shield is typically grounded at several
places.

If the cable modem is connected to the mains using a 3 wire cable, the
cable modem signal ground may be connected to the mains Ground/Earth
wire and finally to the house grounding electrode at the service
entry.

On the cable modem, check if there is a DC (or LF) conductivity
between the mains Earth/Ground terminal and coaxial cable socket
shield.

In such cases, a small part of the shredder high frequency noise
current may flow through the cable modem PCB into the cable operator
remote ground (due to common impedances in TN-C-S electric
distribution systems) causing havoc on the PCB. Breaking this DC and
low frequency conductivity path between the cable modem and the actual
coaxial cable (e.g. using RF isolation transformer 75:75 ohms) will
cut the DC and LF current through the cable modem.


I've never seen a cable modem with a three wire cord in the US. All
either used a wallwart or a two wire cord.

WallWart here.


Like my Scientific Atlanta, and the Tosiba I used to have. The RCA's
are all oddball two wire AC cords.


--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

I have a troublesome paper shredder that periodically causes my cable
modem to lose its mind, and require a reboot.

Due to physical locations of outlets and cabinet spacing, I have no
choice but to use the same power strip for both shredder and modem.

I suspect conducted but I suppose it could be radiated.

I'd suggest building yourself a filter-box. Use one of the nice
metal-case CLC common-and-differential-mode powerline filter
modules... I usually think of Corcom when I think of these, but
they're made by quite a few companies.

Build it into a large outlet box, along with a fuse (or breaker) and a
line cord. Plug the filter-box into the power strip and plug the
shredder into the filter.

Alternatively, build one right into the shredder - mount it inside the
chassis right where the power cord enters the cabinet, and wire it
into the circuit at this point.

These things can be quite good at snubbing out conducted interference
from noisy motors, etc.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

"Paul Hovnanian P.E." wrote:

"Michael A. Terrell" wrote:

Jamie wrote:

Jim Thompson wrote:
I have a troublesome paper shredder that periodically causes my cable
modem to lose its mind, and require a reboot.

Due to physical locations of outlets and cabinet spacing, I have no
choice but to use the same power strip for both shredder and modem.

I suspect conducted but I suppose it could be radiated.

Any ideas short of moving the shredder to another room ?:-)

Get a 1:1 isolation xformer for the shredder..
It's most likely the universal motor being used and the
brushes arch in those.

Arch? You're as stupid as dimbulb. Maybe even a notch lower.

An EMI filter pulled from a junk PC power supply and installed at the
motor would do more good, since the RFI is radiated by the wiring inside
the shreader

Yep. Some devices utilize bypass caps mounted directly on the motor
terminals to ground.

Its possible that Jim's shredder might have had caps at one time, but
some event lead to them losing their magic smoke.


Or vibrated enough to fall off the pc board from either cracked
solder joints or metal fatigue.

He could have a motor that's about to fail, as well. I've scrapped
some shreaders and the motors were barely up to the job. The cutters
were still razor sharp, but the cheap gears were broken and the motors
needed new brushes.


--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.