In conjunction with my work I operate a computer and printer in my vehicle. The printer is powered by a 1000w inverter. Recently the printer shows errors and will not operate on the inverter (it works fine on POCO power) Inverter voltage is 112-117. I thought possibly some type of filter would help. Any suggestions?
Power Line Filter
- Thread starter augie47
- Start date
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- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Make sure that the inverter is Pure Sine Wave (PSW) instead of Modified Square Wave (MSW).
That should greatly reduce the potential for interference.
Beyond that an ordinary RF filter on each individual AC line right at the power brick should help too.
You could have induced noise on the wire from computer to printer, so keep that short and possibly run it through a ferrite core.
That should greatly reduce the potential for interference.
Beyond that an ordinary RF filter on each individual AC line right at the power brick should help too.
You could have induced noise on the wire from computer to printer, so keep that short and possibly run it through a ferrite core.
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
151204-1135 EST
augie47:
What kind of printer?
Power (peak if known)? Laser printers have a heater. In small printers this can be several hundred watts when on. Larger printers over 1000 W.
How is data communicated from computer to printer? RS232, RS422, USB, parallrel, or RF.
Does the computer have a 2 prong only AC plug, or is it 3 prong?
Can the computer be run on its own battery? If operated in this mode with the computer AC cable removed are there printer errors?
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augie47:
What kind of printer?
Power (peak if known)? Laser printers have a heater. In small printers this can be several hundred watts when on. Larger printers over 1000 W.
How is data communicated from computer to printer? RS232, RS422, USB, parallrel, or RF.
Does the computer have a 2 prong only AC plug, or is it 3 prong?
Can the computer be run on its own battery? If operated in this mode with the computer AC cable removed are there printer errors?
.
mgookin
Senior Member
- Location
- Fort Myers, FL
If you're not sure, a quick way to find out is put a AC volt meter on the output. A modified sine wave will read about 80VAC IIRC.
If you have an off the shelf inkjet printer it may require DC anyway. Maybe consider bypassing the inverter.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
That reading is only expected if the meter measures peak and converts to RMS by assuming a sine wave.
A true RMS meter should read 120 for MSW or PSW.
The Spunkster
Member
- Location
- NJ----USA
How about a scope? Always worked for me!
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Running off the inverter? :angel:
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Take a look at the output voltage.
Changes to the DC wiring or the state of the vehicle battery can affect the voltage regulation of the inverter.
At startup of the printer it will be heating the fuser section while also possibly exercising motors. And ramping up the high voltage DC supply.
Changes to the DC wiring or the state of the vehicle battery can affect the voltage regulation of the inverter.
At startup of the printer it will be heating the fuser section while also possibly exercising motors. And ramping up the high voltage DC supply.
mgookin
Senior Member
- Location
- Fort Myers, FL
Thank you. We bought a cheap inverter one day and took it out to the parking lot. The electronics plugged in made quite a racket so we disconnected power. Then we measured voltage coming out of it and I believe it was a 80-ish VAC reading. Read the instructions and it said that's what's expected. Took it back to the store before we left the parking lot. Apparently our meter measures peak and converts to RMS by assuming the sine wave as you say. Thanks for the education!
iceworm
Curmudgeon still using printed IEEE Color Books
- Location
- North of the 65 parallel
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- EE (Field - as little design as possible)
$S is right on. No concern about pure sinewave, modified, too small, or anything else. It did work, now it doesn't - something broke. As you knew, since the printer works fine on POCO power, it's likely the inverter.
So, 1000 inverter on 12V is ~80A. That is some pretty healthy wire from the batery to the inverter. I'd likely start with the connection and wire routing.
Then maybe try a direct connection to a battery separate from the car charging system.
And, of course if you can borrow one ....
Just some thoughts
You say recently. That infers that it is a new problem where there wasn't one before.
So, did the printer ever work in the vehicle?
I took someone else word on the voltage measurement.
When I measure the output with my fluke I show 98v with no load, however, with my limited knowledge of the type output I don't know if thats normal.
The website states:
"Output Waveforms: Short-Wave, Switching Power: 85% above, Circuit Mode: P.W.M"
Input voltage is 14.8 DC.
When I measure the output with my fluke I show 98v with no load, however, with my limited knowledge of the type output I don't know if thats normal.
The website states:
"Output Waveforms: Short-Wave, Switching Power: 85% above, Circuit Mode: P.W.M"
Input voltage is 14.8 DC.
Nutmegger
Senior Member
- Location
- Fairfield County, Connecticut
Regardless of the nameplate wattage rating of the printer, laser printers draw significant inrush current upon startup and in the beginning of the print engine cycle, AFAIK.
Could that be what is overwhelming the inverter?
Could that be what is overwhelming the inverter?
That's an indication of this problem waiting to happen. Why? Because that's the input voltage that the inverter is rated 1000W on. When voltage is less than that, which is common during vehicle operation, the inverter tries to put out the same wattage at lower input voltage and thus overheats. (FWIW, I've burnt up audio amps for the very same reason.)
If you replace the inverter with a brand new one, it'll likely work for awhile... then the same thing will likely happen. Try getting a 1.5 or 2kW inverter....
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
151204-2406 EST
augie47:
From your response to my questions it appears that:
1. There is only one common (ground) path from the computer to anywhere, and that is the shield or common wire in the USB cable from the computer to the printer. This basically eliminates any ground loop path.
2. That you are using a laser printer means there is substantial AC power input required at times. Small laser printers probably are instant on. Meaning fuser power is only drawn during printing, and no keep warm pulse. Small printers use less fuser power because their print speed is slower than large printers.
My HP LaserJet 5MP (a desktop moderately small printer) has a standby power load of about 50 W for the electronics. This printer I describe as having an instant on fuser. Without setting up to check it I don't know the peak fuser power at print start. During printing total power is about 300 W.
My HP 5SiMX is still a desktop, but larger (11 x 17) and faster. Its standby power is about 40 W, and a standby keep warm pulse of 1 second duration about every 10 seconds of about 520 W. Average of this pulse is about 50 W. Total average standby power is about 90 W. While printing average power is about 550 to 700 W.
3. What changed in your setup from when printing worked to now when you have printer printing problems?
4. When your engine is running a fast idle (possibly 1500 RPM) the alternator output voltage at the alternator is probably in the range of 13.5 to 14.00 V. Note engine RPM. Check this voltage when the printer is running and printing at the alternator and the input to the inverter.
When in backup mode (AC power removed) on an inexpensive non-sine wave UPS I read 110 V with a Simpson 270 (average reading calibrated in RMS, 1.1 ratio). An RV AC voltmeter reads 130 V. Both meters on a sine wave read close to a Fluke.
5. What does this statrement mean?
And in relation to your first post?
Tell me if these comments are not clear. I not sure I have said what I want to say.
.
augie47:
From your response to my questions it appears that:
1. There is only one common (ground) path from the computer to anywhere, and that is the shield or common wire in the USB cable from the computer to the printer. This basically eliminates any ground loop path.
2. That you are using a laser printer means there is substantial AC power input required at times. Small laser printers probably are instant on. Meaning fuser power is only drawn during printing, and no keep warm pulse. Small printers use less fuser power because their print speed is slower than large printers.
My HP LaserJet 5MP (a desktop moderately small printer) has a standby power load of about 50 W for the electronics. This printer I describe as having an instant on fuser. Without setting up to check it I don't know the peak fuser power at print start. During printing total power is about 300 W.
My HP 5SiMX is still a desktop, but larger (11 x 17) and faster. Its standby power is about 40 W, and a standby keep warm pulse of 1 second duration about every 10 seconds of about 520 W. Average of this pulse is about 50 W. Total average standby power is about 90 W. While printing average power is about 550 to 700 W.
3. What changed in your setup from when printing worked to now when you have printer printing problems?
4. When your engine is running a fast idle (possibly 1500 RPM) the alternator output voltage at the alternator is probably in the range of 13.5 to 14.00 V. Note engine RPM. Check this voltage when the printer is running and printing at the alternator and the input to the inverter.
When in backup mode (AC power removed) on an inexpensive non-sine wave UPS I read 110 V with a Simpson 270 (average reading calibrated in RMS, 1.1 ratio). An RV AC voltmeter reads 130 V. Both meters on a sine wave read close to a Fluke.
5. What does this statrement mean?
What is the problem that is evident on startup? And what startup (initial or print start)?
And in relation to your first post?
Doies it work at all on the inverter?
Tell me if these comments are not clear. I not sure I have said what I want to say.
.
Gary Glaenzer
Member
Power line filter
Power line filter
"Was working. Has decided it does not care for inverter power."
or is it the converse...........the inverter has decided not to provide sufficient power ?
Power line filter
"Was working. Has decided it does not care for inverter power."
or is it the converse...........the inverter has decided not to provide sufficient power ?
Since it (thr printer) works on house power I would suspect the inverter.
mgookin
Senior Member
- Location
- Fort Myers, FL
Just curious, for how long did it work? And how often is it used?
I like gar's suggestion of getting a bigger inverter.
Or maybe get a lower power printer. There are even 12VDC printers out there made specifically for those mobile offices.
I like gar's suggestion of getting a bigger inverter.
Or maybe get a lower power printer. There are even 12VDC printers out there made specifically for those mobile offices.
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