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Average modem power consumption in watts?

foxbrook
Sophomore

Re: Average modem power consumption in watts?

The power ratings on the label of a power brick are the ratings that were used when the power supply was tested by UL for safety. They may or may not have anything to do with the actual power draw of the modem. The reason for the higher input power rating, other than the efficiency loss of the circuit, is that UL requires the unit remain safe during fault conditions, such as a shorted output or a component failure within the power supply. Under these conditions the current draw can be higher, than under normal operating conditions.

Anyway, as I sit here typing this my Killawatt meter on my HT1100 modem shows it is drawing 23W at 120V input.
FIA Ranch
New Member

Re: Average modem power consumption in watts?

Excellent point foxbrook.... totally spaced UL involvement in this whole picture...
Timothy Southwa
New Member

Re: Average modem power consumption in watts?

Thank you for your help. You've given me a better understanding of things. I do still have some questions. One, do I understand you correctly? I think you're saying that the modem on the modem side of the adapter uses a fairly steady 46 watts no matter what.
There is the possibility that the modem uses power to amplify the incoming signal. But, if so, such must be little since an Iridium 9555 satellite phone uses only about 0.5 watts.
Is it possible that the modem uses much more power to compute and determine and straighten out the data contained in an incoming signal that's been seriously degraded by weather conditions, solar conditions, whatever?
In between transmitting and receiving times is the modem idle, using only a few watts at most? If so, then given the high uploading and downloading speeds of the whole system, the modem would be idle most of the time when someone is surfing the web, since he will spend much of his time looking at each website, printing it, whatever. If the modem uses little power idling, such could more or less provide a reconciliation between what you've said and what Curtis-m said.
Does HughesNet use the world's most inefficient power adapter, converting about 150 watts ac to 46 watts dc. I use only dc. Is there a way to connect the modem directly to a dc source of power?
FIA Ranch
New Member

Re: Average modem power consumption in watts?

Good morning.... let me work through your questions....

"I think you're saying that the modem on the modem side of the adapter uses a fairly steady 46 watts no matter what."

Not quite..... It is "rated" at 46 watts consumption of AC power.  That is the AC line side of the adapter.  As foxbrook pointed out (and I spaced out), the discrepancy between the numbers listed on the brick are what the brick is expected to produce to supply the modem and radio, and what it actually produces, and what its UL limits are.

Depending on the condition of the modem and radio components, the "brick" will produce the appropriate DC voltages on the modem side of the brick up to that 46 watt of AC consumption.

As curtis-m said, it appears that his is using somewhere around 9 watts of power.  And my caution with that is, as I said, there are different types of inverters (three to be exact), their quality, stability, etc. will vary, and so on.

That is why I said your decision is a personal choice.  For planning purposes, do you plan for "max" (46 watts), do you plan for "probable" (10 watts or so), or do you take a stand somewhere in the middle. (20-25 watts?)  That is just a "comfort" decision.


"Is it possible that the modem uses much more power to compute and determine and straighten out the data contained in an incoming signal that's been seriously degraded by weather conditions, solar conditions, whatever?"

In a word, no. It does use more computing power in the processor when it is dealing with exterior conditions (good or bad), but that does not translate to any significant difference in AC power usage.  Some minuscule changes?  Most likely.  But nothing in the grand scheme of things.


"In between transmitting and receiving times is the modem idle, using only a few watts at most? "

Again, no.  When the modem is powered on, the radio is powered on.  And the two devices are the sum total of AC power consumption, regardless of any user activity.  Other than the minuscule changes I mentioned above based on how hard the CPU may be working at any given point in time.

"such could more or less provide a reconciliation between what you've said and what Curtis-m said."

Think I answered that.  A simple analogy.  A car tire may be built to run 120mph (the UL rating), but will it ever?  Possibly, but not likely.

"Does HughesNet use the world's most inefficient power adapter, converting about 150 watts ac to 46 watts dc.

A couple of parts to that.

First, again, as foxbrook said, the 150 watt number is the UL maximum current draw that can be expected under the most extreme component failure.  As with most UL things, they have little relation to reality.

Second, the 46 watts is not DC, that is still on the AC side of the brick.

"I use only dc. Is there a way to connect the modem directly to a dc source of power?"

No.  the power brick produces several DC voltages from the AC source.  I have not taken a volt meter to determine what they are in this particular instance, but the common power brick usually produces anywhere from 3 to 6 various DC voltages that range from -/+5vdc to -/+48vdc. and are used for isolated purposes within the equipment.  It might even pass 120VAC through to the modem in addition to the DC.  As I said, I just haven't checked to see what it is providing.


Hope that helps.  If I missed something, or you have more questions, fire away......
Timothy Southwa
New Member

Re: Average modem power consumption in watts?

You have been quite helpful. Thank you very much. I may yet ask you more questions.
Timothy Southwa
New Member

Re: Average modem power consumption in watts?

Thank you for your explanation foxbrook. Also, I appreciate you reporting your actual power usage