What purpose does standby serve?

[Gary J. Tait]

As for time - computer maintains time of day in a circuit
completely unrelated to standby power. That design dates back
to the first IBM AT that had no standby option. Again, first
learn circuits before posting how they work.

But they did run on battery, which would need replaced (yes so do
modern PCs, but the battery is so supplement the standby supply,
should mains power fail, plus power more efficient memory technology
than the ATs had).

Plus they couldn't put themselves into standby mode like modern ATX
systems.

 

[Gary J. Tait]

Hello,

I have become embroiled in a discussion with government
representatives from many agencies about whether or not items such as
TVs, VCRs, DVDs etc should be turned off to conserve electricity as
opposed to leaving them turned on in standby mode.

Can someone PLEASE tell me why standby mode is used?

Why should such appliances be left in standby mode instead of turned
off?

If the appliance is turned off instead of being put into standby mode,
will the appliance's life be shortened, by how much and why?

I have seen sums on the energy savings if appliances are turned off
instead of being placed in standby, but I suspect that there is more
than this than meets the eye.

Many, many thanks,
Greg
Brisbane
Australia

It depends on what they are.
Sometimes, such as with satellite receivers, standby just turns off
outputs and the display, as it often has to keep the LNB powered, and
receive guide and authorisation updates (and system firmware updates,
which often need the receiver in standby to take). If you were to
often remove power from a satellite receiver, it would lose the guide
data (as that is kept in DRAM), and would miss authorisation updates,
meaning you'd lose programming.

Some DVD players "standby" is no different. (and have hard mains
switches, which I use if they are not used for extended lengths of
time).

Microwave ovens could be made to go "dark" and opening the door
activating the PS for the micro (I had one that did that, and it
wouldn't take a heck of a lot to re-work a modern oven to do the
same).

VCRS I think turn off the motors and the tuner/analog processing.

Otherwise most of the standby systems in electronics are for user
convenience.

 

[James Sweet]

In a system that consumes tens or hundreds of watts, then
1/2 watt for standby mode is the exact same thing as zero
power to those components. Standby does not extend equipment
life expectancy. Components suffer a 100% power increase
whether from standby mode or from cold restart.

It is nonsense to think that trivial current of standby mode
will save a component. Moreso, please tell us what the
current is through which parts so that parts last longer.
What are the numbers? And good luck trying.

As for time - computer maintains time of day in a circuit
completely unrelated to standby power. That design dates back
to the first IBM AT that had no standby option. Again, first
learn circuits before posting how they work.

Powering up from standby mode is no 'easier' on hardware
than powering from cold restart. The power up is different,
but just as 'stressful'. Stressful in quotes because the
stress from power up is mostly mythical - often promoted by
those who did not first learn how components work.

It's no easier on components but it does allow software control of power,
that's the whole reason for standby, to allow remote controls and software
to control powering up and shutting down the device in question. Some items
(Xbox for example) *do* use standby to maintain the system clock over long
periods, as do VCR's and some other appliances but the main purpose remains
software or logic control of device power.

 

[Greg]

All,

Thank you all very much for your comments on this issue. There are
government employees all over the world pondering this issue and the
combined resources of people like you really does help little fish
like me.

This project that I am involved with will accelerate as the
relationship between energy user and electricity supplier will
continue to challenge customer perceptions of appliance ability in
response to denials of damage libility from energy suppliers.
Legislation just gets in the way, sometimes.

Anyway, any more comments on this subject are cretainly welcome.

Cheers,
Greg

 

[[email protected]]

This is a very long shot I know, but there may be something else to be
said for leaving appliances in standby other than mere convenience.

With regard to TVs (especially cheaper ones but I have seen this in a
few ITT and Grundigs too!) where the mains switch is soldered directly
to the mainboard, constant use of this switch, and the resulting
movement, sometimes makes it work itself loose or the soldering to
crack, and the set to become intermittent, leading to other problems.

I have seen this many times on sets whose owners insist on powering
down with the hard on-off instead of standby.
Still, I doubt this is a major issue in the general scheme of
things.....

regards, Ben

 

[Jack Zeal]

This is a very long shot I know, but there may be something else to be
said for leaving appliances in standby other than mere convenience.

With regard to TVs (especially cheaper ones but I have seen this in a
few ITT and Grundigs too!) where the mains switch is soldered directly
to the mainboard, constant use of this switch, and the resulting
movement, sometimes makes it work itself loose or the soldering to
crack, and the set to become intermittent, leading to other problems.

I have seen this many times on sets whose owners insist on powering
down with the hard on-off instead of standby.
Still, I doubt this is a major issue in the general scheme of
things.....

regards, Ben

One more possibility. I know the standards for some devices to get a
energy-efficient seal from some governments are iffy at best. I think
on a lot of comp parts (monitors, printers, machines), having a standby
mode which makes it eat less than xxx watts is ample, even if it's not
very efficient when it's really on.

 

[Greg]

Hello,

Therefore, it appears to me that when a person alleges that their
VCR's or TV's power supply got "burnt out" due to a voltage surge, it
would have made no difference if the appliance was already in standby
mode?

In other words, if an appliance is in standby mode and there is an
under or overcurrent, the appliance's power supply will stand a chance
of a "burn out"?

(I sure wish I was an electrical engineer!)
Greg

 

[Sam Goldwasser]

Hello,

Therefore, it appears to me that when a person alleges that their
VCR's or TV's power supply got "burnt out" due to a voltage surge, it
would have made no difference if the appliance was already in standby
mode?

In other words, if an appliance is in standby mode and there is an
under or overcurrent, the appliance's power supply will stand a chance
of a "burn out"?

(I sure wish I was an electrical engineer!)
Greg

Hard to say. Standby power supplies can be burnt out by a surge but
may be more tolerant than the high power circuits used during normal
operation.

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[James Sweet]

Hard to say. Standby power supplies can be burnt out by a surge but
may be more tolerant than the high power circuits used during normal
operation.

And probably 90% of the time when people assume something was burned out by
a surge it actually had nothing to do with surges.