S

Shrader

Audioholic
How big of a battery back up do i need to have for my HT? I have a Panny PT AR100U PJ, yamaha rx v571 receiver, direct tv receiver, and a PS3.
 
BoredSysAdmin

BoredSysAdmin

Audioholic Slumlord
How big of a battery back up do i need to have for my HT? I have a Panny PT AR100U PJ, yamaha rx v571 receiver, direct tv receiver, and a PS3.
How long do you expect to run of battery? 30 seconds or 30 hours ;):rolleyes:
 
T

Tin Ear

Junior Audioholic
I would think for power outages and data retention that either of the 2 Tripp Lite units offered at accessories4less would be just fine ... only 99 bones for either and both are solid units. I run the smaller of the 2 and it seems to be just fine.
 
S

Shrader

Audioholic
Just enough time to cool the bulb in the PJ I would think, The power goes out fairly often where i am, just want to protect the equipment is all.
 
BoredSysAdmin

BoredSysAdmin

Audioholic Slumlord
I would think for power outages and data retention that either of the 2 Tripp Lite units offered at accessories4less would be just fine ... only 99 bones for either and both are solid units. I run the smaller of the 2 and it seems to be just fine.
the "bigger" one would is ranked at 1000VA/500W and 3 minutes under full load
- OP's PJ alone is 350W (max) and PS3 (depends on model) Max load is as high as 205W, Yammi 270W

Add other stuff and I expect it to last (while used) for much less than 3 minutes...

Goes to my previous question - How long does OP expect the battery to last ??

Edit:
With PJ alone protected the 1000VA unit could last 5-8 minutes
 
S

Shrader

Audioholic
Is 5-8 min. enough to protect the bulb in the PJ? I have no clue as to how long it takes a pj to "shut down" It is not like I would expect to watch an entire movie when the power goes out, as I stated just want to protect the PJ.
 
BoredSysAdmin

BoredSysAdmin

Audioholic Slumlord
Is 5-8 min. enough to protect the bulb in the PJ? I have no clue as to how long it takes a pj to "shut down" It is not like I would expect to watch an entire movie when the power goes out, as I stated just want to protect the PJ.
I'm not experts on PJs but most them take time to warm up, not to shutdown... I used both LCD and DLP PJs and both shutdown within under 10 seconds...
Maybe BMX could offer deeper knowledge as he's out in house expert
 
mtrycrafts

mtrycrafts

Seriously, I have no life.
Is 5-8 min. enough to protect the bulb in the PJ? I have no clue as to how long it takes a pj to "shut down" It is not like I would expect to watch an entire movie when the power goes out, as I stated just want to protect the PJ.
While I have not timed the actual shut off of the fan after the pj is turned off, it does run several minutes for sure.
Next time you watch a movie, time it, unless your question is in preparation to buying a pj.
 
jonnythan

jonnythan

Audioholic Ninja
Can someone explain to me why this is necessary? The bulb won't get hotter after it's turned off.
 
F

FirstReflection

AV Rant Co-Host
Can someone explain to me why this is necessary? The bulb won't get hotter after it's turned off.
Battery backup UPS is vital, IMO.

With a front projector, or any display that uses a high output lamp, the lamp gets VERY hot during operation. When you shut down the display, the cooling fan continues to run for several minutes in order to allow the lamp to properly cool down. If you get a black out, that cooling fan shuts off instantly, and the lamp can quickly overheat. This almost always shortens the life of your lamp. In some extreme cases, the lamp can crack or even explode. Having a battery backup so that you can properly shut down the PJ in the event of a black out or power outage is critical for this purpose.

I also think a battery backup UPS is absolutely vital for your DVR, and to a somewhat lesser extent, your videogame systems and anything with a hard drive. I don't know about you, but I hate losing any recordings in progress or losing my save in a videogame. Again, a batter backup UPS keeps power flowing to your devices in the event of a power outage.

Now, with a display or a videogame system, you don't necessarily need a lot of battery life. You just need enough time to shut down the display and let the cooling fan continue to run for a few minutes (which takes very little power since the display isn't actually powered up, it's just running the cooling fan), and for videogames, you just need enough time to save your game and shut down.

For a DVR though, it's awfully nice to have around 2 hours of battery life on tap. Naturally, you'll get the longest run time if you completely shut down (or unplug) all other devices from the battery backup UPS unit. Most DVRs draw about 60 Watts while they're running. With a decent-sized battery, you can keep that sucker up and running for a good 1.5 - 2 hours, which will hopefully be enough time to either complete your recording in progress, or for the power company to get the power back on!

I'm a huge, huge fan of APC AV . I trust them the most for my power protection needs.

Their J-Type Units are a great value. I use the J15BLK myself, which I adore since it has never failed to keep my DVR recording, and it also provides superb power protection from all other types of faults in my building's power.

The J15BLK is a bit expensive and overkill for most folks though. The J25B is the best value in APC's lineup. It has fewer outlets (8 total, rather than the 12 in the J15BLK), and only 6 of the J25B's outlets have the battery protection (all 12 outlets in the J15BLK are connected to the battery). But the battery life in the J25B is just as good as the J15BLK, so it's a tremendous value, and perfect for protecting your DVR and keeping your recordings in progress going!

Monoprice.com also has an inexpensive battery backup unit . I haven't used it myself though, so I can't vouch for it. 4 battery backup outlets and 6 other outlets on that unit. And what seems to be about 2/3rds of the battery life of the APC J-Type units. Should still be good for keeping your DVR running for about an hour, so long as you completely turn off everthing else ;)

You can find the APC J25B for about $200 online though. At that price, I see no reason to go with any other brand or unit. Can't recommend it highly enough :)
 
S

Shrader

Audioholic
Thank you very much, That was the answer I was looking for.
 
jonnythan

jonnythan

Audioholic Ninja
If you get a black out, that cooling fan shuts off instantly, and the lamp can quickly overheat.
I've heard this claim before, and that's where my problem is. There's no way that's true. The lamp is the unit producing heat. Once power it cuts, it stops producing heat. There is no way it can actually increase in temperature after power is cut, cooling fan or no.
 
F

FirstReflection

AV Rant Co-Host
I've heard this claim before, and that's where my problem is. There's no way that's true. The lamp is the unit producing heat. Once power it cuts, it stops producing heat. There is no way it can actually increase in temperature after power is cut, cooling fan or no.
Actually, you're right that my use of the word "overheat" is incorrect. It's just easier for most people to quickly understand. But you're right, overheating isn't actually the problem. Rapid cooling is!

Ever seen what happens when a super hot piece of metal suddenly cools down really quickly? It can crack, it can shatter, or it can explode! That's actually the danger in losing power to a UHP or Xenon projector lamp. Just as it takes a while to gradually heat up the projector's lamp when you first turn it on, so too must you gradually cool down the lamp when you turn it off. Too rapid a heating or cooling of the metal elements of the lamp can lead to too rapid expansion or contraction due to that change in temperature. So it's all about a gradual warm up, and a gradual cool down.

The fan in a projector doesn't really do that much. It's just expelling the hot air created by the hot lamp so that other components in the projector won't overheat. But cutting power to the fan isn't likely to cause problems. The problem is in cutting power to the lamp so that it instantly goes from being extremely hot, to having no power being applied at all, and thus cooling down far too rapidly!

It's just easier for folks to hear and understand about the fan and the idea of overheating. But you're right. That's really not the danger, so I apologize for using that inaccurate shortcut in my explanation. The reason the fan keeps running for a while is because the lamp is gradually being cooled down, and is thus, still producing heat that needs to be expelled from the projector's case. But losing power to the fan isn't the problem. It's not being able to gradually lower the temperature of the lamp, just like you have to gradually heat it up when you turn it on. ;)

Does that make more sense?

EDIT:

Actually, to be more accurate, you've got the super hot metal elements of the lamp, but also the super hot, pressurized gas inside the lamp as well. The pressurized gas cools more rapidly than the metal housing if the power cuts out suddenly, which leads to a sudden drop in pressure, and that can cause an implosion of the lamp, although pieces of the metal and glass frame will often scatter as a result.

Regardless, the danger in losing power suddenly is the too rapid cooling of the lamp. The temperature needs to be brought down gradually so that the contraction of the metal, glass and gas does not happen too rapidly ;)
 
Last edited:
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greatdavide

Audioholic Intern
Cooling process of high temp bulbs.

Where I work we do projectors of a sort...Heads up displays.
When we use high temp bulbs the fan stays on not to protect the bulb which is built to handle the heat but to protect the circuitry nearby. The bulb retains a substantial amount of heat for quite awhile after switching off. The metal, gas and glass of the bulb radiate heat for several minutes necessitating the cooling of the circuitry near the bulb.

Also there are extremely high temp bulbs rarely used outside of industrial situations that require that the power to them be dropped slowly so that even if they are not emitting visible light the stepped down power is providing enough energy to allow the bulb to cool slowly. These are very high temp bulbs that provide unique wavelengths and usually are not used in retail products.
 
BoredSysAdmin

BoredSysAdmin

Audioholic Slumlord
Where I work we do projectors of a sort...Heads up displays.
When we use high temp bulbs the fan stays on not to protect the bulb which is built to handle the heat but to protect the circuitry nearby. The bulb retains a substantial amount of heat for quite awhile after switching off. The metal, gas and glass of the bulb radiate heat for several minutes necessitating the cooling of the circuitry near the bulb.
This makes a lot sense, thx!!
 
jonnythan

jonnythan

Audioholic Ninja
Just as it takes a while to gradually heat up the projector's lamp when you first turn it on, so too must you gradually cool down the lamp when you turn it off.
So you're saying that there's some circuit in the projector that not just runs the fan after it's off, but pumps some juice through the bulb to keep it from cooling too quickly?

Forgive me, but that's simple BS. You're just making stuff up as you go along.
 

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