AVS Forum banner
Status
Not open for further replies.
1 - 16 of 16 Posts

·
Registered
Joined
·
2,606 Posts
Discussion Starter · #1 ·
I hate doing this off-topic of a post, but many of you can most likely answer this in 5 minutes or less, so here goes:


I'm looking for some type of relay that is controlled by the incoming AC voltage. If the AC voltage goes over/under some reasonable thresholds (say in the 95V and 140V area) the relay opens, disconnecting all attached equipment.


I realize that many companies make such devices, e.g. Panamax being one of them. But I don't want my equipment reconnected without manual intervention.


Issue is this: recently we've had some brownouts that dropped service voltage exceedingly low, only to spike up to normal, then drop back down again, etc. I'm not looking for lighting insurance, equipment protection insurance policy thingy or any of that junk, just some simple means to pull my A/V equipment off main power until I'm comfortable putting it back on.


Reason I want it automatic is I'm not always home to pull it off, and sometimes it takes me a few seconds to get my a** out of a chair (when I am home) and get to a kill switch - and this is enough time for the local edison to really do some fun things with voltage - and lately the seem to take the chance to do so.


I'm really only worried about putting this on my 5 channel amp, as it seems to not have buffering to prevent turn-on thumps and turn-off discharge through the speakers. I'm figuring the less the amp gets turned on/off, the better, so in short I'm just looking for a pretty simple/cheap solution. (Solution must be able to carry at least 15A as my amp is connected to a dedicated 20A circuit.) Would be nice to install 3 such devices to cover all gear, but the rest is generally more able to fend for itself.


If you are a dealer and resell said devices, please PM me and we'll try to set something up, I'd be more than happy to buy from you.


If its something I can build from ratshack/home depot parts, please point me in the right direction, as I'm not an electrical engineer and don't try to play one on the Internet. :)


Thanks, and sorry for such an off topic posting...
 

·
Registered
Joined
·
752 Posts
I too would be interested in this solution if it was economical!
 

·
Registered
Joined
·
2,606 Posts
Discussion Starter · #3 ·
After posting I thought about an X-10 3-way 15A appliance module. These tend to turn off when the power goes out, and they don't automatically turn back on when the power comes back on.


Problem is, they don't cut off during a brownout / undervolt situation, just blackout, and I'm driving an audio amp here, which is not something I'm keen about introducing the X-10 module's line noise to.
 

·
Registered
Joined
·
2,606 Posts
Discussion Starter · #4 ·
Here's another thought I had, my amp has a 12V trigger input, so I could take a leftover 12V wallwort, plug it into an X10 appliance module on my PC circuit (different from the amp circuit), and connect the 12V output from the wallwart to the amp's trigger input.


Now when the power blacks out entirely the 12V will drop and the amp will shutdown. When the power comes back on the X10 won't turn back on, leaving the wallwart off, and thus the amp off.


Still doesn't handle a severe undervoltage, but I already have these parts on hand.


Anyone have a better idea here? Maybe this coupled with a panamax that uses trigger inputs? The panamax unit cuts off itself during an undervoltage, and the X10/trigger arrangement I just described keeps the panamax from turning back on when power is restored?
 

·
Registered
Joined
·
90 Posts
Take a mains powered relay, and wire it so that the relay provides the power for the coil, if the power is turned off, the relay de-energises, and stays like that until turned back on...

To Turn On - you wire a push button across the contacts, so that you press it to apply power to the relay....


you then have this fed off a device which cuts the power when over or under...


the output of this relay can power a more powerful relay for all your AV gear ...
 

·
Registered
Joined
·
2,606 Posts
Discussion Starter · #7 ·
Two problems with a UPS: First, a UPS won't produce a proper sine wave, I'd have to get a very high priced unit (>$1000) to get a sine wave output even close to what the local edison creates (on its good days). The point is to try and do it for under a few hundred dollars, and to just remove my equipment from the power grid in my house when this occurs.


Fido_UK has an excellent solution, and basically what I am looking for. The Panamax/X-10 solution I offered is just about the same, as Panamax has a unit for about $200 that will disconnect the equipment when voltage goes too far out of norm, and can be controlled by a 12V trigger input. I think I can get what I want with a solution based on that.


Thanks for letting the thread be here, I think Fido's solution is the best one available today - without spending a lot of money on a PowerPlant or something.
 

·
Registered
Joined
·
264 Posts
it is very common to find very very good Online UPS with very good out put with bad battery's That you can have for free and for little to no cash.

Just look around also with all the dot.pop companies there is a lot of stuff on the streets


Most on-line UPS run without the batters and will regulate every thing


they are great for people who have to run on generators too just to get clean power out



The APC's only run if the voltage is over or under and they are cheap.


most of the newer UPS have very clean outputs. But look at the higher priced units I just got 5 3000 watt bestdata on-line UPS for free

one year of use then they were pulled.

they are big and heavy heaver then a eh8000 but a good price ;)
 

·
Registered
Joined
·
264 Posts
I also forgot there is also regulation transformer you can get.

Their are 2 types one is a saturation type and the other has a bunch of relays that adjust the taps on the transformer to keep the voltage the same.

We have tested the second type with servers (Sun E4500) and they work great. You will hear the clicking every time the voltage changes.

but never had a server crash.

Cost around $100 at the local Frys.
 

·
Registered
Joined
·
2,606 Posts
Discussion Starter · #10 ·
Hmm. Something more to think about. Thanks sly.


How's that E4500? I used to manage one and we had far too many CPU failures to justify its price. :(

It also had a very pricey APC UPS. :( :(
 

·
Registered
Joined
·
264 Posts
Quote:
Originally posted by spearce
Hmm. Something more to think about. Thanks sly.


How's that E4500? I used to manage one and we had far too many CPU failures to justify its price. :(

It also had a very pricey APC UPS. :( :(
No problem for me. My desk top is one I am using now

I have had 1 crash in 3 years due to too much dirt in the system (it overheated) I cleaned out all the dust and upgraded from 2.4 to 2.9 I have it plugged in to a APC

The other systems we have seem to run just fine too. on the regulating transformer but it goes down when we lose power.

I have had my system for a very long time it is a prototype (more of a 3500 kinda)

and started out with the 167MHz CPUs in it. I upgraded to 400MHz the so called bad CPUs return from customers. it has be up 263 days now after I did the OS upgrade.

The up-times here seems to be linked to PG&E outages :(




I cant say the same for any if the linux systems or windows systems. I have. And I like having 12gigs of ram


My biggest complaint is it is heavy to move...

and I have worn out 3 sets of drives...

1 gig then 2 gig I have the 9 gig in there now and they are starting to get noisy so I guess I will have to replace them with the 35gig drives...;)
 

·
Registered
Joined
·
7,137 Posts
Whatever solution you end up picking, just make sure the cut-off voltage and duration before cut-off are adjustable.


You can often get quite a dip for a very short duration when you first power up large amps, or other similar power-hungry equipment. You wouldn't want your relay to trip if the voltage sagged down for a split second.


Kal
 

·
Registered
Joined
·
733 Posts

·
Registered
Joined
·
3,557 Posts
I would highly recommend a line regulator to solve this problem. UPS' don't typically do line regulation unless they're specified as a line reg/UPS. In both UPS' and Line reg's, they have threshhold voltages that determine min/max points of normal operation. When this min/max threshold is reached in a UPS, it cuts the line and switches to internal batteries. When a Line reg sees the line dropping or spiking, it boosts its output or clamps it to compensate. However there's a minimum point of compensation reached on line sags and it's generally dependant on current draw. In other words, if you have a Line reg that will maintain a 110VAC output as low as 80VAC input, the duration on this compensation in inversely proportional to current draw at the time of incident. In English, the Line reg will be able to maintain that 110VAC output at a current draw of 1 amp a lot longer than it will be able to if there's a 10 amp draw. How long? - hard to say and it varies from product to product, but the safe bet to maximize the protection desired is to buy one that has at least 20 - 30% more capacity than the maximum you're likely to need. Try dropping in on Tripplite's web site for more info. Incidentally, for clarification, line regulation is COMPLETELY different from line conditioning - line conditioning is just filters and surge suppression. The amperage you need will likely exceed your stated budget, but I'd recommend saving up for it if you truly want to protect your stuff... ;)
 

·
Registered
Joined
·
2,606 Posts
Discussion Starter · #16 ·
Arrgh. I have two of these on the way: http://www.panamax.com/products/prod...sp?sname=m4300


My idea is to throw a wall wart on a switched outlet and use that to control the trigger input for the Panamax unit. Lets hope it doesn't disconnect due to low voltage during amp power on. :)


If this doesn't work out, I'll look into what Prometheusbound recommended.


Mike, my stuff isn't worth _that_ much that I should have to save up for something like this. But yea, a line regulator would be ideal, but ]they are definately up there price wise. I was hoping I could do this for a lot less than a quality line regulator, as its just a silly relay. :)
 
1 - 16 of 16 Posts
Status
Not open for further replies.
Top