Safe Power for electronics - Page 1
Forum section: electronics / beginners

author: Avpassion
author_rank: Newbie
timestamp: April 23, 2019, 07:13:55 am
content: I’m in the process of a move to an area which I’ve been told has regular power fluctuations and a few power cuts as well.I have been researching how to provide clean and safe power to my electronic components which would include a Denon receiver, 2 Power amps, a Blu-ray player, Projector, gaming console etc.I am contemplating the below options:Option A: Mains to a Voltage Stabilizer to Power Condtioner(Furman) to the electronic componentsOption B: Mains to an Online UPS(APC) to a Power Condtioner(Furman) to the electronic componentsWould one of these work? Or is there a better solution to consider?

author: jeroen79
author_rank: Frequent Contributor
timestamp: April 23, 2019, 11:21:48 am
content: Before buying anything I would first determine how often and how much the power fluctuates and how often and how long the power is cut.

author: DDunfield
author_rank: Regular Contributor
timestamp: April 23, 2019, 02:01:43 pm
content: I live not quite in the middle of nowhere (you can see there from here), and I too deal with unreliable power.Not only does it fail several times a year (some years "many"), but it often "flails around" as it fails or comes back, resulting in brownouts and short on/off cycles.At one time I had many small UPS, but I found that keeping them tested and in working batteries was a lot of bother and I was often less reliable about this than the power.What I finally settled on:- Everything I care about is on a good quality surge suppressor.- For things that are OK with a sudden/unexpected but clean power-off, I built little "power controllers" which function like a self-hold relay.When the power goes OFF, it stays OFF until I deal with it.- For things that don't want to be suddenly powered OFF, but are normally off when I'm not present, I use standard "desktop" UPSs, so I can just shut down when power-outage.- In my equipment room, where my server and several other things that are on all the time and/or must shut down properly reside:I have a big APC UPS running off a lawn tractor battery. Lasts longer and cheaper to replace than the gell-cells, but you need to tweak the charging circuit and have external venting.I also added forced air cooling when running on battery and put a 20A circuit breaker in the battery line (this will depend on how much power your equipment draws).To manage it I built a custom STM32 based control system:- Monitors UPS to determine when on-battery.- Controls the UPS shutdown signal.- Has large solid-state relay to defer returning power to the equipment.- Monitors the 5V rail of the server to determine when it is ON.- Modified server adding opto-isolator and connector to allow STM32 to "push" the power-button. This is set up to initiate an orderly shutdown of the server.When power goes out:- If outage is <5mins, STM32 does nothing USP keeps everything running.- If outage is >5mins, STM32 shuts down server, and once it has powered OFF, shuts down the UPS (killing it's own power)This also "unplugs" the other network switches, bridges, interfaces etc. in the equipment room.When power returns:- USP comes back online automatically.- solid-state relay remains OFF, blocking power to all but the STM32- Once power has been stable for 30 mins, STM32 enables power to all equipment, then power-on the server.- If power fails before 30 mins, shutdown UPS and wait for it to come back on again.- If power fails after 30 mins, go back to "When power goes out".This has worked really well, and I no longer have to worry about the server & equipment when I am away from the premises. I've not had a single problem with the full-time equipment since.Dave

author: radiolistener
author_rank: Super Contributor
timestamp: April 23, 2019, 02:17:53 pm
content: most of the nowadays electronics has switching power supply which can accept mains voltage in very wide range from 100 to 250 V for example, so I think it should not be an issue

author: Avpassion
author_rank: Newbie
timestamp: April 23, 2019, 02:42:19 pm
content: Quote from: jeroen79 on April 23, 2019, 11:21:48 amI already have all my electronics. I’m in the middle of a relocation from one country to another due to work. My existing place did not need any safeguards as power was stable. But I’ve been warned that my future destination has power issues, hence the question. Fluctuations happening at least a few times every week, with power cuts(mostly short) a few times every month.

author: Avpassion
author_rank: Newbie
timestamp: April 23, 2019, 02:49:00 pm
content: Quote from: DDunfield on April 23, 2019, 02:01:43 pmThank you Dave. You’ve given me a lot of things to consider.All my electronic equipment will be powered up only when in use, which will be for a few hours every day. So considering it won’t be on 24/7 makes some of the safeguarding precautions easier.A circuit breaker is already installed in the apartment, and I will discuss some of your suggestions with a local electrician.

author: Avpassion
author_rank: Newbie
timestamp: April 23, 2019, 02:53:26 pm
content: Quote from: radiolistener on April 23, 2019, 02:17:53 pmI understand that, but considering my Audio/video equipment value easily tops US$30K, I’d rather take a few prudent steps than be sorry.

author: Benta
author_rank: Super Contributor
timestamp: April 23, 2019, 06:49:17 pm
content: A constant-on UPS which will run from either mains or battery is the way to go. The output is constant and practically distortion and noise free.As opposed to the "mains direct through / backup switch in" types.They're pricey, though.

author: james_s
author_rank: Super Contributor
timestamp: April 23, 2019, 06:54:36 pm
content: Relatively inefficient too I would think, you've got your entire load going through something that is stepping the voltage down to battery voltage then back up to mains voltage. It would be interesting to see a comparison of actual losses for various UPS units. The steady state draw is one reason I got rid of the UPS I had, another reason was I came home one day to find it smoking and melting itself apart.

author: Benta
author_rank: Super Contributor
timestamp: April 23, 2019, 07:37:37 pm
content: Quote from: james_s on April 23, 2019, 06:54:36 pmNo, that's not how they work. It's basically an AC/AC inverter with the option of injecting battery DC into the AC output inverter.Efficiency is not bad, I've seen figures over 95%. However, they're normally 10 kVA or larger, which might be overkill here.

author: Avpassion
author_rank: Newbie
timestamp: April 24, 2019, 02:43:39 am
content: Quote from: Benta on April 23, 2019, 06:49:17 pmThat was one of my options - An Online UPS. Yes they are quite pricey!

author: Avpassion
author_rank: Newbie
timestamp: April 24, 2019, 02:49:39 am
content: Quote from: Benta on April 23, 2019, 07:37:37 pmHowever, they're normally 10 kVA or larger, which might be overkill here.I was considering a 6kva which would cover the maximum power(Watts) required for my equipment.