Power brick replacement

Hi!I'm sorry if this is not the best place to ask, but I thought I'll give it a shot as there are knowledgeable people here that might know the answer or point me in the right direction. Please delete or move if it's inappropriate. Thank you.I'm looking for a 6 - 9 volt power brick replacement that apparently was damaged due to a power issue. It also damaged the device it was powering. Are there power bricks or power supplies that would protect the device they are powering from damage due to surges and such? Or would it be better to get a line conditioner?

This location is fine, but more details are likely needed for others to provide sensible suggestions and advice ....

Power bricks or adapters don't usually have surge protection built in. One can buy surge protectors that can be plugged into an outlet, then the device can be plugged into that to obtain protection. One can also buy outlet extension cords that have surge protectors built in that will protect more than one device at a time. Either way, make sure that any one you purchase has a good recommendation, and offers adequate protection. There are several that offer insurance as part of the purchase price that will repair or replace damaged items if the surge protection fails.

Yes, line conditioners as well as UPSs will provide surge protection, but they are usually large and awkward to carry along with a portable device.

Just as a side nite, whole house protection from surges can be provided by adding surge protection at the main power panel. This is especially helpful when one had a lot of things on different circuits that have electronics in them, since that would be more practical than buying individual protectors for each piece of equipment.

Oh, and any device that does not have a ground connection can not provide nor have surge protection. A ground connection is required to have somewhere for the surge to be redirected to away from the protected equipment.

Timothybil said:

Oh, and any device that does not have a ground connection can not provide nor have surge protection. A ground connection is required to have somewhere for the surge to be redirected to away from the protected equipment.

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That is not always correct. Usual you want to protect against high voltage between Live and Neutral and you can easily do that without any ground connection.
The standard device to give surge protection is a MOV (or more) and that can also be mounted inside devices to add surge protection to the device (A few do have it).

In these protections the surges are not redirected, but converted to heat (That is what a MOV do).

HKJ said:

That is not always correct. Usual you want to protect against high voltage between Live and Neutral and you can easily do that without any ground connection.
The standard device to give surge protection is a MOV (or more) and that can also be mounted inside devices to add surge protection to the device (A few do have it).

In these protections the surges are not redirected, but converted to heat (That is what a MOV do).

Click to expand...

Thanks, I didn't know that.

One of my recent reviews was of a surge protector (and a bit more), the MOV's are here:


The 3 MOV's are in a star between Live, Neutral and Earth, this means it will clamp any high voltage spikes between and of the 3 wires. With high voltage it means some point above 1000V, it will not do anything to a 800 volt pulse. Each MOV's is rated for 120J, if the surge contains much more energy (than twice) the MOV's will short and blow a fuse. The protection device will have to be replaced after that (or the MOV's replaced).

Sometimes surge protectors don't help. About fifteen years ago the local electric utility in my ex-wife's home town replaced a transformer in one neighborhood. Somehow, it was never explained to me, they wired it wrong, and instead of putting out the correct local intermediate voltage (If I remember correctly usually around 1300 volts) it put out double that voltage. So all the individual house transformers on that feed did what they were designed to do and stepped down the voltage, but in this case their output was 240/480 instead of 120/240. You can imagine the results, every electrical device turned on at the time gave up the ghost. They laid out quite a lot of money replacing bulbs, stereos, TVs, refrigerator motors, furnace motors, etc. I'm not even sure a line conditioner would have helped in this situation.

Granted, this is a rare occurrence, but it does happen more often than most people think. There is a daily internet blog called 'The Daily Shark' where IT professionals send in stories about strange, wondrous, stupid and foolish happenings in the world of data processing. I can call to mind at least three entries in the last couple years where an electrician either wired a circuit wrong, or a device was plugged into the wrong outlet, with the expected results.

But yes, surge suppressors are a good idea for any electronic device worth more than a few dollars. They are cheap protection for your equipment.

A little bit off-topic here, but mainly meant for solar / backup battery system folk ...

Surge protectors with MOV's don't like the output from cheap MSW (modified sine-wave) ac inverters. So if you plan on using a surge protector behind an ac inverter, it should be a PSW (aka Pure-Sine-wave) type.

On the same topic - anyone using a battery charger (large or small), should NOT be using it behind a cheap MSW type inverter in any case (among other valuable devices) *even if it seems to be working*. It isn't, but you don't know it until it's too late.

Agreed for the battery charger, but I want to clarify upon that for people who may be curious:

If the battery charger uses a decent SMPS to step down the input to something like 12V or 5V (like most XTAR chargers or USB chargers), it is OK to use it with a MSW inverter as long as the SMPS is OK with it (most small SMPS units of reasonable quality will be happy, although they may run hotter). The bad waveform will never touch the charger.

The issue arises with chargers that rely on the characteristics of the waveform to charge the battery. A good example is the classic NiCD/NiMH trickle charger. These chargers use a transformer, backfeed protection diode and resistor at minimum to trickle charge the battery. They rely on the transformer limiting the power to the battery. If you supply then with power from a cheap MSW inverter the output waveform and allowed current through the secondary will change, potentially damaging the charger (overheating) and battery.

TLDR: If your charger has a power brick that outputs DC, and the power brick itself is not a charger (some cheap 12V halogen spotlights use an external DC power brick that is a charger, be careful!) then you can use a cheap MSW inverter. If your charger is an old unit with integrated PSU (especially NiCD/NiMH trickle or lead acid charger) or has a heavy linear transformer like most lead acid chargers, avoid MSW inverters and use a pure sine inverter only.

You are a bit behind the times, it is very difficult to find anything with an old style iron transformer today, just about everything uses a SMPS.
In a SMPS the input voltage is rectified to DC and use to charge a capacitor. The voltage on that capacitor must usual be between 150 and 350 volt for the device to work (All with 100-240VAC input). This means most chargers works fine on just about anything that are near mains voltages.

I do not know why MOV's will have problems with cheap MSW generators, if that is the case I would trow the MSW generator out (MOV's will first do anything well above 350 volt).

Yeah I'm used to seeing bulky transformers in some battery chargers My modern lead acid charger I use to tend to the various SLA batteries I own is surprisingly small and microcontroller controlled. I think worrying over MSW waveforms damaging chargers with today's modern designs is something that will be extremely uncommon. The only linear chargers I have are a couple of old NiCD chargers.

Agreed with the MOVs. I cannot see from an electrical point of view why a MOV would be unhappy with a properly functioning MSW inverter that outputs a waveform that is not exceeding the correct voltage levels it should be generating. Additionally, most devices with a good SMPS will have MOV protection built into the power supply and they still even today sell UPS units from reputable manufacturers that generate MSW AC. The reputable companies would not be selling them at all if they damaged MOVs in power strips and PSUs!

I'm not only talking about the tiny UPS's like the 500VA Back-UPS from APC, but also the larger ones like the Back-UPS Pro (1000VA+) that is still sold as a current product. They output MSW; you have to move up to Smart-UPS to get pure sine wave. I have been using the larger Back-UPS units for years with MOV protected power strips (and PSUs) without incident.

Thank you for the replies! I've been away for a while and couldn't post. So I got a Tripp Lite Isobar 2 outlet surge protector. Do you have any suggestions for the power brick? I know companies such as Seasonic or Sparkle make good quality power supplies for computers but I have no idea about power bricks. If there are good quality brands making those then I'd want to get one of those.

Double post: the web site is very slow. I may have clicked the Post button twice. My apologies. Is there a way to remove it?

Only thing I can think of with MOVs from an electrical perspective, is if the "steps" in a "sinus approximate" curve overshoots significantly on each rising edge. That wouldn't just be bad for the MOVs though.

I have been plugging my important stuff through a quality Surge bar for many decades. Tripplite iSOBAR, APC NET and others on the market. It is important to view the Joules rating on no so well know names as well as clampling voltage with response time. Lower is better and Joules should be 1000 or more. There are a quite a few lower cost ones on the market than the two I mentioned at the beginning now. No real excuse to not protect your TV, Computer, Stereo sound system or other expensive devices. Computerized refridgerators, gas stove have costly control panels in them. I purchased one recently for my gas stove since I converted from an electric one. Brand name with excellent spec's at ~$15. Controller board is probably $200 or more if it went.