As you are an electrical engineer, would my plan to buy a UPC power supply to smooth out the current for using with computers and other sensitive electronics be a good idea? Would this generator kill my direct TV receiver or a DVD player without it?

I love that we can post here and find out just how far we can push a piece of equipment like this. What its limitations and uses really are. What a great resource Arfcom has been!

According to internet scuttlebutt, using TC-W3 two-stroke oil is another trick for keeping the plug cleaner. Supposedly, it burns more completely than "ordinary" 2-stroke oil, leaving less residue behind.

Very interesting that you mentioned that. I bought Pennzoil TC-W3 rated oil for my saw years ago and was planning on using it with my generator. I just figured that it said it exceeded the requirements of the manufacturers and my parts guy said it was good stuff that I might as well give it a try.

Thank God they are both 50:1 ratio.

I'm not an "expert" on any of those things either, and I don't know much about them. In general though, these devices actually run off DC internally. They either have a wall wart or an internal DC power supply, or some combination, to get the DC needed internally. Most times the DC power supplies don't really care much what the incoming waveform looks like, as long as it is not way off. Defining "way off" is a tough thing. Mere frequency variations are usually not an issue. Even changes in voltage usually are not an issue, as they are often designed to accept power from a wide range of power sources. Its not unusual for the power supply to be rated as 47-63 Hz, and 90-250VAC , or something along those lines for wall warts.

I don't know how "sensitive" your stuff is, but often the sensitivity to power line fluctuations of this kind of stuff is over played to sell expensive power conditioning gear that often serves no real purpose.

Usually, cheap UPS's are of the standby variety. You are actually using line power most of the time and it switches to making power off the batteries only if the incoming line power is interrupted. Many, but not all, standby UPS's incorporate some level of surge suppression and filtering on the line power so there is some protection against transients. Generally if the incoming voltage is too high or too low, the UPS also switches the output to internally generated power. I think some may also switch if the frequency is a problem. Point being that unless the thing switches to internal power, a standby system won't do much to protect something that really is sensitive to power fluctuations (other than some minimal filtering and surge suppression).

More expensive UPS's are of the on-line type. The line power is brought into the battery charger section which continuously charges the batteries and the DC is made into AC from the batteries all the time. There is pretty good isolation from the line on these things, so there is good protection from transients and other power line disturbances.

There are variations on these as well.

If you think you need to protect your electronics from the output of your generator, an on-line type UPS is a better choice. They cost more, but these days its not that big a deal.

I would point out that if the waveform is jacked up enough from the generator that some UPS's will not take the incoming power even to charge the battery.

I would also point out that it is not unusual for batteries in UPS's to need regular replacement. We had one customer that had several hundred small, cheap UPS's in their plant. Virtually all of them failed within a few years due to battery issues. Small UPS's are one of the more common points of failures in computer systems. It's usually not a big deal because the small cheap ones are normally not installed on anything really important. If the average desk top PC shuts down due to UPS failure, its not usually a big deal, as you can just plug the thing into the line until the UPS is replaced.

My suggestion would be to call the tech support line at the the UPS manufacturer you are thinking of using and ask them about your application. They are usually quite helpful. Personally, I do mostly industrial systems and I have mostly gotten away from using UPS's at all as they just create a common point of failure that I don't want to add to my system. For my kind of stuff if the power goes out they can't run anyway, so it really makes little difference.

Thank you for your response! I had no idea that some of them did not run through the battery continuously.

What about line conditioners? They are actually cheaper and are supposed to step the voltage up or down to give smooth power. They may be a joke for regular line power, but would they have a real point for this situation?


I will definitely wait to get my generator warmed up before running anything so it smooths out.

Depends on just what you mean by line conditioner. It's a term that is used to describe a wide variety of equipment.

I used to be a big fan of ferro-resonant transformers. Over time though, I realized that virtually everything actually runs off of DC and the DC power supplies produce very solid power so they seemed kind of redundant. They also generate a fair amount of heat and I have to get rid of that heat somehow. As the panels shrunk on the stuff I designed, I had to make a lot of design choices, and ferro-resonant transformers no longer seemed like a good general purpose choice. Basically all they can do is reduce voltage variations anyway, and most DC power supplies really don't care much about minor line voltage blips.

I used to use a lot of RFI filters as well, thinking I was doing some good. One time a vendor brought in a scope and a transient generator and let me play around with it for a couple days. The ferro-resonant transformer did not do a very good job of dealing with the transients. It was able to reduce them, but did not get rid of them. The RFI filter actually started ringing when I applied the transient generator.

You have to remember that today's electronic equipment is much more solidly designed than in the past. It may not seem like it, but modern electronics are pretty robust. A lot of it has to do with how much heat they generate. Electronics of all types are affected by heat. The hotter it is, the less life you see from the device. So just by reducing the heat, or by more effectively getting rid of the heat that is generated, you can dramatically affect the lifespan of typical electronic equipment.

One problem with DVD players, TVs, and stereos is that people put them inside cabinets where they don't cool very well. I am kind of amazed that more people don't put a cooling fan on the back of their entertainment centers to draw out the heat. I would not be surprised one bit to find that a $5 fan would save more electronic equipment than any UPS or other power conditioning equipment.

One thing I do suggest is a whole house surge suppressor at your service panel. Transients coming into your home (such as can be generated by lightning or grid switching) can do a number on your stuff. Most stuff is pretty resilient, but every time it takes a hit it gets a little damage and over time it adds up.

I wish there were definitive answers to your questions. I don't think there are. Power conditioning equipment of whatever type, including UPS's, are unlikely to harm the equipment they power and may provide some level of additional protection, so you might want to get something, if only to make yourself feel better about it.

The thing with power problems is that it's very difficult (really close to impossible) to tell whether they caused equipment to fail or whether the failure was just a "normal" failure or some kind of defect.

I am not terribly concerned about running a lap top on my genny. I can always just charge the battery with it off and then fire it up later.

I think later I will just take a chance and try running my direct TV off it and see if anything explodes. Its a $50 chance.


My computers are rated for incoming voltage from 100-240v. I just did not know how fluctuations would affect things. I figure if I am worried, not running the processor on the genny would avoid issues.

Thanks for the responses. Its been very helpful. There is risk in everything. Its great to have some education on those risks before taking them.



ETA: I am running a small tube type tv and my direct TV receiver on it right now. It was a little weird getting started but now its running great! The receiver didn't want to fire up with the remote. Hitting the button worked and now it turns on and off just fine.

The genny is not as smooth as it was with the 500 watt work light. I figure its the volume changes and brightness changes in the tv. Still cool as hell for $79!


ETA:I decided to leave it running to break in some more. I can hear it running smooth as silk with the work light. I wonder how many watts the tv and receiver were? I doubt they were very much.

ETA: It has been running for 4 hours so far. I had it running for a couple hours last night. I figure I will run the whole 2 gallons of gas for my break in. Not only for break in, but also to use up the gas.

DC power supplies sometimes end up with rather odd looking incoming current waveforms. It might be that the generator finds them moderately offensive.

The light is a pure resistive load and is the nicest kind of load you can have.

Harbor Freight had 20% coupons in my Sunday paper. I plan on getting one or two of these.

Does anyone know if we can hook these together like the Hondas can do?

These generators have one single 110v plug. No provisions unless you are an electrical engineer.

We'll see if this worked better....

Not even if you are. The Honda units have an inverter section as its output, and they can be easily synced together electronically.

The only way to sync the HF units would be to get them running at the same exact speed and at the same phase angle before tying them together.

However, it should be possible to rectify the output of two (or more) generators and tie them together as the DC input of an inverter and let the inverter supply the AC. Might be an interesting project. Not real practical, but maybe fun.

Well I was thinking about running out and picking one of these up yesterday, got on the HF website, and the dang thing was listed on their main website on sale for $129 now.

I checked a flyer that runs May 28-June 24 on their website and it is listed at $109, but it seems to be off the $99 sale.

I am sorry I left my copy of the online price at the harbor freight store. I would have happily scanned a copy and sent it to you.

I wonder if anyone else has a screen shot of that add they can send you?

Did you call the store to find out what the current price is? that's your best bet.

The last few times I have been in harbor freight the generator has listed for $109, so you will be better off using the 20% off coupon and getting it for $87 than the $89 coupon.

If money wasn't so tight, I would buy an extra one as a spare, or to sell at a 100% markup after a storm.

Print this coupn and take it down to store. You must act fast as this one expires on 6/16/10
Price is $89.99 with this coupon! I may have to go get another...

www.harborfreightusa.com/html/MagazineLanders/5-outdoor/images/15.jpg

Thanks to everyone for the heads up on this generator and everyones review. I just ordered one online for the $89. I would have to drive a hour away to pick it up so I just had it shipped for $11. Ill put my review on here after I recieve it but looks like it will be 1-2 weeks.

Hello all,

I recieved my Generator on 6-19-10...yesterday! I was expecting it to take atleast one week to show up since I assumed it was a "heavy item." Must say please with the quick shipping. I just broke it out today and fired it up. I ran it for about an hour with only a small fan and a 100w light plugged in. I was suprised by how quiet this ran. For a cheapo i thought it would be pretty loud but wasnt too bad. Of course I dont have a honda or anything to compare. This will fit my needs just right. I plan on using it for when I go camping and when the power goes out. I have a bigger generator but it also uses a shit ton of gas. with this little one I dont think I will be using the big one much at all when the power goes out, unless I just want to show off
For the money I would buy again in a heart beat!

I just ran my generator for another 3 hrs on my way to finishing off my second tank of gas. This thing runs like a top! Its quiet enough that I left it running for an extra hour because I forgot it was running. The air conditioner covered the noise easily.

5 tanks of gas to break it in is a heck of a lot of run time. My next 3 tanks of gas will be premium on recommendations of some good folks here. I will try out some of the Echo synthetic blend and see how it runs.

Anyone have a Harbor Freight coupon link that's current? I got a flier that shows them for $99, but if I can save more, I will.

Thanks

Print this and take it with you!

Used mine for a total of about 5-6 hours. Took it camping with me on July 4th weekend. Worked out great. Nice to have fresh brewed coffee when ur tent camping... Probable pushed it harder than I should have before it is broke in... My coffee pot is 800 watt. Oh well it worked just fine and I was a happy camper. I have no complaints so far and doubt that I will, seems to be a great little unit for the price!

Thanks very much.

Does anyone have a established runtime/max output for a tank of gas? I'm curious about the total kwh potential per gallon for one of these generators.

Fyi, I was just cruising Harobr Frieght website and these generators are back at $99. Plus you can use the 20% coupon...