Some of the smaller (5kW) generators are available with automatic voltage regulators and some without.
For tools and general construction lighting, the unit without has been doing the job for many years reliably.
Now construction trailers want to run computers off these small gens. Anyone have power quality information, as to how much better the automatic voltage regulator keeps the voltage steady during electrical loading and unloading.

Best bet is the small VR's. A 350 watt can be had for about $45-$50. It can handle puter, prntr, modem, scanner, etc and becomes a part of system. I used this method in 1985 with the IBM desktops. They were very sensitive to voltage. Also, check the specs of the puter. There are a few that have built-in VR's.
Rowdy

Specifically for the “sensitive” {computer?} equipment, I would get a dealer to let you to try out something like a Honda EU1000i Inverter/Generator at the site with intended loads.

rowdyrudy,
Are you suggesting adding a VR to a gen that doesn't have one? I think that would be over a feild persons head.
Bjarney,
Thanks for the suggestion, there is one service connection and the inverter models stop at 3kW max, although they claim they can be paralelled $$$.

Ron:
The small VR is a free-standing unit. It has recepts for equipment and a cord/plug to catch an outlet. It stays with the puter, not the genset.
Rowdy

Ron,
When you buy gensets for this purpose, look for gens with a Total Harmonic Distortion of less than 5%. It is not so much the voltage but the wave form that messes up modern electronics. The cheaper Colemans can have an actual Square wave, or even a half wave rectifier on them that will not allow the semi-conductors to semi-conduct.

Also, don't try to charge a battery with them IF it works, it takes HOURS to do any good at best.

Unfortunately, the gensets do not have THD or similar ratings available from the manufacturer.

rowdyrudy,
Now I'm confused (doesn't take much). What small VR are you talking about? An small online UPS?

Ron:
One source is Directsalesinc.com. The 350 watt is stock #AR350. I think they have units up to 5000 watts.
Rowdy

Tripplite makes line conditoners
go here www.tripplite.com

87 to 140 volts in, regulated to 120v nominal
I have one and it works great on a generator, plenty of usage back in the ice storm in 98.