Arild Jensen wrote: > [EMAIL PROTECTED] wrote: >>> I'm not an engineer like some of you, but I run my computer on a >>> square wave inverter (as in cheap) and have no problems. I perceive >>> that as long as the battery is in the computer it absorbs (filters) >>> whatever comes in and cleans it up enough for the computer to handle >>> it okay. This may not be great for the long term, but I've had no >>> problems. > > > > DC-DC converters are in effect also inverters with an added > rectification step included on the output. This is how you get the DC > from AC. So you cannot argue that a DC -DC converter is inherently > more efficient than an inverter.. > You can rectify a rough MSW output to give you rippled DC but it > will still emit RF interference. > you have to look at individual brands and models to determine anything. > I understand how they work, I've actually build a couple of small ones. My reasoning is based on the fact that no device is 100% efficient. So if you have an inverter that is 90% efficient and a power supply plugged into it that's 90% efficient the the efficiency of the system is .9 X .9 or .81. If you only convert from 12 to 18 volts with a single DC/DC converter and it's 90 % efficient. That's assuming a lot I know.
The other point is that most laptop bricks are <100 watts. Typically 70 or so. To use a 600 watt or larger sinewave inverter is inefficient. A 600 watt inverter might be rated at 90% efficiency but that's only if you are running it full tilt. At lower current draws it is less efficient. That's due to the fact that at zero current draw the inverter still is drawing some current. Anyway it's probably a moot point. I agree with the RF noise however I haven't experienced a problem with the Targus converter. I run CW and PSK31on HF using that setup and don't have noise from that device. However I cannot use the radio at all from my dock. There are more rf sources in that marina than you can shake a stick at. They all go away about 1/2 mile down the channel. Jim. _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [EMAIL PROTECTED] To unsubscribe send an email to [EMAIL PROTECTED] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
