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Dynamotors are old technology. Really old, we're talking WWII and before here. I've been told that they are quite inefficient, like 65% net. They're also quite heavy.

I use a little solid-state inverter I got at BJ's to power stuff in the car; it converts 250 watts and cost $29.95 two or three years ago. Plastic case. Weighs maybe a pound and a half. I've used it to power my computer for hours with the engine off; the battery seems to handle it fine. That's about the most you can draw from the cigarette lighter, at least in my car. If you need more than that, you need to do the kind of mods you were talking about.

Compared to the solutions that were available when I was a ham, 40 years ago, it's miraculous. Tiny, cheap, light, quiet, and efficient. Doesn't get hot. Doesn't buzz or hum.

If they had 3500 watt aftermarker alternators back in 1969, they probably have 10 kW alternators (or more) today of the same size. Electrical machinery has gotten a lot smaller per unit output then it was then, although the shrink ratio isn't as much as for chips (if it had kept up with the shrinkage of circuitry, you'd be able to hold a 10 megawatt alternator in one hand; finding a 15,000 horsepower prime mover to hook it to might be a bit of a chore).

I don't know. I know you bolted it on your engine and had an extra pulley and belt to drive it. Dunno if they had any 10kW ones now or in 1969. I might have a scan of it somewhere. I also have a picture of an alternator like that from 1959 in an old radio book.

Dynamotors are old technology. Really old, we're talking WWII and before here. I've been told that they are quite inefficient, like 65% net. They're also quite heavy.

I remember seeing them used for radios. I remember a John Wayne movies where Wayne and his Air Force crew were down in Northern Canada, their DC-3 (C-47) crashed and they still managed to keep their radio running for a while and when they had to transmit, they had to kick the dynamotor on. Their battery eventually died and they had to use the handcrank emergency generator. They also had a problem with an AM station from Montreal interfering with their radio compasses. Eventually Ed Nolan and Slim Pickens did find them as they used their DC-3's (C-47's) to search for them.

I use a little solid-state inverter I got at BJ's to power stuff in the car; it converts 250 watts and cost $29.95 two or three years ago. Plastic case. Weighs maybe a pound and a half. I've used it to power my computer for hours with the engine off; the battery seems to handle it fine. That's about the most you can draw from the cigarette lighter, at least in my car. If you need more than that, you need to do the kind of mods you were talking about.

I work as a delivery driver for an auto parts store. We have those inverters, 75 watts, 400 watts and 700 watts I think. I'd like to get the little one, would make a good source of laptop power. B-)

Compared to the solutions that were available when I was a ham, 40 years ago, it's miraculous. Tiny, cheap, light, quiet, and efficient. Doesn't get hot. Doesn't buzz or hum.

I know, I do admit there is charm in the old stuff, but I do like the compactness of the newer stuff.