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5 sats \ 3 replies \ @gnilma 27 Jun 2023 \ parent \ on: What 10+ year old tech are you still using? tech
The electronics in a car already runs on direct current (DC) sourced from the 12V battery and doesn’t need diodes. All the diode does is pass through the current when the circuit gets turned on. I don’t see how it would extend the lifespan of any bulb. But I guess you can always try to test it out if you want to find out?
Yeah, it didn't make much sense to me, either. The book was from mother earth news in the 70s or 80s, so take from that what you will. It did have a lot of very good, field tested factual information about electric motors and batteries for diy electric cars, so I'll forgive him for printing an old wives tale. He had a pretty good book on wind mills and spinners as well, which is of course a related field.
I think the "proof" he used for his diode theory was something like this. But I seem to remember it being an Edison bulb he was talking about, and he claimed that only using DC was why the bulb lasted so long. Silly theory, I know. Which is why I never looked into it.
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Oh wait, I misread your original comment and thought you were talking about regular cars. These DIY electric cars, do they run on batteries? If so, what type?
Regarding the diode theory, it might have some merit if the bulb was connected to an alternating current (AC) circuit, which most electric grids run on. The diode would only allow 1 phase of the AC to pass through and filter out the opposite phase, causing the bulb to turn on and off very quickly. For North American grids where we run 60Hz AC, that's about 8.3ms (1/60/2=0.0083) on and 8.3ms off; fast enough for the naked eye to not notice the flicker. As such, it keeps the bulb off for half of the time than if it was full AC passing through it, which might reduce the amount of heat produced and might help prolong the bulb's lifespan. Again, just pure theory, have not tested it, so I might be wrong.
But if those DIY electric cars run on DC batteries, I really don't see how adding a diode to the circuit would help prolong the lifespan of the bulb, whether it's tungsten bulb or not.
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Yes. He was talking about AC. And his reasoning was basically what you just described. Been about 20 years since I read the book, though, so my memory is fuzzy, at best.
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