Author Topic: Bi-directional Watt Meter  (Read 2598 times)

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Online dmills

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Re: Bi-directional Watt Meter
« Reply #25 on: October 03, 2018, 08:14:36 pm »
There is sometimes a tendency to do in many kB of code what can be done in trivial hardware with less thought involved, I hope Widlar would have approved.

Do make good and damn sure that this thing actually does what you need, I have not exactly tested it. There is a bit of a dead band around voltage zero crossing before the opposite transistor turns on, and I think the bipolar version is actually a switched halfwave rectifier in effect....

Mosfets (but watch for the body diode) might make better switches being as a mosfet in conduction is bidirectional, or even jfets, but I had one hell of a time getting that to work without some small offset in spice, and the things tend to be horribly badly matched. 

Finally, remember that spice is good at telling you what will NOT work, but can be fairly poor at indicating what will, you need to actually build the thing and verify it.
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Offline snipersquad100

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Re: Bi-directional Watt Meter
« Reply #26 on: December 10, 2018, 06:06:26 pm »
I'm Back  :phew:

Offline Miyuki

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Re: Bi-directional Watt Meter
« Reply #27 on: December 10, 2018, 07:58:52 pm »
Yes, those turning disc meters were great, I wish I still had one.
I still have one  :bullshit:
They are still used here in countryside with overhead power lines as they are fairly robust  :bullshit:  Wonder if it is still cheaper to made than digital one

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