Yes, when you are immersed in water it takes a much lower voltage to create dangerous currents in your body.
The real issue about it all was not that there was a dock somewhere that had a grounding problem. The issue was that the installations they looked at all were up to code, both local and NEC and the problem still existed.
Like I said, the problem was not an installation, but that the codes are not up to dealing with this issue.
Now please explain how this relates to the issue at hand?
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setup is at the moment but driving with a DC current should be pretty much as simple as PWM. You talk about adding a choke. I'd be willing to bet i f you look at the resulting circuit it is a short stone's throw from being a DC/DC converter.
noise you can stop with a simple filter.
taillights on so many cars. Cadillac was the first car I noticed it on man y years ago and have always been the worst offenders with huge taillights o n some of their vehicles. More recently they seem to have changed their de sign, either by bumping up the frequency or by using DC.
re is a distinct effect from replacement LED turn signals blinking too fast because they don't draw enough current for the blink circuit to work corre ctly, called hyper flashing.
a current drive very easily.
The current source is just a current source. The bidirectional aspect is w hat your H drivers are for. I thought you were using PWM to control the br ightness which causes the issues I mentioned. As long as the rate of switc hing the polarity of the drive is fast enough you won't have a problem with flicker. If your current source is controlled, it can ramp up and down th e current for each phase and you will get very minor harmonics from the pol arity switching.
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We've been talking about maybe chopping at 100 Hz. A few us of gate slowdown wouldn't wouldn't add much dissipation.
But the whole thing is silly. A string of fairy lights PWMd at 100 Hz is not going to bother anything.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
See above.
Sorry, I thought you were replying to me.
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Instead of guessing, you can:
Measure it with a log periodic antenna, example:
Or calculate, as others mentioned
Or simulate, plugging in the waveform and using the attack/decay properties defined in the final test in the standard
Cheers
Klaus
Ah - I see...
The current source would have to switch in time to the PWM though to drive the alternate sets at different brightnesses.
is what your H drivers are for. I thought you were using PWM to control th e brightness which causes the issues I mentioned. As long as the rate of s witching the polarity of the drive is fast enough you won't have a problem with flicker. If your current source is controlled, it can ramp up and dow n the current for each phase and you will get very minor harmonics from the polarity switching.
The current source has to ramp down and up to give the resulting signal low harmonics.
Current output /--\ /--\ / \ /----\ / \ /----\
-/ \-/ \-/ \-/ \- Phase 1 2 1 2 ________ ________ _________/ \________/ \_ H bridge control
If you want to get fancy you can slew at adjustable rate to round the corne rs further reducing the harmonics. The PSU will be whatever you want, line ar or switching, but there you don't have to worry about RFI if it is prope rly designed. The current can be sensed by a small resistor in the ground leg and otherwise the entire supply is the same as a voltage regulator.
For a fixed rise time many PSU chips have a slew rate control via a cap. T o directly control the output current a variable reference voltage can be u sed, say from an MCU DAC output... the same MCU that can control the H brid ge.
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