¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io

Re: WN4ISX made a mistake!!!!


 

¿ªÔÆÌåÓý

Well, if the switch turns on when the AC is at a peak voltage, the dV/dT will be VERY large. xC will be very low as a result.

Donald.

On 12/17/24 18:25, wn4isx via groups.io wrote:

Hum. Never considered that, I don't doubt you but will the instanious current ever exceed the Xc?
?
It feels like the maximum current can't exceed the Xc.....and yea feelings are important but engineering is about science and getting the math right backed up by real world experiments.
?
I just spent 30 minutes working the math several ways and can't come up with a fast transient from 60Hz, time for real world experiment.
?
Sooo I could add the resistor, or, one of the two dozen 30A zero crossing solid state relays I've been trying to come up with a reson not to send them to recycle, or....
?
I used a similar scheme with a #47 light bulb, AC mains in, capacitor, #47 bulb, neutral, for at least a decade from 1960 until 1970 as a pilot light for a radio. I'll accept the resistance and inductance of a #47 bulb is very different from a string of LEDs.
?
This is something interesting to test, I have a Tektronix CT-1 current probe, bandwidth? 20kHz to 1GHz.
My scope has specs claimed to be good to 200, it will display 144MHz 2M signal with no obvious distortion.
?
0.5uf, 60Hz has an Xc of? 5305ohms. I'll measure it two ways, one direct AC hot to capacitor line through CT-1, to nuetral, then AC to capacitor to 100 ohms wire through CT-1, to neutral and see the max current peak on the scope.
?
Ought to be interesting.
?
And I'll use Teflon wire rated at 2kV for the pass through wire through the CT-1.??

Join [email protected] to automatically receive all group messages.