Recent content by avicenna

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    I Getting a reduced voltage from a fixed secondary voltage of a transformer

    My apology. I am no expert, just asking a theoretical question about putting an inductor as load to a transformer. My questions now all cleared. I just built a crude home transformer for some purpose. I wound 100 turns AWG 19 copper wires over a 16mm upvc tube as secondary. My primary 100 turns...
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    I Getting a reduced voltage from a fixed secondary voltage of a transformer

    Say the choke has sufficient/many copper turns and we approximate ignoring R; R= 0. So Z = 2π * 50 * L ohm may (generally) be high. So secondary current I = 12 / Z generally low. Primary current = I * 12/ 240 (earlier post typo as I * 240 / 12) is usually within limit of primary current rating.
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    I Getting a reduced voltage from a fixed secondary voltage of a transformer

    Thanks. Very helpful. Isn't it true that a good choke/inductor has very high impedance? So the current drawn "I" would be very small. Primary current about I * 240/12. NOTE: your typo error. It is 50 ohm
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    I Getting a reduced voltage from a fixed secondary voltage of a transformer

    1) I have a "choke" with many copper windings on a soft iron core. I connect it to the 12V secondary of a mains transformer. I measure the voltage of the choke with a multimeter. What is the value and why? 2) I want to light up a 6V filament lamp. My supply is a 12V from a step down...
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    B Will My DIY Capacitor Light Up a 6VAC Bulb in Series?

    I realize my idea about my capacitor experiment wrong. So I don't need my capacitor for now. Thanks for the advice.
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    B Will My DIY Capacitor Light Up a 6VAC Bulb in Series?

    Thanks. But I am not at the level to try this yet.
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    B Will My DIY Capacitor Light Up a 6VAC Bulb in Series?

    OK. The display box in my linux system is only 4 digits wide; I have to use the right arrow key to get the rest of the digits! I reduce the font size and got the full value!
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    B Will My DIY Capacitor Light Up a 6VAC Bulb in Series?

    Yes, I think no way for super capacitor this easy. About the site, I think really bad. My entry was 200pF, 50Hz only
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    B Will My DIY Capacitor Light Up a 6VAC Bulb in Series?

    Is there a simple way to build a home 100 - 1000 μF capacitor? Best as a parallel plate capacitor with small area plates.
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    B Will My DIY Capacitor Light Up a 6VAC Bulb in Series?

    My estimate: capacitance = 200 - 400 pF. reactance(1/(2πfC)) = 16 MΩ This site, All About Circuits has an online calculator: https://www.allaboutcircuits.com/tools/capacitor-impedance-calculator/ Gives impedance to be 1591 Ω ; I think wrong. Bad website?
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    B Will My DIY Capacitor Light Up a 6VAC Bulb in Series?

    Thanks.
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    B Will My DIY Capacitor Light Up a 6VAC Bulb in Series?

    Say I build a parallel capacitor from two 10cm x 10cm aluminum foil with one sheet of writing paper in between as dielectric. I press the foils together with a weight and a flat piece of plastic/glass. I can power on a 6VAC incandescent bulb with a 6VAC power supply. Now if I connect my...
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    I Very bright geo satellite in my night sky?

    You are dead right! The night star is Jupiter. I look for the star at 9pm tonight but the Singapore (not Ecuador) sky was cloudy. At 11.30pm, the sky cleared and there was the lone, but bright star. It was clearly shifted west by an appreciable arc , say 20-30deg. What confused me...
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    I Very bright geo satellite in my night sky?

    If it was Jupiter and Venus, then it was a strange coincidence that I watched at 10pm and 6am when one planet replaced the other. I will watch tonight at 9.pm and follow up after to see if it sets. They almost have the same brightness, the brightest stars I have ever seen.
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    I Very bright geo satellite in my night sky?

    If it is a planet, it would move with the stars. But it is not moving. I will try watching at 10pm and then 3am tomorrow. At 6am today it was "there".
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