I found this converter-circuit on the Internet. I will use it to power an IR2153, which contains a 15,6V zener. I chose to use it because of the large losses of a resistive dropper. The unmarked voltages are unknown. Diodes- high speed (BA159, UF4007 etc.)


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    \$\begingroup\$ very dangerously \$\endgroup\$ – Trevor_G May 17 '17 at 16:54

Very inefficiently: The 0.22uF cap and 100 ohm resistor create an RC oscillator, periodically turning on BUX85. The 4.7mH inductor smoothes out the voltage somewhat, and the zener tries to make it a regulated 15ish volts. Altogether it's an inefficient and dangerous design. Good luck getting it to pass UL.

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  • \$\begingroup\$ This isn't a production design.. also, it's on the mains side anyway. For me, as long as it doesn't go BANG it's ok! \$\endgroup\$ – cccp3 May 17 '17 at 19:13
  • \$\begingroup\$ Besides, max. output current is ~20mA. \$\endgroup\$ – cccp3 May 17 '17 at 19:17
  • \$\begingroup\$ to me I see resonance of 4.7mH and 100uF near 250Hz and 100 ohm as a current limiter for 0.7V/100 for 7mA, not an oscillator besides UL does not care if it is used outside US with 50Hz, 230V \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 May 17 '17 at 19:40

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