I built a simple, direct-coupled mains power supply.
I wish to get on my load about 6V and 20mA DC. My mains is 220V AC.
I used a 1uf 250V capacitor, a bridge, a resistor, and two 100uF tantalum capacitors.
The 1uf /250V capacitor (NP) works well, and I got about 7VDC. However, I need a conderably smaller physical size capacitor.
I "built" a capacitor made of several 1uf/50V capacitors in series and parallel, so I got 1uf / 250V. Connecting it, the output was only 4.2V.
The caps temperature was about 45 degrees Celsius.
I replaced the 30(!) capacitors with 3 capacitors X 3uF / 100V in series. The temperature increased to approx 100*C! The voltage on the load also increased to 7.2 V DC.
I tested the capacitors, I replaced them with 3 new ones - but they are warming to more than 100*C.
Can someone suggest what happens? Why the 50V capacitors barely warm, and the 100V are warming as hell?
Thank you in advance for helping.
I wish to get on my load about 6V and 20mA DC. My mains is 220V AC.
I used a 1uf 250V capacitor, a bridge, a resistor, and two 100uF tantalum capacitors.
The 1uf /250V capacitor (NP) works well, and I got about 7VDC. However, I need a conderably smaller physical size capacitor.
I "built" a capacitor made of several 1uf/50V capacitors in series and parallel, so I got 1uf / 250V. Connecting it, the output was only 4.2V.
The caps temperature was about 45 degrees Celsius.
I replaced the 30(!) capacitors with 3 capacitors X 3uF / 100V in series. The temperature increased to approx 100*C! The voltage on the load also increased to 7.2 V DC.
I tested the capacitors, I replaced them with 3 new ones - but they are warming to more than 100*C.
Can someone suggest what happens? Why the 50V capacitors barely warm, and the 100V are warming as hell?
Thank you in advance for helping.