Good MMC Capacitors

good mmc capacitors tesla coil induction heater

Published December 26, 2013. Updated February 24, 2021.

Here is a list of capacitors tested by the high voltage community to be known to withhold the use as primary capacitor in Tesla coils.

Capacitor specifications are taken from data sheets at 100 kHz and some values for peak current, RMS current, ESR and dv/dt are estimates(* marked) from similar capacitors and graph read outs.

Product  IpeakIrmsESRdV/dTRth
data sheetVμFAAV/μS°C/W
Aerovox RBPS20591KR6G1000285422742715*
Kemet Arcotronics
C4DRPAQ4500AA0J
120051600641.13203.3
CDE
942C20P15K-F
20000.1543213.55287911
CDE
940C20P1K-F
20000.11718.37171211
EFD SP
2550-2
10003.752500*1521810*10*
Kemet
R474N247000A1K
9000.047284*13560051
Kemet
R76UR3150SE30K
20000.153451026230023
Panasonic
ECWH16333
16000.0331983.5350*600040
Panasonic
ECWH16473
16000.0472824.3250*600040
Panasonic
ECWH16563
16000.0563335150*600040
TPC
CMPPX4K0K0405
30004500080*0.7512506.9
WIMA
FKP1O131007C00
10000.111006101100033
WIMA
FKP1T031007E00
16000.111006101100033
WIMA
FKP1R032207F00
12500.222420691100033

Capacitive reactance Xc = 1 / ( 2 * π * f * C)

ESR can be calculated from the tangent of loss angle given as TANδ in the data sheets. ESR is frequency dependant. Capacitance is given in Farad, frequency in Hertz. ESR = (1 / (2 * π * f * C)) * TANδ = TANδ * Xc.

Thermal resistance (Rth) when given in data sheets are either Watt needed to raise the temperature by one Kelvin or degree Celsius the temperature raises by one Watt dissipation. Conversion from W/K to °C/W is to divide one by W/K dissipation factor.  °C/W = 1 / (W/K).

Ipeak is calculated from the dV/dT rating times the capacitance of the capacitor. Capacitance given in micro Farad times pulse rise time given in micro seconds will give a result in Ampere. Ipeak or Ipulse = C * dV/dT.

As a rule of thumb ESL is about 1.6 nH per millimeter of lead distance between the capacitor itself and the rest of the circuit. This also includes the leads of the capacitor itself. This only applies to well designed capacitors.

One thought on “Good MMC Capacitors

Leave a Reply

Your email address will not be published. Required fields are marked *