M(ultiple)M(iniature)C(apacitors)


The tank capacitor is the familiar MMC style. It is constructed from strings of Cornell Dubilier caps (from the Geek Group), each one .15 mF, 2000 volts. Each layer in the picture has two separate strips of 11 caps. Each strip is thus 13.6 nF with a maximum voltage of 22000 V. The battery cable jumpers can be configured in a variety of ways to change the capacitance for other various configurations. As shown, the two strips in each layer are connected in series for 6.82 nF. The three layers are then connected in parallel for a total MMC capacitance of 20.4 nF.

The separate layers of the assembly are connected using threaded nylon rod and nylon spacers. The top and bottom pieces are HDPE, from cutting boards.


Here is a closer look at the battery cable jumper connections. These are just power cable connectors from Home Depot.


Each cap has a 10M 3500V bleeder resistor connected in parallel. All caps have plenty of spacing and connect on the ends of the strips to pieces of brass that provide a stable mount for the connectors.

Here is the MMC array positioned on the bottom deck of the coil base, jumpered for 81.8nF use with the MOT supply.