It is a Beta Circuit, and still under development, but follows on from working models.

It has been designed with 12V accumulators (batteries) in mind, but could be modified for higher voltages if needed.

The circuit is of the N Channel Mosfet type, as low "On" impedance "P" Channel types are hard to come by and can be expensive! The Mosfet used is a International Rectifier, IRF 2807, rated at .013 On res, 82 A, at 75 V, and should cost only around $4 ( In the Diagram, its called irfz 44v just for placement and package info) The Diode, D2, is a RHRP 3060, Hyperfast TO220 pack, rated at 30Acont, 500v, 325 Apk, and should cost around $2

1) There are a few additional components added, in line with the High Power version, made by Alastair Couper, These are, DE1, D3, and RE1. I added these as an option in the finished layout, to be flexable to experiment, but can be omitted if needed, although, you need to bridge RE1, if you do. ( RE1 should be left in, to dissipate the Gate Charge however.)

2) Extra pulse protection has been afforded to U1, by L3, CE2, and CE1. Strange behavior can happen if pulses of too high an amplitude are present on U1 rails. D1, has been set to 14V, to prevent overload of U1, when used with larger chargers

The Layout.

It is of a double sided type, with most of the tracks duplicated, to improve current ratings. ( If needed for very high current pulses, you can place additional copper braid along the high current paths near the diode and Inductors to further lower the resistance, to which these circuits are quite sensitive!)

There is provision for two caps for C4, to reduce ESR and heating effects, and as others have recommended, should be 100V rated, and have a low ESR, Panasonic FC series caps are good here.

There is also provision for two Diodes, D2, also to improve current ratings.

The Inductors, L1, and L2, I am to use are made by Pulse Technologies, and are intended for the "Simple Switcher" Voltage Regulaters by National Semiconductor. Current ratings are, L1, .94 A@ 1000uH, and L2, 1.4 A,@ 220uH. Both are Toroidal.

There is sufficient room and pad size to accomodate different chokes if needed, Just drill to suit your chokes!

An LED, has been included, to indicate unit operating, It will not light if no pulses present. Its series Resistor, is a surface mount type, but any small one soldered to the pads will do!

I have also used a surface mount cap for CE1, basically, to place it as close to the power pins of U1 as possible, but any .1uF small cap can be used here