Beetle Mini Power PCB

new from frogleg synthesis

The Beetle is a small PCB for a Meanwell NSD10-12D12, which takes 12VDC and generates bipolar +/- 12VDC.  It is intended to be a small power supply for standalone projects (e.g. Music From Outer Space, single/small number of modules in a mini desktop enclosure, etc).  The Meanwell can supply 420mA per rail.  If you’re interested in supplying multiple modules, you may prefer to use the Minibus (provide link here) which has 6 x 16 pin Euro headers with an integrated Meanwell supply, status LEDs and additional filtering.

documentation and BOM: beetle mania

BUILD

The Beetle has 5 parts and 2 (optionally 3) headers, so it is a very straightforward build.  Solder the diode, then the DC-DC converter, then the 3 caps, then the headers.  The 2 pin header is the input and you can output to either the 3 pin header or the 10 pin Euro header or both.  The Euro footprint expects a shrouded header, but of course if you choose to use the unshrouded type, be sure to align the red stripe with the line on the PCB.

Both MTA headers are marked with a small + on the positive side of the header.  For the 2 pin, the other side is ground, for the 3 pin the center is ground and the opposite side is -V.

Mount the Beetle on short standoffs or spacers, mount the DC jack to your enclosure, connect the tip from the DC jack to the switch (I usually plug the wart into the jack and use my meter to ensure I know which pin is tip and which is sleeve), and run wires from the other side of the switch and the sleeve of the DC jack to the Beetle using the 2 position MTA socket.  Connect the output of the Beetle to whatever your project might be and away you go….

OTHER NOTES

The BOM includes a 2.1mm input jack, power switch, and 2 and 3 position MTA sockets, as well as an appropriate 12VDC tip positive wall wart. It does not include the 10 pin Euro power header.  It is possible to use anything from a 10VDC to a 36VDC wall wart with this DC-DC converter, but note that the current required from the wall wart may vary depending on the voltage.  The recommended input would be a 12VDC Wall Wart capable of 1A to 1.5A.  A tip positive wall wart is recommended for use with the BOM listed DC jack, because the jack is metal and if you mount to a metal case, you will be tying the case to whatever the sleeve is on your wall wart.  Tip positive puts ground on the sleeve, and is consistent with the ground for the power output.  If you prefer to use a sleeve positive wall wart (say you have one already), be sure to use an insulated DC jack that won’t short the sleeve to your enclosure.

Note that the input ground and the output ground are tied together.  If your application needs a fully isolated input ground, you could cut the input header ground side and the DC-DC ground input from the ground plane and run a wire from the header to the input.  But if you use a metal enclosure and metal DC jack, you will probably still be tying the grounds together.

populated PCB:

Front & Rear scans: