What is it?

This board is a ±12 and +5 volt power supply. It is intended to power the Thunderbolt GPS disciplined oscillator. It can supply +12V @ 800 mA, +5V @ 500 mA and -12V @ 50 mA from a 15W 13.8-15 VDC input.

The +5 and -12 supplies are hybrid switcher + LDO designs. The switching supplies yield good efficiency while the LDOs adds ripple and noise rejection. The -12V switcher is based on the MC34063 and the +5V switcher is based on the AP1509. The +12 output uses an LDO fed directly from the input. Typical noise and ripple on each output is less than 10 mV P-P.

The output is a standard 4 pin .1" SIP header, which is included. Wiring and connectors beyond that are not included. The board can be screwed into an enclosure with #4-40 hardware. The mounting holes are electrically grounded.

The optional AC power supply supplies 15W @ 15VDC from 90-264 VAC, 50/60 Hz. The input jack is a standard 2.1mm barrel connector, center-positive.

Why did you make it?

The Thunderbolt GPSDO requires relatively low noise power input, particularly on the -12 volt input. I decided to design something smaller and less noisy than the surplus laptop power supply I had been using.

What makes it special?

While it was designed for the Thunderbolt, it's useful for any application that requires relatively low noise ±12 and +5 volt power.