Alan Stummer
Research Lab Technologist

Quad Single Photon Counting Module Supplies

I am curious who uses what.  Are these webpages a waste of time, or are they any help to others?  Are the circuits, software and utilities appearing in other labs?  Please send your comments or suggestions or what you have used (or not) or schematics of your version or pictures or anything!   Email me, or be creative and send a postcard! I want to hear from the vacuum! Links
  • Overview

NOTICE: This webpage and associated files is provided for reference only.  This is not a kit site!  It is a collection of my work here at the University of Toronto in the Physics department. If you are considering using any schematics, designs, or anything else from here then be warned that you had better know something of what you are about to do.  No design is guaranteed in any way, including workable schematic, board layout, HDL code, embedded software, user software, component selection, documentation, webpages, or anything.

All that said, if it says here it works then for me it worked. To make the project work may have involved undocumented additions, changes, deletions, tweaks, tunings, alterations, modifications, adjustments, waving of a wand while wearing a pointy black hat, appeals to electron deities and just plain doing whatever it takes to make the project work.


Started August 2011 for Lee Rozema and Dylan Mahler in Aephraim's lab.  This project provides the +2V, +5V and +30V supplies for the Perkin-Elmer SPCM-AQ4C quad single photon counting module.  All connections are made to the interface board .  The whole assembly is powered by a single 5V/6A external power supply.  All supplies and converters are SMPS (switch mode power supplies).  A small fan cools the SPCM.  The interface board and BNCs stick out of the back of the Bud CU-4478 case: this is a carefully calculated feature to aid in cooling by routing air through the SPCM then out the back, maybe.

+5V  This is the simplest supply, it connects to the incoming +5V.  Measured +5.115V steady state.

+2V  This is the high power supply, drawing 4Amax inrush (measured 2.5+A) with 1.5A steady state (measured 1.2A).  It is floating, a 300 Ohm isolation resisitor connecting the 2V return to the common.  The incoming 5V goes through a 5V to 5V 10W isolated converter.  The isolated 5V powers a 2V POL (point of load) converter, which in turn connects to the interface board.  Measured +1.985V steady state.

+30V  This is a low power supply.  A single 5V to ±15V isolated converter has the -15V set to common, resulting in a +30V supply.  Measured +29.85V steady state.

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