I have a photodiode/amplifier module, which has a D-sub connection for the power supply. The manufacturer sells a power supply, but it is out of my budget range, and the lab only has standard laboratory PSU's (+V,-V, gnd). Is there any connections so that I can use this module with my power supply? The DE-9 connection only uses 4 prongs (+,-,gnd, case gnd). Thanks for any suggestions.