[sdiy] connectors for power distribution

[Rob Keeble]

Hi
I agree with Seb, put +5V supply (78X05's) for CMOS/TTL/etc on the PCB
modules. It provides better isolation and reduces the number of power lines.
For VCO's I now put local stable voltages of +5 and +/-10V on the PCB using
ultra precision voltage references (0.6ppm devices). Its very important to
have a high quality power supply for VCO's....drift in the supply translates
directly into drift in frequency. The main power supply(s) just provides a
+/-15V bus to all modules (usually at 1mV drift from LM723 based PSU).

I also separate out power on the PCB for LED's and LED driver Op Amps and
decouple them separately from audio as per Sebs email. Decoupling electro
caps are 47 or 100uF for these jobs.

I have also switched to using high quality Panansonic FC range electro
capacitors (22uF and 100uF)and axial multilayer ceramics (100nF) for
decoupling the main power onto the PCB, with inductors as per Sebs email.

I use the "standard" 4-pin 0.156" MTA (MOTM style) power connectors for PCB
connection, in case any customers buy the PCB/module. These connect to
distribution PCB's which are powered by regulator PCB's mounted in the
cabinets. These are fed from 16-20VAC power via 3-pin Bulgin connectors from
a remote metal box with power transformers and final 240VAC input.

My CV and gates signals go in and out via 8pin circular connectors (not DIN
to avoid confusion with MIDI !).

Regards
Rob


Here we go: What do you people think, is it better to use local
regulation for 5VDC digital stuff in the modules or going to concept
of having +5VDC distributed too? (with separated digital or "dirty"
ground, only connected in the PSU)

Samppa