E_Notes : Page #1.00
A collection of notes that I am collecting usually relating to audio or electronics.   Comments are wellcome.

Also found on the fabrication page.
These are screen captures of some of 6 pages of notes I put together to put some kind of handle
on filament current and the potential hum from the flux.
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Hi,
This is my first attempt at a web site.  So things,  
will no doubt be, dynamic for a while. Change is
the only constant.
admin@testvector.com
Listed below are some notes I have collected including :

Hum
        I wonder from, where it Come ?
Joule      1/100 of one droplet of beer.
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WMF of schematic above.  

Above is the schematic of a TDK KU-33394V-OT
DC-DC Converter.   

This version creates 3 negative DC supply
voltages, -10V, -15V, -20V,  plus a center taped
secondary.   

The schematic shows a modification I did to get
+/-15v DC.    
I purchased these little supplies at :
http://www.allelectronics.com/cgi-bin/item/DC-32/search/DC-DC_CONVERTER_.html
First 25 at 2 for a buck then 200 more for $0.25 each.  Hard to find  raw transformers
for a quarter each.

These are conventional mode high frequency, (about 120kHz), DC to AC to DC
power supplies.   The transformers work in pulse mode.  I hooked a PWM controller
and MOS switch to  one of the transformers and got several hundred volts pk-pk.
Ground Loop / Looping
For a single ended supply :
Input is the difference between, Vref and Source.
Vref can ride on top of Vg.  In this case Vg is proportional to the signal in that part of the circuit.

The effect of Vg on Vref is basically masked in this case.
In this case Vg of unrelated circuit stages can cause voltage drops across
other module's ground path resistances.  

Thus modulating the Vref with the voltage drop of the unrelated signal.

Modulating ground is the same as modulating the signal in the context of single ended designs.
Ground or Vref Modulation



admin@testvector.com
k-leyva@pacbell.net
Notes :

Hum
TDK DC-32
Ground Loops