Feb 18

Written by:
2/18/2009 1:28 PM 

As mentioned earlier in this post, I'm currently working on bringing a vintage Buchla 200 system back to life. A few weeks ago I started to design the cabinet and after a few twists and turns the cabinet was finally finished last week.

During the last couple of days I've been working quite hard to mount the modules in the cabinet and test them. The biggest issue I've had so far is the original Buchla power-supply, which was connected through an old step-down transformer. As a precaution I briefly measured the voltage between the power-supply chassis and ground before connecting any of the Buchla modules to it. To my surprise I discovered that the voltage between the power-supply chassis and ground was approximately 230V! Disassembling the step-down transformer revealed that it was and old autotransformer. An autotransformer is an electrical transformer with only one winding. Since the input of the transformer isn't electrically isolated from the output its output may result in 230V between neutral and ground if the power plug happens to be plugged into the outlet the wrong way around.

I'm VERY keen on electrical safety issues so I will replace the old autotransformer with an isolated step-down transformer and rewire it according to modern standards. Hopefully I'll get the Buchla-system up and running in a day or two so I finally can test it!

Copyright ©2010 Niklas Eriksson