Friday, January 15, 2016

The Variac That Took Us To The Moon

I generally don't have much work around the Christmas holidays going into the first few weeks of the New Year.  I hate not have much work, but there is an upside.  I have time to repair gear, and time for new work projects.

Here is one of my projects; a 20 amp variac.

This is an old General Radio type W20 that is in perfect condition.  It came from an old 3-phase lab bench type variac; cool but not suitable for use on a set.  I've had the parts for it sitting around on a shelf for the past couple of years.  I just hadn't found time to work on it until now.  I love old electric devices like these.  The design is simple and brilliant.  The construction is top-notch.  These were designed to exceed their rated capacities and last a long time.

One of the hardest parts in turning this into a studio-use variac is just finding an enclosure that it will fit.  Then there is a lot of cutting and drilling, before the variac can be put into the enclosure.

On the bottom of this variac is a super-cool old ID label from NASA.  This could be the variac that took us to the Moon.  Maybe.  Anything is possible.

Not having the original insulated shaft for rotating the brush assemble, I substituted an acrylic rod.  This assemble is energized when the variac is on.

Here is the finished "Moon" variac complete with it's original ID plate.  I have added a breaker and a power-on indicator light.  I also like to use indicator plugs.  These are very handy allowing you to see at a glance if there is power to whatever you are using.

This "new" 20-amp variac will be a nice addition to my gear.   Now I have 1-7.5 amp variac, 2-10 amp variacs, 2-20 amp variacs, and 1-50 amp variac.
Here is my largest variac, a 50-amp beast!  The unistrut cage is to protect the variac.  Variacs look indestructible, but actually are fragile.  They need to be handled carefully.  One drop, or an impact to the coil, could irreparably damage it.