On 10/21/2013 11:03 PM, Kirk Wallace wrote: > On 10/21/2013 03:00 PM, Dave Cole wrote: >> The 24 volt transformers are called commonly called Buck/Boost transformers. >> >> Oftentimes used to boost 208 to 240 volts or buck 240 down to 208.. >> >> http://en.wikipedia.org/wiki/Buck%E2%80%93boost_transformer >> >> Dave > ... snip > > Well the proof is in the putting. > http://www.wallacecompany.com/tmp/img_1475-1a.jpg > > The transformer is rated 120VAC to 12@6A or 24@3A. I wired it to buck at > 12V and got 300VDC on the Delon, which is the setup in the picture. The > AC setting on the multimeter showed 2V, so there isn't much ripple. I > also wired it to buck at 24V and got 280VDC. The VFD is a Mitsubishi > U120 240VAC 400Watt unit. It is running a coolant pump at 60Hz here. The > AC setting on the multimeter showed 2V, so there isn't much ripple. No > drama, heat or noises on any of the bits. > > For fun, I wired this setup to boost at 24V and got 420VDC, which > powered up my 440VAC VFD. I didn't run the motor because the VFD needed > programming to run from the front panel. > > So, if one has a 240VAC VFD and only a 120VAC source, this might be a > valid setup.
So you are just pumping the DC out of the voltage doubler right into the AC terminals on the drive. That goes through the bridge rectifier, charges the DC capacitors in the drive, powers the internal DC bus and you are off and running .. I like it. :-) Very simple and affordable. ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60135991&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
