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Another power supply! (DSP-45 switcher)

posted Feb 19, 2017, 7:52 PM by Charles Boling
DuraComm DPS-45 12VDC switching power supply

My Civil Air Patrol wing upgraded my home radio station, replacing my Motorola Micom 2 with a Micom 3F. The new radio has a nicer display, does ALE, etc. They were also kind enough to send me home with a new power supply, since they'd really like me to keep my radio on full-time so I can be paged over HF.  The new unit is a 45-amp switching supply.

It's normally fixed-voltage, but has a jack that you can insert a shorting plug to cause it to bump up the voltage roughly .5V to quick-charge.  Better yet, there is a module you can get that turns it into a 4-stage battery charge maintainer.  I looked online. and saw them for $65+ plus shipping.  However, I also made another discovery: the DPS series of power supplies (and the IQ-4 controller) is actually made for DuraComm by Iota Engineering, and is identical to their DLS series (which seems to be marketed more to RV'ers -- which also tend to get ripped off, but not nearly as badly as telecomm pros do...) -- I call it a power supply; my father-in-law would call it a "converter"). I was able to find an
Iota brand module for $17 shipped. I also dropped the float voltage on the supply (it has a trimpot that's covered by a sticker) from 13.8V to 13.4V since I'm using a conventional flooded battery and not gel or AGM.  The weekly anti-sulfation cycle doesn't go as high as I might prefer, but it's close enough.

I do like that supply!  Solid regulation (very low ripple, dip of only .1V @ 30A draw), low RFI, efficient & cool/quiet -- I beat it up pretty good last week doing net control, and the PWM fan never even needed to kick in.  Plus, it has built-in current backflow protection, eliminating the need for an external diode!  I installed in in the cavity where the big PS-36KX assembly was sitting, and freed up a whole lot of space, plus have a cooler quieter supply for the 12V radio stack.

The price on these is actually quite reasonable, too -- cheaper than a [decent] equivalent supply marketed to hams, and has built-in battery maintenance.  Good enough!