Letter Re: DC to DC Converters

Hi Jim and Readers,
Some of our TEOTWAWKI preparations tend to lean toward running electronic equipment off charged DC battery sources. I work in electronics, and have built several radio stations for ministries around the world, I have found that DC to AC inverters especially the cheaper models are very inefficient to run higher powered equipment. I have gone another direction when powering equipment off of 12 or 24 volt DC power systems. Many people will purchase a DC to AC inverter to run a laptop through the supplied AC to DC converter. The newer switching supplies are very compact and efficient, but when you convert from DC to AC the efficiency goes down. So why not convert once, from DC to DC?

I have found a company that sells high end DC to DC converters. The Avel Lindberg Company makes very good shielded and moisture resistant units. Their primary market is the military, I have bought units used for certain weapons systems, that are fairly well hardened for EMI / EMP. I have used them up to 300 watts and they work very well with no maintenance for long periods of time. I also have converted equipment like some of the small microphone and media mixers from the AC to DC converters that are supplied with the equipment to straight 12 Volts DC by removing the plus minus supply internally and the AC to DC converters and installing DC to DC converters directly inside the units. The devices can be purchased from Internet/catalog electronic parts dealers like Mouser, Allied Electronics, and Newark. All of the above companies can be found with a search engine to get access to their on-line catalogs.

The first thing to remember when converting something from one source to the other is to check the supplied power cube for the output voltage and current rating. Then order the correct DC to DC converter for the voltage and current rating needed for your electronic equipment.

What I usually do is obtain Anderson Power Pole connectors before cutting the power cable be sure to check with a digital volt meter or older volt ohm meter, the polarity of the power plug of the supplied power cube. I then remove the cube from the AC electrical source. Unplug it. Then cut the cable about a foot or two from the units connector. Install the Power Pole connectors on both ends of the cut cable that are left, insuring you set up the red positive, and black negative connectors correctly.

Now take your DC to DC converter and install the appropriate red positive and black negative connectors on it. Connecting the DC to DC Converter to the appropriate 12 or 24 volt DC power source and check your output when the pigtail connector with the power pole with your meter again insure the voltage required and polarity are correct. If it checks out correctly then plug it into your electronic device and energize the device. The input source voltage to many DC to DC converter will accept from 8 to 30 volts DC so it will be more versatile than the original power cube.

Two of the benefits of making conversions like this will cut out the AC inverters from the equation and the other is reducing the current drain a little bit on your battery capacity.
I realize there are many people who would feel deliberately cutting a wire would be fool hardy if they are not competent in electronics, or electrical devices . This can be overwhelming to someone, so if you feel performing this kind of modification is beyond your competency level please seek out someone who is competent. Performing a modification like this is simple to some, but don’t do it if you feel it is beyond your capability. Blessings to all, – Dave with Martronics