I cannot tell you what the minimum power supply voltage requirement for your older professional video camera or portable HMI light ballast is, however voltages lower than 12 volts can sometimes do damage to either one in a relatively short time.

Please don't confuse this guide for electronic equipment that runs on less than 12 volts DC such as 7.5 volt or 6 volt DC devices, or devices that use much higher voltages than 12.0 volts such as 18, 24, or 30 volt devices.

Beware of 4 pin AC to DC power supplies that have a maximum power supply output of 12.0 volts DC. By the time you plug in a 12 volt unregulated power supply into a wall socket in anytown U.S.A. and factor in a 6 to 12 foot, 4 pin power cable, you may be supplying your video camera or HMI lighting ballast with less than 12 volts. Voltages lower than 12 volts can sometimes slowly burn out certain components in your older video camera or HMI lighting ballast. Voltages of under 12 volts are what I call the equivalent to a "slow motion" voltage brown out that might slowly destroy key electronic components in your older E.N.G. Video Camera or portable HMI light ballast.

Supplying proper voltage to your professional, older style E.N.G. style camera or Portable HMI light ballast is essential to ensuring you don't damage the electronics of either. Unregulated and Regulated Power supplies that output a maximum of 12.0 volts may not be the ideal power source when compared to a regulated power supply that outputs a robust 13.2 to 13.8 volts. Voltage Brown outs can do just as much damage over time to your video camera or HMI lighting ballast as too high of a voltage can do. You could be inadvertently browning out your video equipment if you feed it too low of a voltage for too long of a time. Older Professional Video cameras along with portable HMI light ballasts are supposed to shut off when the supplied DC voltage gets too low. The low voltage auto shut-off system seems to work fine if you are using a battery to run your E.N.G. Video Camera or HMI light ballast because a battery will continue dropping it's voltage output as it naturally runs down until the video camera or HMI light automatically shut offs. However a power supply can run all day at a voltage that is just high enough to keep the camera or HMI light on, but is actually of a low enough voltage to do harm to your Older Video Camera or HMI light.

A battery's voltage output might drop to as low as 10.6 volts before a professional video camera or HMI light ballast automatically turns off. However a battery usually won't be able to power a video camera or HMI lighting ballast for more than a few minutes to a half an hour at such a low voltage before automatic shut-off occurs. A short time at a lower voltage before automatic shutoff occurs is probably not as bad as a power supply that continually is outputting under 12 volts for hours on end. Anton Bauer digital batteries output at 13.2 volts instead of 12.0 volts, however, when freshly charged those same batteries can output as high 15.5 volts for the first part of the run cycle. As the battery runs down it will slowly drop to 13.2 volts. Internal battery shut-off should occur soon after. Many video cameras can handle between 11 volts on the low side and between 15-16 volts on the high side. If an accepted range of 11 volts to 15 to 16 volts exists, then clearly running an older video camera at under 12 volts is on the low side of the voltage range.

An unregulated 12.0 Volt AC to DC POWER SUPPLY MAY NOT PROVIDE ENOUGH VOLTAGE for older professional electronic equipment that use 4 pin power cables and need a MINIMUM of 12.0 volts to operate properly. When you factor in that the wall socket outlets may only be outputting 110-115 volts instead of 120 volts and that your 6-10 foot 4 pin cable run can cause an additional voltage drop of .10 to .25 volts you have a recipe for a slow brown out disaster to occur in which your video camera or lighting ballast may only be receiving around 11.0-11.5 volts for extended periods of time. Not all video or HMI lighting equipment will react poorly to voltage that is slightly under 12.0 volts, but the older the gear, the more likely that a problem will occur at voltages that are continuously under 12.0 volts. Ideally, regulated 13.2 to 13.8 volts and 6 to 10 amps output can help prevent brown out damage from occuring to your older video camera or portable HMI light ballast.

Caution, although I don't know what the actual High Voltage threshold is an older video camera or portable HMI light ballast I have heard that most cameras should be able to handle up to 15 volts, perhaps even a bit more, but that is just what I have heard and cannot verify that for certain.

Regulated Power supplies are supposed to sustain the stated specified voltage output even if the wall output voltage slightly drops, however your overall amperage output may drop when AC voltage drops below 120 volts. The lower amperage output compensates for the regulated power supply maintaining it's promised minimum voltage. Lower amperage is not necessarily a bad thing as long as it is still higher than the amount your equipment needs to run properly. However, even a regulated power supply will probably have a slight drop in voltage output depending on the length of the 4 pin XLR cable, the longer the cable, the more voltage drop off there will be. I have heard of voltage sensors being built into the power supply that actually compensate for the line voltage drop but I don't know how common these types of power supplies are.

What is the lowest voltage power supply I would use for older electronic video camera that requires 12 volts to operate? I can't say for sure, ideally I would like to start with a 13.2 to 13.8 Regulated AC to DC power supply. However you could probably make do with a Regulated AC to DC power supply that outputs in the high 12 volt range such as 12.8 volts. A power supply with an unregulated maximum voltage output of lower than 12.8 volts and it might just be a matter of time before you encounter a situation where the length of the 4 pin cable run to the camera or HMI lighting ballast combined with slightly lower voltage coming out of the wall socket can lead to voltage levels of less than 12 volts and an increased possibility of burning out key components inside your older professional video camera or HMI light ballast.

What if you already own a 4 pin, 12 volt AC to DC power supply? There is one use that I can think of that should not cause a problem and that is to power 12 volt tungsten lights. Unregulated 4 pin, 12 volt power supplies may not produce the same voltage output whenever you change locations which can cause the tungsten color temperature to vary from day to day and location to location. Lower voltage output will actually cause the light to output a more saturated warmer color from the lower end of the color temperature scale which can be a problem if you are trying to match color temperature of the lights over a certain time-span. A REGULATED power supply should better help ensure that the color temperature matches better overall. Another potential downside to having a power supply around that tends to output in the low 12 volt range is that it probably is just a matter of time before a situation arises in which the power supply will end up powering up either an older video camera or portable HMI lighting ballast. Space becomes an issue when preparing for a film or video shoot so my preference would be that any power supply that is in my kit be useable on ALL of my 4 pin gear and not limited to just one use.

Well, I just got my first negative score (Oct. 18, 1007) for this guide, was it from one of the very few power supply manfacturers who didn't research the 4 pin XLR power supply market before making their product available for sale? If the 12 volt power supply manfacturers disagree with my findings that a minimum of 13 volt output is necessary for older E.N.G. video cameras and portable HMI light ballasts, make a rebuttal eBay guide rather than just giving me an anonymous negative score. Or you can spend less time being concerned about my words of truth and spend some time improving your product for your customers sake.

Contact me if you believe I haven't considered something before giving me a negative score. I have carefully researched this situation and speak from my own experience. I own four of the 12 volt maximum XLR power supplies purchased here on eBay and after they damaged TWO of my portable HMI ballasts in the same weekend I realized I could not use them anymore. I also won't give them away for free because I don't want to see someone else mistakenly hook them up to the specific types of equipment I mentioned in this guide, older E.N.G. video cameras and HMI lights with portable ballasts. If the rest of you appreciate the information I have provided above, information that I myself follow, please consider giving this guide a positive vote as it appears to be under regular attack by those who would rather sell the wrong kind of 4-pin XLR power supply to unsuspecting eBay bidders.