Den begärda sidtiteln innehåller ogiltiga tecken: "%C3".In the world of CCTV video cameras, there are a few options for power that will greatly affect your decision in the buying process. With video being integrated into many aspects of our daily lives such as phones, access control, and even mobile usage it is easy to get confused about your power source. Traditionally, CCTV cameras were 24V AC, but about 15 years ago 12V DC cameras started to become popular due to their low cost. Nowadays, dual voltage cameras have replaced 24V AC only cameras, helping to alleviate the stress of worrying about whether or not your power source is compatible to your camera. I’ll start by noting that using either of the two doesn’t affect the video transmission, only the power. You can run 1000’ of video line using either voltage easily if the camera is powered at the source. However, when using this distance for power as well, you might not be able to get the proper amount of power to your camera when using 12V DC with a camera that has a large current.

A camera’s power consumption is usually referred to in milliamps (mA) or amperage (A) if it is large enough. A camera’s consumption is generally around 200-400mA. Things like mechanical filters, infrared LEDs, and internal heaters will jump this number up considerably. Trying to power a 1.2A camera with 12V DC over a long distance is unfeasible as there will be too much total resistance in the long cable run that adds up to a substantial voltage drop resulting in camera failure. A quick test to see if you’re having problems due to voltage drops is simply to take a volt meter and measure the voltage at the camera under load (while it’s connected). A common problem attributed to voltage drop is where the camera works fine when there is low consumption but at night, when the IR LEDs turn on, it stops working completely. Problems can also include hum bars, video distortion, and other symptoms which are often mistaken as a bad camera. The solution is to go with a 24V AC camera which minimizes the voltage drop problem by using higher AC voltage.

Simply put, this entire problem of voltage drop over long cable runs is attributed to Ohm’s Law (resistance in the cable). One possible cure, as noted at the beginning, is to purchase dual voltage cameras. These cameras can be powered with either voltage by simply hooking it up to that power source. No adjustments for power or polarity are necessary as the camera itself automatically accepts whichever form you are using. You only need to consider these options when you are trying to set up a camera over 300’ and with a draw of 300mA or more.carrier window ac e4 The secondary issue to consider is the cable itself. car ac repair pearlandA low quality cable will cause a greater voltage drop and as such, will cut down the usable distance a significant amount. 2001 honda civic ex ac compressor clutch

Even within 150’ or less you can find a problem getting power to a camera using 12V DC if the cable is of poor quality. The braid count for CCTV cable makes a large difference in impedance and often cables that look the same may not perform the same if one is better shielded than the other. Keeping all of this in mind, it is clear to see that you will want to use AC power whenever you have a long distance to travel or if you are using a smaller diameter wire that may not allow your 12V DC camera to get the proper current it needs to work. Also remember that in the U.S. the wire gauge number represents a larger piece of wire as the gauge number decreases. The easiest and best solution is to look for dual voltage cameras so you no longer have to worry about it. Please note that nowhere in this discussion have we been referring to video. Video problems over long hauls and how to solve these issues will be discussed in a future article. are original works and copyrighted by PolarisUSA Video, Inc. Site scraping or other illegal usage is strictly forbidden, and any sites found with unauthorized duplication will be issued a DMCA takedown notice.

Rating: 79%   (101 votes) Please help us improve by rating and sharing our content! Was this article helpful?      The most obvious difference between AC cooling fans and DC cooling fans is the type of electricity that they use. DC cooling fans use direct current (DC) electrical flows. This type of electrical flow can only move in one direction. AC cooling fans, however, use alternating current (AC) charges that can change direction quickly. The use of DC or AC current might seem insignificant, but it can produce very different results. There are, therefore, specific uses for AC and DC cooling fans. Voltage of AC and DC Cooling Fans In general, AC cooling fans have motors that use higher voltage than DC cooling fans, so the AC models are often used to produce high pressure air currents in systems that will not malfunction because of the fan’s electromagnetic interference. Most DC cooling fans operate at low voltage. You can generally find 5V, 12V and 24V versions;

and in larger sizes, from 119mm to 172mm, in 48V. In comparison, 115V is one of the most common AC cooling fan models. Uses of AC and DC Cooling Fans All types of computer equipment rely on DC cooling fans to prevent them from overheating. This includes everything from large servers to home PCs. The advantage of DC cooling fans is that they create less electromagnetic interference. This enables them to cool computer systems without disturbing processes with electromagnetic interference. When choosing DC cooling fans for your computer, you might find that some of them are rated as 48VDC instead of 5V, 12V, or 24V. This is perfectly normal. VCD is simply another way of stating the amount of voltage that the fan uses. While the DC and VCD differentiation makes no difference, you should be certain to choose brushless models for your computer cooling needs. Installing AC and DC Cooling Fans Always use caution when installing AC or DC cooling fans. It is best to make sure that any equipment is unplugged before attempting to install fans.

Both DC and AC currents can cause serious damage to humans when delivered in powerful doses. Even though most modern home electrical systems will not deliver a deadly jolt, a slight slip could still cause significant pain or even tissue damage. Choosing AC and DC Cooling Fans Before buying AC or DC cooling fans for your home’s temperature control system, home entertainment center, or computers, you should conduct some research to make sure that you choose an effective model. The differences between AC and DC cooling fans are significant to many machines, as is the differences between the voltages that they use. Most manufacturers include information about the types of fans that consumers should use in their products. If you cannot find this information, then try to replace the existing fan with a comparable model. Other AC / DC Cooling Fan Articles What are AC Axial fans? What are DC Axial fans? What is an AC Cooling fan? The functionality of AC Cooling fans?