cglaeser

I can't find a description of the implementation for the VR series. Given that the VR1 through VR5 series are packaged in a relatively small plastic box without a large exposed heat sink, is it likely that they are the more efficient switching regulators? The VR4T converts 24VDC to 12VDC @ 3A. Wouldn't a linear regulator require a relatively large exposed heat sink? See http://www.altronix.com/index.php?pid=2&model_num=VR4T Best, Christopher

Another question about voltage regulators. The AL624 has jumpers to select the output voltage of 6VDC, 12VDC, or 24VDC. The suggested input voltages are the following: 12VAC input for 6VDC output 16.5VAC input for 12VDC output 24VAC input for 24VDC output Given that 24VAC is already available, rather than use a 16.5VAC wall wart, is it OK to use 24VAC input for 12VDC output? Do voltage regulators dump the excess voltage as heat? Will using 24VAC produce more heat than 16.5VAC when the output is 12VDC? Specifications are at http://www.altronix.com/p_pdf/AL624.pdf Best, Christopher Edit: Wiki is my friend: Unlike a linear power supply, the pass transistor of a switching mode supply switches very quickly (typically between 50 kHz and 1 MHz) between full-on and full-off states, which minimizes wasted energy. Voltage regulation is provided by varying the ratio of on to off time. In contrast, a linear power supply must dissipate the excess voltage to regulate the output. This higher efficiency is the chief advantage of a switch-mode power supply.

+1.

Good point. Optex and Crow make excellent outdoor PIRs. I am currently using the Optex Redwall SIP-100 to monitor a footpath that is 100 meters from my house. That PIR is an incredible performer, rain or shine. I have not yet used the Crow D&D, but it too receives excellent reviews. Thanks, will do. Best, Christopher

Very modest current at 8.4mA per PIR. Which one is the linear reg? The AL624? Yes, I think they are isolated relays. Thanks for the assistance. Best, Christopher

Yep, I hear ya. The only thing I would worry about is people. If camera or other equipment is mounted high enough to pull a strike, need to make sure the strike is grounded to avoid injury. But as you know, that still won't save the camera. Best, Christopher

Keep in mind that a surge protector protects equipment from strikes coming over the grid. If lightning directly strikes the camera ... poof!!!! Best, Christopher

You will see the fog, smog, and smoke, similar to the visible spectrum. Thermal cameras can see heat through fog, smog, and smoke. See http://www.youtube.com/watch?v=uz0Ee8hFudY Best, Christopher

CAI Networks sell an inexpensive Ethernet I/O device called WebController. See http://www.redhillnetworks.com/products/webcontrol/webcontrol-faq.html The device requires 6 to 9 VDC. The device would be easier to deploy if it used PoE for power. I called the company yesterday and suggested they add PoE in a future rev, and he appreciated the feedback, but indicated that using PoE was not really a good option for them. I don't think he had considered PoE before, so perhaps he was shooting from the hip. What are the design considerations when converting 44 VDC to, say, 5 VDC in a PoE application? In particular, what is the part cost, and what is the efficiency? Are there evaluation breadboards available? Is it possible to easily add PoE to power an existing non-PoE device? Best, Christopher

Thanks, this is helpful, and echos the comments of the CAI designer. He said that using a) the more common 7812 type of approach would produce too much heat and insufficient power, and b) he also did not want to use a switching approach due to reliability. Comment a) makes perfect sense. I don't know if the approach in b) is less reliable, but he is confident in the reliability of his existing design of regulating an input with lower voltage and higher current. Best, Christopher

I have a 207MW. These cameras are solid performers. Best, Christopher

This is my understanding of the conversation. I don't think he was questioning the reliability of all regulators, and I believe they use them in their designs. I think he was comparing the reliability of regulators that reduce the voltage by a modest margin versus those that reduce the voltage by a factor of eight and increase the current by a factor of six (my words, not his, but that was my understanding). Is there a difference in reliability of regulating a 7.5V@2A to 5V@2A versus a PoE splitter converting 44V@0.3A to 5V@2A? Best, Christopher

Right, it's roughly a third of an amp at 44v. Some splitters deliver 10W at various voltages (e.g. 2A @ 5V). According to the tech at CAI, he was concerned about the reliability of low-cost dc-dc power devices. FWIW. Best, Christopher

Given that fiberglass ladders are typically heavier and more expensive than aluminum ladders, why do you suppose installers bother to purchase them? Best, Christopher

Thanks!!! - Christopher

Isn't getting advice on how to do a stadium install from someone who has actually done a stadium install sort of like, um, cheating? Best, Christopher

Is there a wiring standard for 12 VDC power plugs? Should the outside conductor be plus, minus, or there is no standard and could be either? See http://www.amazon.com/2-1mm-5-5mm-Female-Power-Adapter/dp/B003MHUN7S/ref=sr_1_2?tag=gpse-20&ie=UTF8&qid=1292217153&sr=8-2 Best, Christopher

Oops, my bad. I knew that. Been reviewing to many camera specs. Do you have a link to the Avigilon enclosure for the H.264 box. I did not look today, but I looked a couple weeks ago and could only find a part number, but not the enclosure product page with dimensions or picture, etc. Would not need a heater in this environment. Best, Christopher Edit: Would prefer the smallest enclosure that will hold it.

Excellent. Which lens did you select for the box camera? Best, Christopher

Are you still on track to receive your Avigilon test camera next week? Best, Christopher

The OP did not mention the intent of the surveillance, but if the intent is to catch someone who hopped the fence and entered the premises, I would rather have two or three $150 cameras with iPhone viewer and put the rest of budget towards PIR and/or perimeter IR beams that would text me when someone hopped the fence. If you call the police while they are on the premises, and you can tell the dispatcher that you see them right now, you have a much higher probability of catching them than giving the police 2 MP images taken with $1,000 cameras hours after they are gone. Best, Christopher

Is that an aluminum ladder in the first photo? Best, Christopher

The CNB MIR3000 has an EXT / AUTO switch that configures the illuminator to turn on/off based on an external control or a dusk-to-dawn light detector. The switch is located inside the head assembly, and the head assembly is attached securely with several screws. There is a sticker on the head assembly that says, "DO NOT OPEN". How do you toggle the switch between EXT / AUTO without opening it? Best, Christopher

Does the CNB MIR3000 IR Illuminator come with 12V power supply? The supplier installation drawing shows a power supply, but I don't know if it is included. I placed an order for an MIR3000 and it should arrive next week, but I don't know if I need to place an order for a 12VDC regulator. Best, Christopher

The CNB MIR3000 does indeed include the power supply. Best, Christopher