Cheap LED Alarm Light ?

[wtimothyholman]

remiss of me not to have included NVR details in my footer, I've updated this just now - it's an Dahua NVR 5216-16P 4KS2E

Okay, in looking at the user manual for the NVR (which is rather difficult to decipher due to the broken English), I think your problem may be much easier to solve than I thought. This NVR has a +12 V auxiliary power supply available at the alarm port for external peripherals. The maximum current rating is 500 mA, well above the 150 mA for the LED light that I linked to in my prior post.

So all you may really need is the LED light. Connect the positive terminal of the light to the +12 V auxiliary power terminal, then the negative terminal of the light to a normally open (NO) alarm out contact. Then connect the "C" terminal paired with the NO contact to a ground contact with another wire. The NVR will then power the LED for you.

 

[TonyR]

This has become an incredibly useful and beneficial thread for me (thanks again to all for invalable contributions) and I really do hope it also helps others too, who may have similar matters to consider. I wish I'd studied electrical engineering at school rather than chemistry or woodwork, it would have been far more useful now I'm into my mature(r) years!

@TonyRI'm not sure what a 'dry' relay contact means, but I'm guessing my NVR is solid state?

A "dry" relay output is a genuine, electro-mechanical relay output, with N.O. (Normally Open) or N.C. (Normally Closed) contacts available to the user or both available, plus a "COM" (Common) contact and there is no voltage, no pull-up or pull-down resistor to any voltage, etc.

A drawing would look like this:



I cannot say about your NVR.

 

[Chocman]

Thank you @Tony R and @wtimothyholman - I couldnt agree with you more about the difficulty in deciphering the user manual btw, it's like reading a book written by a 5 year old!

 

[wtimothyholman]

Thank you @Tony R and @wtimothyholman - I couldnt agree with you more about the difficulty in deciphering the user manual btw, it's like reading a book written by a 5 year old!

I looked at an Amcrest NVR manual hoping that their employees might have done a better job of translating the technical material. Nope, it was pretty much copied word for word from Dahua's manual. Amcrest is a perfectly reasonable company to deal with if you want Dahua-equivalent equipment with U.S. support, but it's clear that they don't do much more beyond sales and customer support. I've been told that Dahua even writes their firmware for them (no software engineers in house).

 

[Chocman]

Thanks again @wtimothyholman that is really useful to know as I've not come across Amcrest. I'm on with ordering all the bits and pieces for the Alarm out light. When it's all set up, I'll post an update of my experience/method/components so others may benefit should they wish to do similar.

 

[wtimothyholman]

Thanks again @wtimothyholman that is really useful to know as I've not come across Amcrest. I'm on with ordering all the bits and pieces for the Alarm out light. When it's all set up, I'll post an update of my experience/method/components so others may benefit should they wish to do similar.

You can start by ordering just the LED lamp that I specified. Connect it between the +12 V and ground terminals, and it should light up. If it does, all you have to do is wire it through a NO (normally open) and C (common) terminal pair, and then figure out how to trigger that terminal pair using the NVR interface.

 

[Chocman]

I've double-checked the user manual for my NVR, I'm not certain it does have a +12 V auxiliary power supply available at the alarm port, unless I've looked at the wrong unit in the manual. No problem though, your initial suggestion would work.

Dahua NVR 5216-16P 4KS2E

 

[wtimothyholman]

I've double-checked the user manual for my NVR, I'm not certain it does have a +12 V auxiliary power supply available at the alarm port, unless I've looked at the wrong unit in the manual. No problem though, your initial suggestion would work.

Dahua NVR 5216-16P 4KS2E

The user manual at

https://dahuasecurity.s3-ap-southeast-1.amazonaws.com/uploads/soft/20200424/Dahua-Network-Video-Recorder_Users-Manual_V4.5.1_2020048.pdf

indicates both a +12 V and CTRL 12 V terminal in Fig. 2-77, along with several ground connections. Of course, that doesn't mean that your particular NVR model has them. Dahua likes to publish a single manual that covers multiple models, and they often do a poor job of clarifying the differences between them.

 

[Chocman]

@wtimothyholman oh that's a totally different user manual to the one I've been reading...why don't Dahua just make things easy for their customers - a user manual per unit, simple [no reply needed on this matter ]. I'll physically check before I order the components. Honestly, you just couldn't make this up...

 

[tigerwillow1]

Fig. 2-77 is generic. Fig. 2-44 is specific to the 5216-16P-4Ks2E.

 

[wtimothyholman]

Fig. 2-77 is generic. Fig. 2-44 is specific to the 5216-16P-4Ks2E.

Thank you for pointing that out. So no 12 V port. @Chocman will need an external 12 V supply. Too bad, that would have made things a lot easier.

 

[Old Timer]

I guess you have seen the Wiki

DahuaWiki

dahuawiki.com

 

[Chocman]

No problem @wtimothyholman Easily sorted.