So thought I would post small video of my second output working with mosfet and relay, seeing don't have studio just used my cluttered and messy desk, don't judge lol. Wanted to show webui along with desk of the circuit while I control both outputs one going to small draw amber led block and two going through mosfet and 12v relay with external 12v power supply, running a load of 1.84amps
https://youtu.be/WfpGyNtpUXc?si=xtBvHspfPlgSNjWr
NV4232E-16P-EI Alarm Block Pinout
Re: NV4232E-16P-EI Alarm Block Pinout
No I am using a Mosfet and a resistor, The mosfet will turn on with the 12v that changes when the port is active alarm and will end when CTRL becomes 12v. This is able to work because the Mosfet don't take much current to turn on and produces enough current to drive a relay and even more. There are many different ones. In fact if I was willing I could OMIT the relay and drive direct from the mosfet but want to use the Contact of a relay as a way to protect the Amcrest NVR.. I posted detailed info on my Forum and can be found here.. https://www.revo2maxx.info/viewtopic.php?t=404
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Re: NV4232E-16P-EI Alarm Block Pinout
Personally I wouldn't use a Zener diode, I mean I am not sure how you are trying to use it as Zener diodes are unique, Zener diodes are commonly used in voltage regulation, over-voltage protection, and reference voltage applications. They have a Forward and Reverse Bias and if not installed in a circuit correctly could damage what you might be trying to protect..
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Re: NV4232E-16P-EI Alarm Block Pinout
Using a Zener diode with the NVR's output and a 12V power supply in place of a MOSFET can be problematic, and the MOSFET setup is a much more reliable and efficient solution for several reasons.
Why a Zener Diode Setup Can Be Problematic:
Power Dissipation:
Zener diodes are typically used for voltage regulation or clamping purposes, but they are not ideal for switching large loads like relays or for handling higher currents. Zener diodes are meant to maintain a specific voltage across them, but they will dissipate power and generate heat when conducting, which can become inefficient, especially with inductive loads like relays.
Current Handling:
Zener diodes are not designed to carry significant amounts of current. Relays, especially ones that require higher currents (e.g., 200mA or more), could potentially damage a Zener diode that isn't rated for such currents. Even if the Zener is rated for higher current, the setup would likely be inefficient compared to a MOSFET.
Voltage Regulation Only:
A Zener diode alone would not switch the relay on and off effectively. It would regulate voltage at a certain threshold (e.g., 12V), but that doesn’t provide proper control like a MOSFET, which can act as a switch to fully allow or block current flow. You’d have less control over when the relay is activated or deactivated.
Complexity of Proper Biasing:
Using a Zener diode would require a more complex circuit design to ensure proper biasing and control. You would likely still need to add a transistor or MOSFET for switching, which makes the Zener diode unnecessary and redundant.
Why the MOSFET Setup Is Better:
Efficient Switching:
A MOSFET like the SSF7509 (The one I used) is designed specifically for switching applications. It can handle high currents efficiently without the need to dissipate excessive power, as it has very low on-resistance (Rds(on)), meaning almost no power is wasted when it’s turned on.
High Current Capability:
MOSFETs can handle much higher currents compared to Zener diodes. For example, the SSF7509 can handle up to 75A, which is more than enough for typical relay-driving applications, even if your relay draws a few hundred milliamps.
Gate Control:
MOSFETs are voltage-controlled devices, which means they require minimal current at the gate to turn on or off, unlike Zener diodes, which would still need current through them to regulate voltage. The NVR output (seeing it provides only a small amount of current) can easily control the MOSFET gate, while the MOSFET does the heavy lifting to switch the relay on or off.
Clear On/Off States:
A MOSFET can provide a clean on/off switching capability, ensuring that when the NVR output is low, the relay stays off, and when the NVR output goes high (or provides a gate signal), the MOSFET fully turns on to power the relay. Zener diodes, on the other hand, don't provide a clear switching action like a MOSFET.
Flyback Protection:
When using a MOSFET, you can easily integrate a flyback diode across the relay coil to protect the MOSFET from inductive voltage spikes generated by the relay. Zener diodes wouldn’t offer this level of protection directly.
Using a MOSFET is far more appropriate for driving a relay from your NVR’s output, as it offers clean, efficient switching, handles higher currents, and provides better control. A Zener diode is not intended for this kind of application and could lead to inefficiency, excessive heat, or even component failure if the current exceeds its rating. The MOSFET setup is designed specifically for this kind of task, ensuring both safety and reliability in your circuit.
Why a Zener Diode Setup Can Be Problematic:
Power Dissipation:
Zener diodes are typically used for voltage regulation or clamping purposes, but they are not ideal for switching large loads like relays or for handling higher currents. Zener diodes are meant to maintain a specific voltage across them, but they will dissipate power and generate heat when conducting, which can become inefficient, especially with inductive loads like relays.
Current Handling:
Zener diodes are not designed to carry significant amounts of current. Relays, especially ones that require higher currents (e.g., 200mA or more), could potentially damage a Zener diode that isn't rated for such currents. Even if the Zener is rated for higher current, the setup would likely be inefficient compared to a MOSFET.
Voltage Regulation Only:
A Zener diode alone would not switch the relay on and off effectively. It would regulate voltage at a certain threshold (e.g., 12V), but that doesn’t provide proper control like a MOSFET, which can act as a switch to fully allow or block current flow. You’d have less control over when the relay is activated or deactivated.
Complexity of Proper Biasing:
Using a Zener diode would require a more complex circuit design to ensure proper biasing and control. You would likely still need to add a transistor or MOSFET for switching, which makes the Zener diode unnecessary and redundant.
Why the MOSFET Setup Is Better:
Efficient Switching:
A MOSFET like the SSF7509 (The one I used) is designed specifically for switching applications. It can handle high currents efficiently without the need to dissipate excessive power, as it has very low on-resistance (Rds(on)), meaning almost no power is wasted when it’s turned on.
High Current Capability:
MOSFETs can handle much higher currents compared to Zener diodes. For example, the SSF7509 can handle up to 75A, which is more than enough for typical relay-driving applications, even if your relay draws a few hundred milliamps.
Gate Control:
MOSFETs are voltage-controlled devices, which means they require minimal current at the gate to turn on or off, unlike Zener diodes, which would still need current through them to regulate voltage. The NVR output (seeing it provides only a small amount of current) can easily control the MOSFET gate, while the MOSFET does the heavy lifting to switch the relay on or off.
Clear On/Off States:
A MOSFET can provide a clean on/off switching capability, ensuring that when the NVR output is low, the relay stays off, and when the NVR output goes high (or provides a gate signal), the MOSFET fully turns on to power the relay. Zener diodes, on the other hand, don't provide a clear switching action like a MOSFET.
Flyback Protection:
When using a MOSFET, you can easily integrate a flyback diode across the relay coil to protect the MOSFET from inductive voltage spikes generated by the relay. Zener diodes wouldn’t offer this level of protection directly.
Using a MOSFET is far more appropriate for driving a relay from your NVR’s output, as it offers clean, efficient switching, handles higher currents, and provides better control. A Zener diode is not intended for this kind of application and could lead to inefficiency, excessive heat, or even component failure if the current exceeds its rating. The MOSFET setup is designed specifically for this kind of task, ensuring both safety and reliability in your circuit.
Be Safe.
Re: NV4232E-16P-EI Alarm Block Pinout
I agree, I suggested the MOSFET solution because I was unsure of your exact goal and thought that, since you're familiar with electronics, my approach might help others who can use similar techniques. I also mentioned another solution for those with NVRs that support RS485, who might need more than the two outputs already available. While I initially shared my setup with an alarm output board having only one relay, I later removed it. However, I posted it on my forum for anyone interested.
During testing, I discovered that even though the board has space for an additional relay, there was no connection between the relay output pads and the wire block, meaning simply adding a relay wouldn’t work without further modifications. I shared photos on the forum, allowing others to reference the datasheets for the relay, the quad differential comparators, and the TPS25924X e-fuse. I also provided detailed instructions about the MOSFET I used, including how it works and its connections.
Just trying to be helpful.
During testing, I discovered that even though the board has space for an additional relay, there was no connection between the relay output pads and the wire block, meaning simply adding a relay wouldn’t work without further modifications. I shared photos on the forum, allowing others to reference the datasheets for the relay, the quad differential comparators, and the TPS25924X e-fuse. I also provided detailed instructions about the MOSFET I used, including how it works and its connections.
Just trying to be helpful.
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Re: NV4232E-16P-EI Alarm Block Pinout
So would be interested in seeing the inside of your 4232-16P-E1 this is inside my Amcrest 5232E-16P and at the Push block you can clearly see 2 relays and it does have C1 NO1 C2 and NO2 printed on back.
- 20241021_200811.jpg (2.31 MiB) Viewed 4675 times
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Re: NV4232E-16P-EI Alarm Block Pinout
Thought I would post a draft not to scale Schematic of my circuit for others following and have the skills to make circuits, sorry can't do coils or resistors very well by hand lol don't know where my drafting box with my electronics templates. Not my best work, rough draft
- 20241022_014928.jpg (2.09 MiB) Viewed 4663 times
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Re: NV4232E-16P-EI Alarm Block Pinout
Yes but depending on the device. IF it says CTRL and P and not NO2 and C2 then there is going to be an issue even with a control circuit like you have posted a picture of. There is no dry contact relay in the NVR to make your device work. So that is why with a Mosfet and a relay you can control even a larger output device then what would normally be supported on the little Micro relays that are in the NVR.. While the last picture I offered was from my 5232E-16P NVR.. The other pictures show the E1 and it only has 1 relay and an empty spot where the second relay was normally on a different model that uses the same alarm board.. Because the output of 2 contacts are a low 12v current circuit that is why it will work with a Mosfet setup
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Re: NV4232E-16P-EI Alarm Block Pinout
Ok that is like my 5232E-16P NVR and shouldn't even have an issue with this.. The issue is the ones that only have 1 relay and 1 empty space where relay went.. In your NVR case the CTRL and P should just work as a NO relay already.. I would need to visit my 4216E-AI NVR because it also has the Block alarm pull out and does say CTRL and P but is just normal relay like NO1 and C1.
So no using a different relay in the spot shouldn't matter.. The issue is the Pins on the relay would still be the same and NO and NC are in different areas of the PCB it is soldered to. So no would need to use an external Relay to change from NO to NC state setup..
So no using a different relay in the spot shouldn't matter.. The issue is the Pins on the relay would still be the same and NO and NC are in different areas of the PCB it is soldered to. So no would need to use an external Relay to change from NO to NC state setup..
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Re: NV4232E-16P-EI Alarm Block Pinout
So wait.. you are saying that on your device it is NO for alarm 1 but NC for alarm 2? I would need to see the under side of the NVR PCB as I don't know why they would make such a change from all other devices that are already built?
If you wanted to have something to convert a NC to an NO then you would have to build a Bridge board and solder it in the NVR or again use an external relay to change from NC to NO setup.
I will admit I just looked up the Dahua Master and it is also setup with the same markings as yours so maybe there was some reason they did 1 NO and 2 as NC but I know in my 4216E-AI that has that same block as my 5232-16P they are both NO alarms.. I will have to find someone with the Dahua master and ask them to confirm how it is setup in the E1 for them because if it was NC that is just crazy..
If you wanted to have something to convert a NC to an NO then you would have to build a Bridge board and solder it in the NVR or again use an external relay to change from NC to NO setup.
I will admit I just looked up the Dahua Master and it is also setup with the same markings as yours so maybe there was some reason they did 1 NO and 2 as NC but I know in my 4216E-AI that has that same block as my 5232-16P they are both NO alarms.. I will have to find someone with the Dahua master and ask them to confirm how it is setup in the E1 for them because if it was NC that is just crazy..
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