Contact Closure Push Notification for MQTT over WiFi input voltage limit


Recently a Contact Closure Push Notification for MQTT over WiFi module was put upon my desk with a note to make it work. No manuals, no cables, no power supply.

The sticker on the rear of the device states the input voltage to be 4 - 12 Vdc, but it seems to need at least 6Vdc to power up properly.

I visited the NCD website, and the relevant pages provided me with an additional 2 sets of voltage input figures:

So my question to you is which set of figures for the input voltage range is correct?

For our application a 24Vdc rail already exists, so being able to run off 24Vdc would be optimal.
(my fingers are crossed that you say that the 6-32VDC input figure is correct)



@Bhaskar who is the developer of the electronics in that device has confirmed that 24VDC can be used to power it.

Let us know if you have any other questions.

Thank you,

Thanks @TravisE_NCD_Technica and @Bhaskar .

Can you advise what the upper voltage limit is please? Our 24V rail can experience small upward excursions under some circumstances, and we need to ensure these won’t blow the NCD module.

I ask because a glancing inspection of the module suggests that its input circuitry consists of a bridge rectifier followed by a 25V tantalum cap - which suggests minimal headroom when powered from 24V.


all parts are designed with 10% tolerance.