Build a low voltage, high voltage and surge protector

Thread Starter


Joined Feb 4, 2023
I want to protect my LED TV from low and high voltages and also from voltage surges. Required output voltage range 200 - 250 V AC (RMS).
I want to make it simple and effective one. Which one of these two options work best and please recommend other solutions

1. Just use V275LA40BP to protect from high and surge voltages due to lightning
2. Along with option 1. Monitor the input voltage using zmpt101b sensor and a microcontroller and then switch on/off relay based on the input voltage.


Joined Jan 15, 2015
Most modern TV sets have an input voltage range of 90 to 250 VAC RMS 50/60 Hz.

Depending on point of origin mains voltage remains within that window. Figure it this way, if in a location where spikes in mains voltage are common you need to consider how fast a spike happens and how fast your electronics protection can respond. Also consider your protection electronics are linked to the same power source as your TV.
Lightening is another interesting topic. If lightening strikes close enough on your mains power everything in the path will be dead, fried crispy. Yes, you can use a V275LA40BP or several configured as surge protection or any similar metal oxide varistor but like everything else they have their limits. So again it comes down to location and how reliable your mains voltage supply actually is.

The ZMPT101b is just the transformer part number. Most for use with a uC come on a modular circuit board. If your uC and ZMPT module are powered from the same mains source it's a shootout what will fail first. Consider when the field of a relay coil begins to collapse to where the contacts open is time. So how fast will a clean disconnect actually be?



Joined Jan 23, 2018
A very dependable brand of protection devices adds two stages of series common mode filters plus individual line filters, in addition to the over voltage protection devices. The filter block bot noise AND those fast spikes that might get past the over voltage devices. So adding some filters will increase the fast spike protection.


Joined Aug 21, 2008
Many consumer products already have surge protection as part of the circuit and under voltage protection is also inherent in most designs. I suggest that you find out what standards your LED meets and from there determine whether or not further protection would be of any value.