BMG is a product encapsulated by self-developed ultra-thin gas discharge tube and varistor in series.

Fully compatible with the existing MOV pad size.

The BMG products provided to customers are from 7mm~20mm  diameter, surge rating from 1KA to 5KA, the maximum continuous working voltage is 70VAC~600VAC, and the working environment temperature supports -40℃~105℃.

Compared with a simple varistor, BMG has the following advantages:

Improved AC voltage withstand 

The varistor is connected in series with the gas discharge tube. Due to the large difference in static impedance between the two, most of the voltage is applied to both ends of the GDT, which determines that the starting

impulse break over voltage of the protection circuit .Impulse breaking voltage is determined by GDT, not MOV.

Improved residual voltage of the design

Due to the high-impulse break down voltage of GDT connected in series, the MOV only needs to be responsible for protecting working voltage.

So the varistor voltage of  the design can be reduced. For example, in the AC220V circuit, the original configuration Choose 470V MOV, or even 560V MOV.

When choosing BMG products, the corresponding varistor voltage can be 330V or 390V to meet the needs of low platform residual voltage.

Effective cut off the leakage current of MOV in parallel in the circuit

Due to the addition of GDT, the leakage current of BMG is very small, less than 0.1μA, before the breakdown state is reached, so the sensitive leakage current loop is cut off.

The conventional varistor can only reach the μA level when it is 0.75*V@1mA, but if the power grid fluctuates, it may reach a larger leakage current. And speed up aging of the MOV and may even catch up fire.

Failure mode of BMG module is obvious

Based on large number of tests, having the GDT connected in series, the failure mode is probably MOV wear out failure, and there is very small probability for BMG hybrid for catching fire or combustion because of the GDT in serie connection with MOV.