Brochure

Metal Oxide Varistors are widely used across many markets
and applications. Currently, designers use discrete circuit
protection devices in multiple configurations to address threats
from unstable electrical service. Whereas discrete solutions
have not necessarily been proven in real world situations, the
GMOV™ hybrid overvoltage protector solution has been tested,
evaluated and shown to be effective against many of the threats
it will experience in the field.
Bourns® GMOV™ hybrid overvoltage protectors can be
utilized in all the major market verticals such as industrial,
consumer, medical (low/medium risk)* and communications.
Examples of uses for GMOV™ components include Surge
Protective Devices (SPDs), surge strips, white goods, chargers,
solar power, medical electronics (low/medium risk)*, and data
line over power applications. In general, almost any application
that is powered by AC or DC can utilize a GMOV™ component
for overvoltage protection.
The table above compares several different protection options
available for a hypothetical 120 V
rms
application. In summary,
the standard 130 V MOV solution provides the least effective
overall performance when comparing clamping voltage,
leakage, aging characteristics and responses to temporary
overvoltages (TOV). In some cases, a higher voltage 275 V MOV
can be used to help mitigate leakage and aging issues. Leakage
and aging performance is improved by selecting a varistor
voltage that is far above the peak system voltage. However,
a temporary overvoltage condition could still result in excess
leakage and some damage to the MOV. The big disadvantage of
this solution is the higher let-through voltage of the 275 V MOV
as compared to the 130 V MOV solution.
The third example illustrates how a thermally protected
130V MOV component provides similar performance as the
standard 130 V
rms
rated MOV but with an integrated thermally
activated fuse that disconnects the MOV from the AC line
during a catastrophic failure event. The thermally fused option
assumes the MOV will fail but in a safer mode than the failure
of a standard MOV. In contrast to the first three options is the
Bourns® GMOV™ component. The GMOV™ solution provides
similar clamping voltage as compared to the 130 V rated MOV
and a superior level as the 275 V MOV. The GMOV™ design
isolates the MOV from AC line voltage, resulting in excellent
leakage and aging characteristics while at the same time
achieving a higher level of tolerance against damage from
temporary overvoltages.
MARKET OVERVIEW
CIRCUIT DIAGRAM
BOURNS® GMOV™ COMPONENT vs. STANDARD MOV
Technology Clamping Voltage Leakage Current Aging 30 % Voltage Swell Response
130 V MOV 340 Poor Poor Possible Fire
275 V MOV 710 Good Good Increased Leakage
130 V MOV + TF 340 Poor Poor Possible Fire
GDT + MOV ~360 Excellent Excellent Excellent
* Bourns® products have not been designed for and are not intended for use in “lifesaving,” “life-critical”
or “life-sustaining” applications nor any other applications where failure or malfunction of the Bourns®
product may result in personal injury or death. See Legal Disclaimer Notice http://www.bourns.com/
docs/legal/disclaimer.pdf.