3111 N. Deer Run Road, Suite 4
Carson City, NV USA 89701
800-808-2434 / 775-884-2434
Fax 775-884-0670 / www.ametherm.com
Circuit Protection Thermistors
Ametherm’s bigAMP™ Inrush Current Limiters
are specially designed to withstand up to 36
amperes of continuous current and 260 joules
of input energy.
The bigAMP Inrush Current Limiter is useful in:
➤
Switching power supplies
➤
AC Motors
➤
Uninterruptible Power Supplies
➤
Frequency Generators
➤
Other equipment that can be improved
with inrush current protection
When electrical equipment is turned on, the
bigAMP Inrush Current Limiter absorbs high
amounts of inrush current by offering a high
resistance to current and quickly decreasing in
resistance once steady state current begins to
flow through the thermistor. In a switching power supply, the instantaneous surge energy is
caused by the large input filter capacitors and AC input voltage.
During the absorption of energy, the
initial high resistance of the thermistor
drops within milliseconds to a negligible
resistance in preparation of allowing
high levels of steady state current to flow
with a minimal loss of power through the
circuit. The bigAMP™ Inrush Current
Limiter will absorb up to 260 joules of
input energy and carry 36 amperes of
steady state current.
➤
Use the maximum allowable inrush
current and Ohm’s Law to determine
the least allowable resistance at turn
on for your application.
➤
Using the formula J=
1
/
2
CV
2
,
determine how much input energy the
thermistor will absorb when the
device is turned on.
➤
Determine the maximum steady state
current that will flow through the
Inrush Current Limiter.
➤
Select the Inrush Current Limiter that will work for your application.
How does the
bigAMP
Inrush Current
Limiter work?
One example of a typical circuit for limiting
inrush current.
How to specify
the right bigAMP
Inrush Current
Limiter for your
application:
Another example of a typical circuit for limiting
inrush current.
File No. CA 110861
File No. E209153