AC10 PHILIPS [NXP Semiconductors], AC10 Datasheet - Page 5

• Manufacturer Part Number: AC10
• Description: Cemented wirewound resistors
• Manufacturer: PHILIPS [NXP Semiconductors]

BCcomponents
P
How to generate the maximum allowed pulse-load from the graphs composed for wirewound resistors of the AC-types.
Single pulse condition; see Fig.3
1. If the applied pulse energy in Joules or Wattseconds is
2. If, contrary to the information above, the applied
2000 Oct 20
ULSE LOADING CAPABILITIES
Cemented wirewound resistors
known and also the R-value to be used in the
application; take the R-value on the X-axis and go
vertically to the curved line. From this point go
horizontally to the Y-axis, this point gives the maimum
allowed pulse energy in Joules/ohm or Wattsec./ohm.
By multiplying this figure with -value in use gives the
maximum allowed pulse-energy in Joules or Wattsec. If
this figure is higher than the applied pulse-energy the
application is allowed. Otherwise take one of the other
graphs belonging to AC-types with higher P
peak-voltage and impulse times t
the pulse-energy (E
the following formula:
By dividing this result with the R
gives the value Wattsec./ohm on the Y-axis. Draw a line
horizontally to the curved line and at the intersection
the vertical line to the X-axis gives the maximum
allowed R
R
application, the application is allowed. If not, take one
of the other graphs belonging to AC-types with higher P
or change the R
Ep
n
-value is higher than the R-value to be used in the
=
Vp
--------- -
R
n
2
-value to be used in the application. If this
t
i
n
-value to be used.
(V
p
p
) in Joules or Wattsec. by the use of
= peak voltage; t
n
i
-value of the R in use,
are known. Calculate
i
= impulse-time)
n
.
n
5
Repetitive pulse condition; see Fig.2
With these graphs we can determine the allowed
pulse-energy in Watts depending on the impulse- time t
the repetition time t
Resistance Value. If the pulse shape is known (impulse-time
t
X-axis at the mentioned t
From the intersection the horizontal line to the Y- axis
indicates the maximum allowed pulse-load at a certain t
If the vertical line from the X-axis crosses the applied t
before reaching the R-line, this t
allowed pulse-energy at the Y-axis. If the applied
pulse-energy is known (in Watts) and the impulse-time t
also, draw a line horizontally from the Y-axis to the crossing
with the pulse-line (t
in this application. The horizontal t
maximum allowed pulse-load till they reach the R-line, that
point indicates the maximum allowed impulse-time ti at the
horizontal axis.
i
and repetition time t
AC01/03/04/05/07/10/15/20
p
i
) and find the possible R-value needed
of the pulses. The parameter is the
p
), draw a line vertically from the
i
to the line of the involved R-value.
p
/t
i
line gives the maximum
p
/t
i
Product specification
lines give the
i
p
and
/t
p
i
/t
i
i
.