Need help to understand the datasheet of an inductor...

high open circuit inductance need

Part: HC2LP-4R7
Description: 4.7uH
Manufacturer: Coiltronics

Pls help me to understand the following parameters:
1) What is OCL? (OCL: Open Circuit Inductance)
2) What is V-µS? (V-µS: Volt-Time product)
3) How to interprete the "% of Losses from Irms (maximum)" vs "% of Applied Volt-µ-Seconds" plot?
4) Pls refer to note (2): DC current for an approximate temperature change of 40°C without core loss. Derating is necessary for AC currents. What does this note try to tell?

Pls share if you have some interesting 'practical' views...

Thanks.

What is OCL?
It is the value of inductance at no connection in circuit.
2) What is V-µS?
It is the parameter which shows that in this measure, the inductor will be saturated.

hamdard said:

What is OCL?
It is the value of inductance at no connection in circuit.

Click to expand...

Without connection how to measure the inductance? Thanks.

Method for Measuring Inductance


h**p://www.oz.net/~coilgun/theory/measureinductance.htm

h**p://engr.nmsu.edu/~etti/fall96/electronics/induct/induct.html

using an inductance bridge or meter.
more on this site
h**p://www.sxlist.com/techref/inductor/measure.htm

First of all you should notice that the inductance in question is design for work at high currents. The coil inductance is constant for very small and small currents, but coil inductance is lowering when peak current (that is flawing through the coil) approach the coil nominal current value.
So the "Open circuit inductance" is rather the "Coil inductance measured at currents significantly lower than the nominal working current".

There is an analogy with EMF (open circuit voltage of electricity source) and real Voltage .

AndrzejM said:

First of all you should notice that the inductance in question is design for work at high currents. The coil inductance is constant for very small and small currents, but coil inductance is lowering when peak current (that is flawing through the coil) approach the coil nominal current value.
So the "Open circuit inductance" is rather the "Coil inductance measured at currents significantly lower than the nominal working current".

There is an analogy with EMF (open circuit voltage of electricity source) and real Voltage .

Click to expand...

I see... Thanks for your explanation. Could u pls help me to clarify other questions mentioned in the first post of this thread? Thanks.

For DC and frequencies lower than 100 kHz only the current that is flowing through the coil rise up its temperature. According to technical data, the coil temperature should not rise up above 60 degree ( 40 degree above the 20 degree ambient temperature).
This is the reason why the current is limited to value given in the column (2).

When the frequency is higher the magnetization losses starts to play significant role.
For coil HC2LP-R47-R at 300 kHz and V usek = 6.87 10 % of temperature rise up cames from magnetic phenomena and 90 % from the current flowing through the coil resistance. So, to avoid overheating the maximum current value should be corrected and kept lover than that given in column (2).