Products > Test Equipment
Does anyone here use the Peak Lcr45? Max Inductance?
rwgast_lowlevellogicdesin:
I had no idea the voltage effected inductance that much! If your just measuring windings to get there to calculate there ratio yo each other i wouldnt think the absolute measurements would matter?
Martin72:
You would have to try it out, I can do it tomorrow, then also with an Atlas LCR, but also div others at work.
The ratio between primary and secondary windings is best measured with a voltage supply.
For example, you feed in 50Vac primary, if you then measure 5Vac secondary, you know the ratio (1:10).
If you want to know the number of windings, you have to determine at least one side, the other results from the ratio(or measure it too).
Only works with non-potted transformers:
-Loop a wire around the core (equal to one turn).
-Apply voltage to the winding of which you want to know the number of turns.
-Measure the voltage on the one wire.
-Example: Supply 20Vac to the winding, measure 100mV on the one wire = 200 turns.
-Polarity test:
Measure voltages with an oscilloscope, 1 channel primary, 1 channel secondary, view phase relationship.
And so on...
Grandchuck:
--- Quote from: rwgast_lowlevellogicdesin on August 11, 2024, 06:20:25 pm ---I had no idea the voltage effected inductance that much! If your just measuring windings to get there to calculate there ratio yo each other i wouldnt think the absolute measurements would matter?
--- End quote ---
Shown below is another example at 0.1V, 0.5V, and 1V at a frequency of 100 Hz. At 10 kHz, there is much less variation due to excitation voltage and the readings are all around 8 H.
rwgast_lowlevellogicdesin:
When you buy a standard inductor, and it is idk 10microHenerys lets say, how do they get that number. I know that there usually tested at 100khz or whatever but what is the standard voltage used?
I really wish there was something like the Bode frequency analyzer at a reasonable price. Once you get to RF and everything is 50ohm and you can use a VNA measuring this stuff is so much easier. I will probably never need to wrap or use an inductor in a circut using 2v or less.
Lets say im working on a 50v 500khz boost converter and i need to wrap a 10microHenery as part of the circuit, is there any way to test my inductor without breaking the bank. At this point i feel like there are a lot of situations where you just pick a core material use a winding calculator and call it a day!
Martin72:
--- Quote from: rwgast_lowlevellogicdesin on August 11, 2024, 10:19:11 pm ---When you buy a standard inductor, and it is idk 10microHenerys lets say, how do they get that number. I know that there usually tested at 100khz or whatever but what is the standard voltage used?
--- End quote ---
It is usually stated in the data sheet how the measurements were taken.
So with chokes, transformers have to be assessed differently again.
With normal mains transformers, inductance is more of a nice to know.
With high-frequency switching power supply transformers, the situation is different, depending on the topology used.
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