pl help with inductor winding

[ash]

how can i wind an accurate [1%] 10uH at home ?

 

[Robert Baer]

how can i wind an accurate [1%] 10uH at home ?

Use a fairly stiff wire on a solid plastic form, and use the standard
tables to convert turns and dimensions of the coil into inductance (work
backwards from a proposed size).

 

[Ian Stirling]

how can i wind an accurate [1%] 10uH at home ?

Wind, measure, wind/unwind some, repeat.
Measurement can be done with the aid of a known capacitor, or a
RLC meter.

 

[John Woodgate]

how can i wind an accurate [1%] 10uH at home ?

For what frequency range?

 

[Paul Burridge]

how can i wind an accurate [1%] 10uH at home ?

For what frequency range?

Q?

 

[Peter O. Brackett]

Ash:

This will be a small air core coil, cuz, 10 uHy is a "small" value.

A few (7 - 8) turns of #22 copper wire wound tightly around a number two
pencil, as a pre-form, for the solenoidal coil should do it.

You will have to iterate towards the final 1% value by adjusting the coil
after it is
wound.

And you need a method of measuring the coil. If you don't have an accurate
LCR bridge that can handle it, I suggest resonating it with a known
capacitance
and measuring the resonant frequency with a cheap "GDO". Count the
frequency
of the dip with an accurate frequency counter. This is the way I do it.

Do this by sliding the pre-wound coil off the pencil former to get the
air-core solenoid,
then stretch or compress the solenoid or cut some turns off and
stretch/compress again
while measuring to obtain the final value.

Been there done that lotsa times, it works.

 

[Reg Edwards]

how can i wind an accurate [1%] 10uH at home ?

======================================

Easy! Do you want a big coil or a little coil ?

ONE turn of 18 awg wound on a former 6.76 feet in diameter has an inductance
of 10 micro-H.


Or, for something smaller, wind 38 close-wound turns of 0.010" diameter,
enamel insulated wire on a 0.394" diameter former, 0.394" long.


But forget about an accuracy of 1 percent. You won't be able to manufacture
the things at home to that degree of accuracy. Think in terms of 5 percent
and then prune the length of the connecting leads.


If anybody should need a precise value inductance, which is extremely
unlikely, just put a ferrite or brass threaded slug inside it.


To measure inductance with an uncertainty better than 1 percent at say 10
MHz try the State Weights and Measures Standards Laboratory if you have one.


For coil design download in a few seconds program SOLNOID3 from website
below and run immediately. No training course needed.

First choose coil former dimensions to suit your application. Then vary
number of turns until you have the required inductance. Other calculated
results - self-resonant frequency, Q, stray capacitance, temperature rise
for given applied volts, etc., etc. All within milli-seconds.
----
............................................................
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
............................................................

 

[Robert Baer]

how can i wind an accurate [1%] 10uH at home ?

Wind, measure, wind/unwind some, repeat.
Measurement can be done with the aid of a known capacitor, or a
RLC meter.

That method is unacceptable for home use, as the measuring equipment
must be better than 1%.
Winding an air-core inductor according to known formulas can give good
results, with care.

 

[Ian Stirling]

how can i wind an accurate [1%] 10uH at home ?

Wind, measure, wind/unwind some, repeat.
Measurement can be done with the aid of a known capacitor, or a
RLC meter.

That method is unacceptable for home use, as the measuring equipment
must be better than 1%.

Not especailly hard.
Grid-dip meter can be constructed from a few parts.
Calibration against a MW radio can get you within a couple of hertz
easily, though making a scale isn't easy.
This gets you to +-10% without trouble.

Using a simple digitally tuned radio can get you to within 1% easily.