making/buying 680 uH inductors

P

pc88

New Member

• Jul 18, 2008

• #1

I have a schematic for a WWVB reception indicator which calls for 3 680uH inductors.

I was wondering if this part would work (Mouser part no. 434-17-681J).

http://www.mouser.com/Search/ProductDetail.aspx?qs=rllIVGd7HzlAluYgjASlmQ==

Alternative, could I get away with something like this (cheaper but lower Q):

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=M8156-ND

Finally, if I had to "roll my own", how would you go about doing it?

Thanks!

FWIW, they are all part of LC-tanks (freq. around 60 KHz), so I figure I can compensate for inexactness in the inductance value on the capacitance side.

 

k7elp60

Active Member

• Jul 18, 2008

• #2

I would think they should be okey. One thing in buying or winding your own inductors, the maximum DC current is a factor. But since these have a maximum current of 170mA and it is a receiver I see no problem.

 

M

mneary

New Member

• Jul 18, 2008

• #3

I would go with lower tolerance or higher Q. This is without seeing the circuit which could make a difference.

Can you post the WWVB circuit, or a pointer?

 

P

pc88

New Member

• Jul 18, 2008

• #4

Here's a LTSPICE schematic. The circuit appeared in Nuts and Volts, May 2006 on page 111.

Now that I've entered the schematic into LTSpice, one problem I'm having is that I cannot reproduce the frequency response plot. The plot in the article shows a gain of 60 db at 60 KHz, but I'm not getting anywhere near that.

I uploaded a the schematic and response plot from the original article.

 

Attachments

• WWVB reception amp.asc

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• WWVB reception amp.png

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• WWVB reception amp - kincaid.png

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Last edited: Jul 18, 2008

M

mneary

New Member

• Jul 18, 2008

• #5

First problem I see (from left to right) is L4 is 703.6 nanofarads.

 

Last edited: Jul 18, 2008

P

pc88

New Member

• Jul 18, 2008

• #6

Henries, Farads - ack!

Okay - that fixed it - thanks!

 

S

Speakerguy

Active Member

• Jul 18, 2008

• #7

You can probably buy .68mH air core inductors from loudspeaker companies.

 

Hero999

Banned

• Jul 19, 2008

• #8

You make the 700nH inductor yourself, although you could probably use a 680nH and it'd make little difference.

He's talking about the larger 680µH inductors which can be bought from many suppliers. They only have to be low current, an ESR of 10Ω is probably acceptable. I advise buying them rather than making them because they'll be much smaller and have a higher Q.