What is 1uH, 0.1uH?

[Suraj143]

I see in many RF circuits it’s having a coil named with 1uH or 0.1uH.what is that?
So if I have 1uH in the diagram so how can I calculate that value? I have only the coil.
How do I place that?
How many turns in that?

 

[RODALCO]

The H stands for Henry which is the inductance value of the coil.
The value depends upon the amount of turns in the coil, the wire diameter, and the core material.
For a particular application you can wind a coil exactly the same or buy one of the value required.

The µ stands for micro or 1/1,000,000 th of.

 

[Suraj143]

Thanks RODALCO.

Now I have 1uH in the diagram. So how can I make that?
Here there’s no place to buy. I have the coil. (18SWG)

 

[Nigel Goodwin]

What is it for?.

 

[Suraj143]

Its in a transmitter circuit.I coudn't post it because it was in a book.And in another circuit I saw there is a 1uH coil.It's in a piezo circuit.

How can I make that coil to 1uH.Somebody pls help me.

 

[Nigel Goodwin]

There are endless transmitter circuits on here, you just need a few turns of thick wire around a pencil - accurate values are pointless, because stray capacitance and inductance make such a big difference.

 

[mvs sarma]

Hi Suraj143,

Nigel meant enamelled copper wire when he said 'wire'. then you have to clear the enamel at the ends of the coil to be able to solder it. Perhaps you may be already aware of it.

 

[ericgibbs]

hi suraj

Try this link, run the various simulations.

https://www.coilgun.info/mark2/inductorsim.htm

 

[Nigel Goodwin]

Hi Suraj143,

Nigel meant enamelled copper wire when he said 'wire'. then you have to clear the enamel at the ends of the coil to be able to solder it. Perhpas you may be already aware of it.

Actually I've always used bare copper wire, half a dozen turns round a pencil spaced slightly apart. I get the wire either from mains electrical wiring, or the inner core from coaxial TV cable.

 

[Optikon]

Actually I've always used bare copper wire, half a dozen turns round a pencil spaced slightly apart. I get the wire either from mains electrical wiring, or the inner core from coaxial TV cable.

geez, talk about scrimping to save a penny! If all one does is make air-cored inductors then its fine. The enameled stuff is nice in case you ever have to wrap it around some ferrite material (which is somewhat conductive)

 

[Nigel Goodwin]

geez, talk about scrimping to save a penny!

People in Yorkshire are renowned for been mean, and North Derbyshire borders on South Yorkshire!

But why waste time messing about cleaning enamel off, when it's not needed in the first place?.

 

[mvs sarma]

Actually I've always used bare copper wire, half a dozen turns round a pencil spaced slightly apart. I get the wire either from mains electrical wiring, or the inner core from coaxial TV cable.

That is fine,Sir. I only feared when one does close winding , possibly may land in trouble due to posible shorts-- thisvery doubt forced me to adda comment- which could avert further discussion on the iisue.

 

[Sceadwian]

Unless the windings are significantly spaced, even a good bump could cause direct contact.. Enameled wire is hardly expensive, and issolates the windings that much more.

 

[lord loh.]

There are some MH coils available in the market. These look like resistors bur are coils.... I never figured whether these were millihenries or microhenries...

 

[Nigel Goodwin]

There are some MH coils available in the market. These look like resistors bur are coils.... I never figured whether these were millihenries or microhenries...

'm' is milli, 'u' is micro (the greek letter 'mu') - a common value of such RF chokes is 1mH.

 

[mvs sarma]

These coilsare marked with a standard color code. It would not be difficult to decode. you may perhaps see the link below.

https://www.elexp.com/t_induct.htm

 

[Hero999]

There are endless transmitter circuits on here, you just need a few turns of thick wire around a pencil - accurate values are pointless, because stray capacitance and inductance make such a big difference.

I agree, but there's a large difference between a 100nH coil and a 1:mu:H, you at least need to be somewhere near the value. a good website which can help you to calculate the coil dimensions.

Anyway who said it's RF?

He said:

It's in a piezo circuit.

Could he be talking about ultrasound?

But 1:mu:H is pretty small for ultrasonic frequencies.

 

[mvs sarma]

I agree, but there's a large difference between a 100nH coil and a 1:mu:H, you at least need to be somewhere near the value. a good website which can help you to calculate the coil dimensions.

Anyway who said it's RF?

He said:

Could he be talking about ultrasound?

But 1:mu:H is pretty small for ultrasonic frequencies.

Mr Suraj has in his ist letter spoke about FR coils. and in his subsequent letter,he said "Its in a transmitter circuit.I coudn't post it because it was in a book.And in another circuit I saw there is a 1uH coil.It's in a piezo circuit."
the clear mention of RF in his 1st post repated with Transmittercircuit-- it is evident he was seeking info on rf coils....

Perhaps he might have meant Ultrasonic he might use higher cap values=

at this juncture Nigels reference to transmitter circiuts is very proper , I feel

 

[Hero999]

It could be an ultrasound transmitter.

I think he's such a nube that he probably doesn't really know.