thermionic
Well-known member
- Joined
- Jun 3, 2004
- Messages
- 1,671
Hi,
Recently, I’ve been spending time optimising various LC equalisers. The hard design work is done (not my design) and the circuitry works well / sounds good. My query here is for the purpose of perfecting the centre points.
It occurred to me that it *should* be relatively easy to make a simple X / Y plot using a basic piece of software, the idea being – in my case – that I already have a fixed value for the inductor, with the software enabling me to draw a line and see a corresponding cap value for the desired centre frequency.
I’m currently using the following tried-and-tested formula:
Centre Frequency = 1 / (2pi * sqrt(L x C))
In the above example, L represents my inductor value in Henrys and C equals the cap value in microfarads. In my case, I already have the inductor in place on the PCB and I’m looking to print off a handy paper reference for each of the bands when I’m selecting caps.
For example, I might plot frequency along the Y axis, and capacitor value across the X axis.
The problem is it’s nearly 20 years since I studied this in school…
I’ve been looking at a few freeware graph plotting programmes, but the selection seems enormous and the couple I’ve tried find faults in my syntax…(I should’ve paid more attention at school). The syntax for the above formula works fine with Google calculator and mirrors results from the calculator here: http://www.opamplabs.com/cfl.htm
I realise that I could take values from manual calculations and plot a graph on paper, but I was wondering if anyone could suggest a software option (preferably one the person has tried!) to save time.
Many thanks in advance.
Justin
Recently, I’ve been spending time optimising various LC equalisers. The hard design work is done (not my design) and the circuitry works well / sounds good. My query here is for the purpose of perfecting the centre points.
It occurred to me that it *should* be relatively easy to make a simple X / Y plot using a basic piece of software, the idea being – in my case – that I already have a fixed value for the inductor, with the software enabling me to draw a line and see a corresponding cap value for the desired centre frequency.
I’m currently using the following tried-and-tested formula:
Centre Frequency = 1 / (2pi * sqrt(L x C))
In the above example, L represents my inductor value in Henrys and C equals the cap value in microfarads. In my case, I already have the inductor in place on the PCB and I’m looking to print off a handy paper reference for each of the bands when I’m selecting caps.
For example, I might plot frequency along the Y axis, and capacitor value across the X axis.
The problem is it’s nearly 20 years since I studied this in school…
I’ve been looking at a few freeware graph plotting programmes, but the selection seems enormous and the couple I’ve tried find faults in my syntax…(I should’ve paid more attention at school). The syntax for the above formula works fine with Google calculator and mirrors results from the calculator here: http://www.opamplabs.com/cfl.htm
I realise that I could take values from manual calculations and plot a graph on paper, but I was wondering if anyone could suggest a software option (preferably one the person has tried!) to save time.
Many thanks in advance.
Justin