Tags Posts tagged with "Passive"


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0 2025

We’ve made it to the 4th video and in this video so moving on from our last video investigating variable frequency filters using analogue switches, we now go into more advanced variable filters using multipliers. As per usual we go through the theory and then show some results from some real circuits, as well as leaving you with some other options for making filters variable.
We also cover some common errors that are made when making filters variable and look at techniques to make the ranges covered larger, expanding to several decades of range.
For some examples covering the initial design of fixed frequency filters, see some of the earlier videos and in the next few videos, we’ll get the PCB assembled and take some measurements on a system which covers multiple decades, working towards a useful bit of lab equipment.

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0 2039

This is the third video in our filter design series and we’re finally looking at variable filters! We’re starting off with an overview of some basic techniques and then switched resistor techniques in detail, building up an example and measuring it’s performance.
To get started, you can use the spreadsheet that we’re covered in our previous video here to design it for the highest frequency, and then use the techniques covered here to make it variable.
In the next video we’ll cover some more advanced techniques for variable filters still moving towards a microcontroller controlled filter.

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0 1898

In this, our second tutorial video about filter design, we build on the topics that we covered in the last video. This time we take you through the steps to design a state variable filter of a fixed frequency. As a bonus, we also cover some of the nuances of prototyping precision analogue circuits.
The spreadsheet we talk about in the video can be found here, and should get you started with designing your own filters.
Following on from this in the next video we’ll start to investigate some of the techniques for making variable filters, controllable by a microcontroller or from analogue electronics.