Archive for the ‘Capacitance meter’ Category

Capacitance meter (Part 4)

Part 1, 2, 3, 4 While the principle of operation is correct, the previously described assembly has limitations. It cannot handle the full range of expected capacitance values. Not enough data points are acquired for small capacitors (pF range) and it would take ages before getting the value of large capacitors (F range). This issue can be easily bypassed […]

Capacitance meter (Part 3)

Part 1, 2, 3, 4 Let’s talk about the code for a while. Here is the sequence of commands that we will execute: Charge capacitor Start discharge cycle Acquire scanned data Compute time constant Compute Capacitance Format and print result Wait for completion of discharge cycle Loop back The tirikiest part of the code is probably the calculation part […]

Capacitance meter (Part 2)

Part 1, 2, 3, 4 Before getting further on with maths and code, let’s have a look to the electronics. The proposed circuit is as usual as simple as possible. However, care shall be taken with the choice of components. The resistor has a high ohmic value. If you cannot get a precision resistor, you will have to measure […]

Capacitance meter (Part 1)

Part 1, 2, 3, 4 Identifiying a capacitor is no big deal as long as the labelling is readable: Depending upon the package type, we will use some conversion formula, like: However, identiying a surface mount capacitor may be tricky! In this case a capitance meter is necessary. There are some available on the market, but why buy one […]