Matching diodes.

[Pehr]

The Yusynth Wavefolder requires 1N4148s matched in pairs. I know how to match transistors (I think), but how does one match diodes?

Does anyone know?

[Pehr]

0k 0k, I should have googled before I wrote hehe

[yusynth]

If you have a modern DVM, you have a position to test diodes, the procedure then is to select the diodes that exhibits the same direct voltage drop down to the mV.

If you haven't that function in your DVM you can use a very simple circuit, a 9V battery a 68K resistor (for a current around 0.1mA) and the diode to be tested. Connect the diode in series with the resistor and the battery such that the diode is polarised in direct mode (conductive mode). Then measure the voltage drop of the diode.

By the way here the diodes need be matched such that the waveshaping be symetrical with respect to 0V. In the waveshaper each diode of the pair defines the local shape of the curve, one for the positive voltage and the other for the negative voltage, that's why they must be identical to achieve the very same shape.

[Pehr]

Thanks for the answer Yves! That explaines it.

I hope my DVM has that feature, otherwise I'll just measure the voltage drop.

Cheers

[a.b.o.z.]

And, how to match capacitors?

[yusynth]

With a capacimeter (function available on most of the multimeters, simply measure the value of the capacitors and select those within a given tolerance window.

[6079smith]

I'm going to knock up a simple Wheatstone Bridge specifically to match passive components... something like this (scroll down to the appendix near the end).

[Funky40]

[a.b.o.z.]

Thnx smith.
175 years old technology and still doing its job.
great.
I'm amazed!

[Peake]