Of course, this doesn't cover all the possible diode circuits - just the ones that are probably worth knowing about in general electronics practice.
As an example of more obscure designs, a non-conducting diode can be also thought of as a tiny parasitic capacitor in which the capacitance can be varied by the applied reverse-bias voltage (this widens or squishes the depletion region in between). You can build some clunky voltage-controlled oscillators that way... but probably shouldn't.
In the same vein, diodes combined with multiple center-tap transformers used to popular for radio frequency mixing; nowadays, transistor- or op-amp-based circuits are both easier to construct and better-behaved, so there's little value in diving into that topology.
Bonus point: everything you can do with normal diodes can be done with any other p-n junction that you happen to have at your disposal. In particular, you can build a rectifier with LEDs, photodiodes, or transistors with one leg clipped off.
- voltage multipliers that let you convert AC into DC that is several times larger than the AC p-p voltage
- demodulators that let you detect amplitude modulated signals
- parallel and opposed conventional diodes which form a crowbar similar to the opposed Zeners, but simpler because of the lack of a need for a special diode (and limited to very low voltages)
- diodes + op amps to get nearly ideal rectification
Diodes are great. They are also nearly bomb-proof and thus excellent for early experimentation.
Of course, this doesn't cover all the possible diode circuits - just the ones that are probably worth knowing about in general electronics practice.
As an example of more obscure designs, a non-conducting diode can be also thought of as a tiny parasitic capacitor in which the capacitance can be varied by the applied reverse-bias voltage (this widens or squishes the depletion region in between). You can build some clunky voltage-controlled oscillators that way... but probably shouldn't.
In the same vein, diodes combined with multiple center-tap transformers used to popular for radio frequency mixing; nowadays, transistor- or op-amp-based circuits are both easier to construct and better-behaved, so there's little value in diving into that topology.
Bonus point: everything you can do with normal diodes can be done with any other p-n junction that you happen to have at your disposal. In particular, you can build a rectifier with LEDs, photodiodes, or transistors with one leg clipped off.
Some of my favorite diode circuits are
- voltage multipliers that let you convert AC into DC that is several times larger than the AC p-p voltage
- demodulators that let you detect amplitude modulated signals
- parallel and opposed conventional diodes which form a crowbar similar to the opposed Zeners, but simpler because of the lack of a need for a special diode (and limited to very low voltages)
- diodes + op amps to get nearly ideal rectification
Diodes are great. They are also nearly bomb-proof and thus excellent for early experimentation.
Interesting, thanks.
Very good tutorial. People forget how useful simple analog circuits like this are.