paulvg01

modified 7 years ago

Strange modulator

185

01:52:29

I seem to have created a rather strange sort of modulator.

published 7 years ago

hurz

7 years ago

i dont see a "modulator" adding both waveshapes together green + orange is what blue is http://everycircuit.com/circuit/6594577443323904

eekee

7 years ago

What's strange here is the pot has no effect. The signal is already mixed.

eekee

7 years ago

What's less strange is a 1GR load is enough to change the output; it's a 10Hz signal through approximately 10pF. Short the pot, connect 1GR from short to ground.

hurz

7 years ago

right, the circuit can be anything as long its somehow just adding the signals together but NOT modulating them check this just adding both signals is what this circuit does http://everycircuit.com/circuit/5122911831851008

hurz

7 years ago

in the moment it would "modulate" something, two signals would be generate a third different waveform from which we cant go easily back to the original wave shapes.

eekee

7 years ago

Um.. I don't know about "can't easily go back.." This is addition (or literally averaging). Is AM usually multiplication? I'm not sure any more.

eekee

7 years ago

Ah, addition doesn't make AM: http://everycircuit.com/circuit/6682960790290432

hurz

7 years ago

right, for AM it needs multiplication, but multiplying two frequencies is not pure AM, there are more artefacts inside the result. The sum of both frequencies and also the delta of both plus a less importante constant voltage.

eekee

7 years ago

The sum and the difference are the sidebands; get rid of those and you lose the AM. :)

hurz

7 years ago

and the constant part?

paulvg01

7 years ago

I've just now read through the comments, examined the actual output, and realised that I may actually be concussed.

hurz

7 years ago

and right, an addition makes nothing. No AM both signals are still perfectly present as the original ones. Nothing changed to the signals applied.

eekee

7 years ago

@hurz: I see what you mean. I agree now.

eekee

7 years ago

@paulvg01: EveryCircuit MOSFETs have that effect! :D I think it's because there's no parasitic capacitance or inductance which in real life would dissipate the strange signal before it could be seen.

hurz

7 years ago

even hundreds of tera ohm wont stop everycircuit to add wave shapes to something looking nice. But in practical its totaly useless. Here the mosfets are doing nothing, as i said and can be replaced by hundreds of tera ohm resistors.

paulvg01

7 years ago

@hurz Presuming, of course, that you <i>have</i> hundreds of 1TΩ resistors lying about the shop... Haha

hurz

7 years ago

difficult, the normal air humity will cuz lower resistance

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