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"Amplification occurs because a relatively small DC control current can modify a much larger AC load current." Doesn't the larger AC load current itself also s
by Aardwolf 5y ago
"Amplification occurs because a relatively small DC control current can modify a much larger AC load current."
Doesn't the larger AC load current itself also saturate the core though, overpowering whatever the much weaker current does? Or is only DC current able to saturate it?
- kragen 5y agoThat would be true at the same number of turns, but Ken explained that the control winding has more turns, in effect multiplying its current.
- Aardwolf 5y agoTo use them in a computer for logic gates, if you want to have multiple logic gates work together (such as an adder where bits propagate through many gates), does that then mean you'd need to convert AC outputs to DC control inputs for every single connection between gates? Or is there some more efficient way they did this?
- kragen 5y agoI think that is correct. But maybe you can use diode logic instead for most of your gates, resorting to ferrite only when you need inversion, amplification, or memory.
- kens 5y agoFor logic gates, the signals are pulses, so it doesn't really make sense to categorize them as AC or DC. If you want the exact circuit, take a look at the Univac Solid State manual page 6-89: http://www.bitsavers.org/pdf/univac/uss/UNIVAC_7900_Central_Processor_90_Theory_of_Operation_Service_Manual_No_1.pdf http://www.bitsavers.org/pdf/univac/uss/UNIVAC_7900_Central_...
- kragen 5y agoThank you! I've been looking for good info for years. You don't happen to know about Soviet ferrite/diode systems, do you?
- kens 5y agoSorry, no, I haven't come across any information on Soviet systems.
- kragen 5y agoApparently, due to lagging semiconductor fabrication technology, they were the state-of-the-art devices in the USSR even several years after losing to transistors in the US. I was terribly confused when I first heard about "ferrite-diode systems" since you obviously can't make a diode out of ferrite!