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[youtube=”http://www.youtube.com/watch?v=vBsSASge7ls”]
In this video, Jeri Ellsworth thinks back to her childhood, to oscillator circuits she used to see using incandescent lightbulbs, and explores the utility of such a seemingly lame design. You may be surprised by the results. The circuit she builds and tests is called a Wien bridge oscillator.

[youtube=”http://youtu.be/y1w6Nskbx8E”]
Here, Jeri describes and then examines static vs. dynamic flip-flop circuits. A flip-flop is a circuit that can store state information and is part of the foundation of digital electronics.

Gareth Branwyn

Gareth Branwyn

Gareth Branwyn is a freelancer writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor for Boing Boing and WINK Books. And he has a new best-of writing collection and “lazy man’s memoir,” called Borg Like Me.


3 Responses to Jeri Talks Bridge Oscillators and Flip-Flops

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  1. miroslava von schlochbaum on said:

    as usual very nice videos! (any from Collins ever again?)

    bloody nice tektronix/series:MSO/DPO4000B oscilloscope there. ~$10k!

  2. Gareth Branwyn on said:

    Jeri’s a rock star. Rock stars always have fancy axes.

  3. Few notes on the flip-flops video:
    Static flip-flops are the base for SRAM (http://en.wikipedia.org/wiki/Static_random-access_memory) while dynamic flip-flops are used in DRAM (http://en.wikipedia.org/wiki/DRAM).

    Jeri mentions Dynamic flip flops require less transistors but they have a drawback. due to the use of capacitors as ‘memory’ they require constant ‘refresh’ (periodically read the memory before data gets lost). SRAMs retain the value as long as the power is on

    The second part of the video shows a clever use of dynamic flip-flops to form a very efficient shift register (http://en.wikipedia.org/wiki/Shift_register) that requires about half as many transistors as the classic implementation.

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