====== Circuit snippets ======
Some useful snippets for use in electronics projects.

===== Attenuverter =====
The gain figure is given by $$V_{out}=(2p-1)\cdot V_{in}$$ where $0\leq p\leq 1$ is the proportion of $V_{in}$ fed into the op-amp's noninverting input. Note also that the original schematic called for a 1k resistor between the op-amp's output and the out jack, but I forgot to include it in the figure. Such a resistor is ideal for limiting the output current in case the output is shorted. 

{{ ::attenuverter.png |}}

===== Gate-to-trigger converter =====
The resistor and capacitor form a differentiator with a 390 μs time constant (alternatively, a high-pass filter with $f_{3dB}\approx 408$ Hz). The diode between the comparator's noninverting input and ground provides a path for the negative spike out of the capacitor on the gate's falling edge (see Fig 1.43 in //The Art of Electronics//, 3ed). The diode on the output prevents the comparator from sinking current once its output is pulled to the negative rail. ((https://youtu.be/yz37Yz315eU?t=510. Cf. Fig 1.38, 1.39 in //The Art of Electronics//, 3ed, which does the opposite: it takes a short input pulse and produces a longer output pulse.))

{{ ::gate-to-trig.png?400 |}}