From f9eb6b86d28020d9292219573445dabb6b6928b5 Mon Sep 17 00:00:00 2001 From: jaseg Date: Sun, 13 May 2018 18:02:25 +0200 Subject: Export drafts --- docs/posts/zeus-hammer/index.html | 117 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 docs/posts/zeus-hammer/index.html (limited to 'docs/posts/zeus-hammer') diff --git a/docs/posts/zeus-hammer/index.html b/docs/posts/zeus-hammer/index.html new file mode 100644 index 0000000..4d3e872 --- /dev/null +++ b/docs/posts/zeus-hammer/index.html @@ -0,0 +1,117 @@ + + + + + + Zeus Hammer | jaseg.net + + + +
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Zeus Hammer

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2018/05/03

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In case you were having an inferiority complex because your friends' IBM Model M keyboards are so much louder than the +shitty rubber dome freebie you got with your pc... Here's the solution: Zeus Hammer, a simple typing cadence enhancer +for PS/2 keyboards.

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The connects to the keyboard's PS/2 clock line and briefly actuates a large solenoid on each key press. An interesting +fact about PS/2 is that the clock line is only active as long as either the host computer or the input device actually +want to send data. In case of a keyboard that's the case when a key is pressed or when the host changes the keyboard's +LED state, otherwise the clock line is silent. We ignore the LED activity for now as it's generally coupled to key +presses. By just triggering an NE555 configured as astable flipflop we can stretch each train of clock pulses to a +pulse a few tens of milliseconds long that is enough to actuate the solenoid.

+/images/zeus_hammer_schematic.jpg +

Since PS/2 sends each key press and key release separately this circuit will pulse twice per keystroke. It would be +possible to ignore one of them but I figure the added noise just adds to the experience.

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Built on a breadboard, the circuit looks like this.

+/images/zeus_hammer_breadboard.jpg +

The completed system looks like this.

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Since my solenoid did not have a tensioning spring I used a rubber band and some vinyl tape to make an adjustable +tensioner. The small orange USB hub serves as an end-stop because I had nothing else of the right shape. The sound and +resonance of the thing can be adjusted to taste by moving the end stop, adjusting the tensioning rubber and tuning the +excitation duration using the potentiometer. My particular solenoid was a bit slow so I added some pieces of circuit +board as shims between the plunger and the case to limit the plunger's travel inside the solenoid core. Here is another +video of the thing in action in which I tune and de-tune the mechanical resonance using the potentiometer.

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+ + + + + -- cgit