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Crank Wheel Pulser Software

The document discusses a software called the Crankshaft Timing Signal Wheel Simulator that simulates crankshaft and camshaft signals. It outputs the signals through a computer's sound card on the left and right channels. For higher voltage outputs suitable for hardware, amplified speakers or a transformer can be used to boost the voltage of the signals from the typical 3V output of a sound card. The document provides details on building a circuit using a transformer to step up the output voltage to 30V for the crank signal.

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Darel Dalmasso
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441 views3 pages

Crank Wheel Pulser Software

The document discusses a software called the Crankshaft Timing Signal Wheel Simulator that simulates crankshaft and camshaft signals. It outputs the signals through a computer's sound card on the left and right channels. For higher voltage outputs suitable for hardware, amplified speakers or a transformer can be used to boost the voltage of the signals from the typical 3V output of a sound card. The document provides details on building a circuit using a transformer to step up the output voltage to 30V for the crank signal.

Uploaded by

Darel Dalmasso
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
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Download as PDF, TXT or read online on Scribd
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Crank Wheel Pulser Software

The Crankshaft Timing Signal Wheel Simulator is software from Bowling and Grippo that
simulates the signal from a crank wheel. It does this by creating a sound file (.WAV) and
playing it back through a computer's sound card, on the 'left' channel. There is an optional
cam sync signal playable on the 'right' channel.

Hardware

A typical sound card by itself will only put out about 3 Volts (peak-to-peak) maximum
(you can always lower the voltage with the volume control). This may be enough for some
purposes, but you may want/need more. There are a couple of ways to increase the output
voltage of the signal to usable levels the signal:

1. Use amplified speakers (they will have an AC power adapter) that have a
headphone jack (often available for $20 or less, if you don't already have them).
These will boost the output to around 13 V (p-p) or more, and require no additional
hardware other than a headphone cable. Use the left channel for the crank signal, the
right channel for the cam signal. You will get the maximum output with both the
Windows volume and speaker volume set at their highest.
2. You can use a transformer to step up the output voltage (the following will give you
up to 30 Volts (p-p) on the crank signal). The variable reluctor (VR) output from the
sound card requires an 8 Ohm: 1K Ohm coupling transformer to drive the
MegaSquirt-II VR input circuit. A suitable transformer is Digi-Key 146KHM-ND
($12.89), however this is a 'non-stock' item. You can find them at Unicorn
Electronics. You might have better luck at your local electronics store (RadioShack,
etc.)

Both the VR transformer circuit and cam sync signal circuits are shown below:

The hardware for the VR output looks like this:


The red wire is the signal, the green wire is ground (on the left side of the
transformer). The thick black cable is a stereo jack pirated from an old set of
headphones.

The cam sync signal (if you use it) requires an external transistor driver circuit.

Wire the signal from the sound card to the low resistance side of the transformer, ~1
Ohm (it will be less than eight ohms, which refers to the impedance, rather than the
DC resistance), and the output to the high resistance (~50 Ohms DC) side of the
transformer.

You can build the transformer circuit on a small proto board, or solder the leads
directly to the transformer.

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