Ohms Law

Campana

Bill

Which is chiefly why I'm an engineer and not a fashion model.

John

That doesn't say much for the beauty of a single Larkin :-)

I picked up a cheapo signal generator chip from futurlec. It's an ICL8038, which is a VCO which can generate sine waves, triangle waves, and square waves between 0.1Hz and about 100kHz. Unfortunately, it's squirrly and sensitive to temperature. Also, adjusting the duty cycle seriously messes with the frequency. In order to fix this, I then wrote a program for a PIC that measures the squarewave frequency, and controls the VCO input using an SPI DAC I sampled from microchip. It's frequency is thus now as stable and accurate as the PIC clock, which is derived from a 20MHz crystal, even when changing the duty cycle.

To generate the lissajous patterns, I set up the 3011B to output a 500 Hz signal on the X channel, and use the ICL8038 on the Y channel of my scope. I then vary the frequency up or down using simple controls to the PIC. I use my sears multimeter, which has a 4.5 digit frequency mode, to view the frequency of the PIC. It would be easy to build an LCD display for the thing, but the multimeter works well enough.

A whole bunch is what's left over after a product is retired.

A shit load is all those custom parts that required a lifetime buy, and the project was canceled right after the parts were delivered.

Sounds like a good application for a couple DDS chips and low pass filters. :)