Thursday, 2 September 2010
heres a diagram explaining how the various signals are routed around the system. the synth is patched into two video encoders, which are both synchronised to the sync pulse generator which also supplies sync to everything else that needs it, like the camera. the outputs of the two encoders are fed into the main and camera inputs of the ave3. from there they go to a phillips line selector, a bit of test equipment that generates a signal suitable for an ordinary oscilloscope, and that also has positive 5 volt triggers for the horizontal and vertical timings. (more about them in a sec.) the output of the phillips goes to a hitachi scope, and the bridged input is fed of to a hitachi waveform monitor. you can point the camera at these and it looks quite cool. a further bridging input is fed to the video monitor.
the five volt sync pulses from the philips are further processed by a box i built that contains a couple of comparators with variable thresholds from +12 to -12 volts. there are switches to change the comparator from inverting to non inverting so you can process pretty much any analog sync waveform into a usable waveform for the oscillators to sync to. (negative going pulses from some random positive value to about minus 12 volts in the case of my oscs.)
the above diagram and description is a bit crude so ill be amending it as time progresses.