EnviroSynth is an analogue music synthesizer aimed at the renewable energy/educational electronics market. It consists of 2 Voltage Controlled Oscillators (VCOs), 1 four-channel Mixer, 1 Filter and 1 Voltage Controlled Amplifier (VCA). These are built entirely in analogue electronic hardware, and are based on a low power, intuitive and easily expandable and maintainable design. The music synthesizer also includes a keyboard input controller (KIC) and a Renewable Power Management System (RPMS) and these parts are implemented on a digital PIC microcontroller.
The VCO PCB consists of 2 Voltage Controlled Oscillators oriented one above the other; this PCB produces the original sawtooth and pulse waveforms that can then be mixed, shaped and/or amplified by the Mixer/VCA/Filter PCB. The 2 Hand Crank Dynamos and Solar PV Panel work together to supply power to the PCBs both directly and also via a rechargeable battery located at the back of the synthesizer.
The 2 VCOs are identical and are oriented side by side. The keyboard supplies a Control Voltage (CV) to one or both of the VCOs via the Vin ports; these CVs then determine the frequencies of the VCOs in combination with the Frequency Adjust potentiometers and the Frequency Range Selector rotary switches.
The mixer has 4 input channels so that any combination of the sawtooth waves and pulse waves from the VCO PCB can be mixed together. The filter allows the gain and Q of the various different parts of the waveforms to be individually altered, and the VCA amplifies the final electrical representation of the sound wave so that it can be listened to via headphones and/or a loudspeaker.