The circuit can generate different signals like sine and square wave with wide band of frequencies.
It is based on ICL8038 Precision Waveform Generator/Voltage Controlled Oscillator.
The supply voltage for this circuit is a single Li-ion Battery with a protection circuit attached, and there is charging terminal on the PCB.
The ICL7660S voltage converter IC was not available, so we used the MT3608 Boost Converter in SEPIC inverting methodology to supply +9 and -9 volts.
Another MT3608 was used as a normal step-up circuit to supply the main voltage of 12 volts.
The design inspired by a Chinese kit with following schematic:
This circuit can be fabricated in home a printable file is attached in PCB folder.
The printer quality was poor so that the acid came through the ink and etched unwanted area 😅, but it was fixed and circuit works perfectly.
NOTE: The top connection are jumper wires.
