Motorola suggests this circuit in an 80's documentation. The circuit uses an inverter to produce a higher voltage for 9 V battery charge from a single cell.
Different delays for the rise time and fall time of the output signal when compared with the input...
This simple general-purpose transistor mixer was taken from an article in Electronics Now magazine in...
September 2017 - Würth Elektronik High Power Ultraviolet LEDs can be obtained from Mouser...