OK, as a follow up to my discussions with Jeff we can propose the following design specification of the Light Bridge.
- Built in microphone and an additional 3,5mm stereo line input (mono internal) for modulating the light bridge. Two potentiometers for leveling microphone and external signal. Both signals are mixed and can be used simultaneously.
- Current driver for modulating one white LED inside the closed unit.
- Solar cell receiver with preamplifier working as a trans-impedance amplifier. LED will be operated linearly and symmetrically.
- Received signal from solar cell will be band pass filtered (300Hz .. 5KHz)
- LED clipping indicator to detect over-modulation
- 0 dBm audio jack output (stereo with mono signal) for recording.
- Adjustable headphone output (optional)
- External 12VDC power supply applied via standard DC power socket (Reverse polarity protected). Thus every standard 12VDC wall adapter should be suitable.
- Hum and EMI filter in DC power supply path
- Plastic Housing
User control elements and indicators
- Switch: Power ON/OFF
- Potentiometer: Mic Level
- Potentiometer: External audio input
- socket: 3,5mm line audio jack on front panel for headphones (optional)
- Potentiometer: headphone volume (optional)
- socket: 3,5mm line audio jack on backside for recording
- LED: ON/OFF
- LED: Signal clipping
@Lance/Jeff please confirm specification or require changes.