My Circuit

This portable solar lantern circuit uses 6 volt/5 watt solar panels are now widely available. With the help of such a photo-voltaic panel we can construct an economical, simple but efficient and truly portable solar lantern unit. Next important component required is a high power (1watt) white LED module. When solar panel is well exposed to sunlight, about 9 volt dc available from the panel can be used to recharge a 4.8 volt /600 mAh rated Ni-Cd batterypack. Here red LED (D2) functions as a charging process indicator with the help of resistor R1. Resistor R2 regulates the charging current flow to near 150mA. Solar Lantern Circuit Schematic Assuming a 4-5 hour sunlit day, the solar panel (150mA current set by the charge controller resistor R2) will pump about 600 – 750 mAh into the battery pack. When power switch S1 is turned on, dc supply from the Ni-Cd battery pack is extended to the white LED (D3). Resistor R3 determines the LED current. Capacitor C1 works as a buffer. Note: After con...

The target of this project was the design of a small portable mixer supplied by a 9V PP3 battery, keeping high quality performance. The mixer is formed assembling three main modules that can be varied in number and/or disposition to suit everyone needs. The three main modules are: Input Amplifier Module: a low noise circuit equipped with a variable voltage-gain (10 - 100) preset, primarily intended as high quality microphone input, also suitable for low-level line input. Tone Control Module: a three-band (Bass, Middle, Treble) tone control circuit providing unity-gain when its controls are set to flat frequency response. It can be inserted after one or more Input Amplifier Modules and/or after the Main Mixer Amplifiers. Main Mixer Amplifier Module: a stereo circuit incorporating two virtual-earth mixers and showing the connection of one Main Fader and one Pan-Pot. The image below shows a Block diagram of the entire mixer featuring four Input Amplifier Modules followed by four in-out...