TLC 272 PREAMPLIFIER

Tweet

here is the one good circuit what i found with sharp tone controller.for best performance use very smooth power supply for this circuit. the circuit shown here must duplicated to obtain a stereo preamplifier.

UP/DOWN FADING LED CIRCUITS

Tweet

These two circuits make a LED fade on and off. The first circuit charges a 100u and the transistor amplifies the current entering the 100u and delivers 100 times this value to the LED via the collector-emitter pins. The circuit needs 9v for operation since pin 2 of the 555 detects 2/3Vcc before changing the state of the output so we only have a maximum of 5.5v via a 220R resistor to illuminate the LED. The second circuit requires a very high value electrolytic to produce the same effect.

LM3909 LED flasher

Tweet

The LM3909 is an integrated circuit (IC) which will flash a light-emitting diode (LED). Using only two extra components and a battery, the circuit is cheap and has a very low current drain from a 1.5 V cell. The circuit can be used as a novelty flasher, an indicator for a dummy alarm bell box, or it could be attached to a torch so that it could be found easily in the dark!