7555_step_mod.MOV

This is a simple step sequencer circuit.
One 7555 astable oscillator acts as a clock driving a 4 bit counter, which drives two 8 channel to 1 channel multiplexers. One multiplexer (mux) switches the LEDs on/off and the other passes 1 of 8 potentiometers to a second 7555 astable oscillator. other components are a voltage regulator and an audio amplifier to drive the speaker.

In this video the power is modulated by the audio. The power from the 9V battery is connected to a wire resting on the speaker. As the sound starts the power is quickly connected and disconnected. A mostly dead 9V acts as a capacitor to keep the circuit running for a short time when the charged battery is disconnected

Category:

Science & Technology

Tags:

• music
• technology
• electronics
• hacking
• noise