Using a 555 timer circuit and a few electronic components can be made very simple metronome. Timer 555 circuit is connected to circuit as a astabil multivibrator and produces regular pulses that can be heard in a speaker. Metronome pulse frequency can be adjusted with the 220k potentiometer. The circuit requires a supply voltage of 9 volts DC power supply( can be used and a battery). If is used a speaker with an impedance of 8 ohms must be connected a series resistance of 1 watt.
A very simple 555 timer circuit DC motor speed control electronic project can be designed using this circuit diagram. This 555 timer circuit DC motor speed control project is very simple and require few external electronic parts . Using this circuit you can control speed of a 6 volts DC motor, by simply rotate left or right the 50 k potentiometer.
The speed of a motor can be adjusted by this circuit, from 5% to 95%. The entire circuit must be powered from a simple 6 volts DC power supply .