The buzzer module produces sound when a DC voltage is applied to the terminals. The buzzer is polarized and will only produce a sound when a positive voltage is applied to the positive terminal. When 2-3 V is applied, the buzzer will produce a sound with a frequency of 2300 ± 400 Hz. Compatible with all Modular Circuits kits.

This module contains a 0.33 F super capacitor. The capacitor is polarized, requiring that the positive side of a voltage source is applied to the positive terminal of the module. You can use this capacitor with a light bulb module to observe the light bulb dimming as the capacitor is discharged. Compatible with all Modular Circuits kits.

The diode module contains a PN junction diode that allows current to flow in only one direction. Current will flow when a negative voltage is applied to the side of the diode marked with the grey ring. The arrow on the diode symbol indicates the direction of conventional current. Compatible with all Modular Circuits kits.

The LED module contains a red LED. A 330 ohm resistor is connected in series to protect the LED from damage. The arrow on the LED symbol indicates the direction of conventional current. Compatible with all Modular Circuits kits.

The motor module contains a DC motor that will rotate when 1-3 V is applied to the terminals.  The motor spins in the opposite direction when a reverse polarity is applied to the terminals. The rotation speed of the motor increases as the voltage applied to the terminal increases. Compatible with all Modular Circuits kits.

The potentiometer module contains a 25 Ω potentiometer. The module is designed with a 2 W, 3 Ω resistor wired in series to protect the potentiometer from damage. Turn the knob of the potentiometer to vary the resistance. Compatible with all Modular Circuits kits.

The solar cell module outputs a voltage when light shines on the solar cell. The module works best when using the sun or an incandescent lamp as a light source. The solar cell has a rated voltage of 5 V and a rated current of 90 mA. Compatible with all Modular Circuits kits.

The straight module is used to connect various Modular Circuits components. Compatible with all Modular Circuits kits.

This module contains a single-pole double-throw (SPDT) switch. This switch is useful in circuits for charging and discharging a capacitor. Compatible with all Modular Circuits kits.