piezo(BELl) - a piezo buzzer is a type of electronic device that's used to produce a tone, alarm or sound. It's lightweight with a simple construction, and it's typically a low-cost product.

photoresistor - A photocell or photoresistor is a sensor that changes its resistance when light shines on it.

powersupply

seven segment display - The 7-segment display, also written as “seven segment display”, consists of seven LEDs (hence its name) arranged in a rectangular fashion as shown. Each of the seven LEDs is called a segment because when illuminated the segment forms part of a numerical digit (both Decimal and Hex) to be displayed.

555 timer - The basic 555 timer gets its name from the fact that there are three internally connected 5kΩ resistors which it uses to generate the two comparators reference voltages.

capacitor - A capacitor is a device that stores electrical energy in an electric field. It is a passive electronic component with two terminals. The effect of a capacitor is known as capacitance

polarized capacitor

potentiometer - A polarized ("polar") capacitor is a type of capacitor that have implicit polarity -- it can only be connected one way in a circuit. ... The negative lead is generally not shown on the schematic, but may be marked on the capacitor with a bar or "-" symbol. Polarized capacitors are generally electrolytics.

zener diode - A Zener diode is a silicon semiconductor device that permits current to flow in either a forward or reverse direction.

DC motor - Electric motors turn electricity into motion by using electromagnetic induction

coin cell 3v battery - a coin cell battery is a battery for retaining important system settings while a device is off. For instance, it provides power to the system clock so that the computer can remember what time it is after being powered off.

DIP switch SPSTx4 - A DIP switch is a manual electric switch that is packaged with others in a group in a standard dual in-line package (DIP).

temperature sensor - A temperature sensor is an electronic device that measures the temperature of its environment and converts the input data into electronic data to record, monitor, or signal temperature changes

741 operational amplifier - ts main purpose is to amplify (increase) a weak signal

NPN transistor - NPN transistors are mainly used in switching applications. Used in amplifying circuit applications.

Johnson decade counter - The standard 5-stage Johnson counter such as the commonly available CD4017 is generally used as a synchronous decade counter/divider circuit.

oscilloscope - an oscilloscope is a sophisticated diagnostic instrument that draws a graph of an electrical signal.

FUnction generator - A signal or function generator is a device that can produce various patterns of voltage at a variety of frequencies and amplitudes