555 Timer Basics
This 8‑pin IC can generate accurate time delays or oscillations.
What is a 555 timer?
This type of signal has a continuous range of values.
What is an analog signal?
Binary uses only these two digits.
What are 0 and 1?
These are the three fundamental electrical quantities.
What are voltage, current, and resistance?
This component resists the flow of current.
What is a resistor?
In this 555 timer mode, frequency and duty cycle are set using two resistors and one capacitor.
What is oscillator (astable) mode?
These are the two voltage levels used in a digital signal.
What are logic HIGH and logic LOW?
The decimal number 26 is equal to this binary value.
What is 11010₂?
Ohm’s Law is expressed by this formula.
What is V = IR?
This component stores electrical charge and is measured in farads.
What is a capacitor?
This 555 timer pin discharges the capacitor during the LOW portion of the output cycle.
What is the discharge pin (pin 7)?
The number of cycles per second of a repeating signal is called this.
What is frequency?
The binary number 10010₂ equals this decimal value.
What is 18?
In a series circuit, this electrical quantity is the same through all components.
What is current?
DIP and SOIC are examples of this.
What are IC package styles?
This equation gives the LOW time of a 555 timer oscillator:
t = 0.693 × ___ × C
What is RB?
This is the percentage of time a digital signal remains HIGH during one period.
What is duty cycle?
In binary weighting, this bit position has a value of 16.
What is 2⁴ (bit‑4)?
In a parallel circuit, this quantity is the same across all branches.
What is voltage?
A good solder joint should appear smooth, bright, and this.
What is shiny?
If RA = RB, the duty cycle of a standard 555 oscillator will be greater than this value.
What is 50%?
An oscilloscope’s horizontal axis always represents this quantity.
What is time?
Convert 11010011₂ to decimal.
What is 211?
This law states that the sum of voltage drops in a loop equals the source voltage.
What is Kirchhoff’s Voltage Law (KVL)?
This class of fire extinguisher should be used for electrical fires.
What is Class C?