Step 1: Patreon
Step 2: Quick Summary of the 555 Timer
Step 3: Inventor and Manufacturer
Step 4: 555 Timer IC Pinout
•Ground reference voltage, low level (0 V)
Pin 2- (TRIG)
•The OUT pin goes high and a timing interval starts when this input falls below 1/2 of CTRL voltage (which is typically 1/3 VCC, CTRL being 2/3 VCC by default if CTRL is left open). More simply we can say that OUT will be high as long as the trigger is kept at low voltage. Output of the timer totally depends upon the amplitude of the external trigger voltage applied to this pin.
Pin 3- (OUT)
•This output is driven to approximately 1.7 V below +VCC, or to GND.
Pin 4- (RESET)
•A timing interval may be reset by driving this input to GND, but the timing does not begin again until RESET rises above approximately 0.7 volts. Overrides TRIG which overrides THR.
Pin 5- (CTRL )
•Provides "control" access to the internal voltage divider (by default, 2/3 VCC).
Pin 6- (THR)
•The timing (OUT high) interval ends when the voltage at THR ("threshold") is greater than that at CTRL (2/3 VCC if CTRL is open).
Pin 7- (DIS)
•Open collector output which may discharge a capacitor between intervals. In phase with output.
Pin 8- (VCC)
•Positive supply voltage, which is usually between 3 and 15 V depending on the variation.
Step 5: 555 Timer IC Modes
•Bistable mode or Schmitt trigger – the 555 can operate as a flip-flop, if the DIS pin is not connected and no capacitor is used. Uses include bounce-free latched switches.
•Monostable mode – in this mode, the 555 functions as a "one-shot" pulse generator. Applications include timers, missing pulse detection, bounce-free switches, touch switches, frequency divider, capacitance measurement, pulse-width modulation (PWM) and so on.
•Astable (free-running) mode – the 555 can operate as an electronic oscillator. Uses include LED and lamp flashers, pulse generation, logic clocks, tone generation, security alarms, pulse position modulation and so on. The 555 can be used as a simple ADC, converting an analog value to a pulse length (e.g., selecting a thermistor as timing resistor allows the use of the 555 in a temperature sensor and the period of the output pulse is determined by the temperature). The use of a microprocessor-based circuit can then convert the pulse period to temperature, linearize it and even provide calibration means.
Step 6: Specification for the 555 Timer
-Supply voltage (VCC) 4.5 to 15 V
-Supply current (VCC = +5 V) 3 to 6 mA
-Supply current (VCC = +15 V) 10 to 15 mA
-Output current (maximum) 200 mA
-Maximum Power dissipation 600 mW
-Power consumption (minimum operating)
-30 mW@5V, 225 mW@15V
-Operating temperature 0 to 75 °C