Bistable mode 555 timers, also called flip flops, hold their output (pin 3) either high or low depending on which input, trigger (pin 2) or reset (pin 4 ) was last given a low signal.
Assortment of commonly used integrated circuits (IC). I made a lot of videos with them
White version of the oscilloscope that I use in many of my recent videos.
- Trigger pin (called set pin in this circuit) getting a low signal sets the output high. That is unless the reset pin also has a low signal, in which case the output stays low.
- Reset pin with a low voltage sets the output low no matter what. After the switch is released the output stays low until there is a low signal to the trigger/set pin.
- Pull up resistors hold the set/reset inputs high (Vcc) until a direct connection to 0V is made. Don’t leave input pins floating, they will pick up weak electromagnetic signals that surround them.
- Output LED headed to ground lights up when the output is high. High output voltage is as close to the positive supply voltage that the 555 output can get to.
- Output LED headed to the positive supply (Vcc, 5V, etc.) lights when the output is low. Low 555 output is almost connecting directly the 0V/negative supply rail voltage.
Power supply I use in my videos.
555 timer bistable flip flop mode basic circuit with alternating LEDs electronics by electronzap
- 555 Timer IC The particulars of this integrated circuit covered on this page make a lot more sense after you study the basic circuits that follow.
- 555 timer bistable mode – Flip flip basic circuit
- 555 timer monostable mode – One shot
- 555 timer astable multivibrator mode – Flashing LEDs
- 555 timer schmitt trigger logic inverter – NOT gate
- 555 timer LDR controlled astable multivibrator mode LED flasher circuit
- 555 timer – Buzzer output – Astable multivibrator mode – Light dependent resistor LDR controlled circuit
- Electronic component appearance and schematics – Commonly used through hole versions
- Electronic circuit basics
- Voltage sources for electronics basics
- Multimeter measuring voltage
- Resistor component – Learning electronics resistors
- Light Emitting Diodes – Indicator LEDs
- LED circuit -Lighting a Light Emitting Diode
- Resistor limiting current – Ohms law
- Multimeter measuring current
- Wattage – Electrical Power unit
- Resistors connected in parallel
- Series resistors
- Voltage divider – Setting a fractional voltage
- Resistor color code
- Diode – Rectifier
- Trimpot – Trimmer potentiometer – Voltage divider – Variable resistor
- Capacitor component
- Capacitor RC time constant
- Voltage ramp Demonstrated using a capacitor.
- LM334 three terminal adjustable current source not a common component. I use for an easy current source in many circuits.
- Switch NOT logic gate – digital signal inverter
- Switch OR gate – LED circuit
- Switch AND gate – LED circuit
- Switch based NAND logic gate – LED demonstration circuit
Transistors will probably be the most challenging components to learn. Understanding them will help you understand all of electronics much better, and help you the most in being creative while designing your own circuits.
- NPN BJT switch circuit – Bipolar Junction Transistor – 2N3904
- PNP BJT switch – Bipolar Junction Transistor – 2N3906
- NPN BJT emitter follower circuit – transferring a voltage minus a diode drop
- PNP BJT emitter follower circuit – Transferring weak signal voltage with a diode voltage shift
- Bipolar Junction Transistor BJT voltage follower circuit improved to eliminate base emitter diode shift
- NPN BJT current source – Bipolar Junction Transistor – 2N3904
- PNP BJT current source – Bipolar Junction Transistor – 2N3906
- Schmitt trigger – NPN BJT
- Zener diode component – voltage reference – regulator
- Voltage doubler circuit fragment- Capacitor charge pump – Some V loss
- 7805 5V positive voltage regulator IC
- Battery voltage state of charge SOC – From fully charged to discharged
These pages are still being compiled.