The 555-Timer Circuit


In a previous post I’ve talked about my new found hobby, that being electronic engineering. Been reading some really interesting literature about electronics lately and recently I came across the majestic 555-timer integrated circuit or the IC. What’s so cool about it it’s that his popularity makes it really cheap to purchase and easy to use. On the market there is also a dual version of this! It’s called the 556 and includes two independent 555’s. So! That being boring enough, let’s talk about what it does and what you can build using it! You’ll notice that the pins of the 555 are not dispersed in the same order as the actual electronic chip, so that you can easily recognize what function each one of them has and also majestically simplifying the drawing of an actual diagram, if you choose or need to create one! For the 555 to function properly it needs both electronic techniques: analog and digital, but you’ll find that it is actually categorized as a digital device circuit because of its output. At any given time, the output can be at “low state”, which is at 0v, or at “high state” which usually means the maximum that your power switch can provide, that being around 18v! There are a few common types of 555 outputs and their names will give you some hints about what they actually do! These are: outputs in the monostable mode (the 555 works as a “one-shot” circuit, for example :timers, bouncefree switches, touch switches, frequency dividers, pulse-width modulation or PWM etc.), astable mode outputs (or also called the free running mode, the timer works as an oscillator so think LEDs, flashing lamps, security alarms and pulse position modulation.), and last but not least the Schmitt trigger mode (the timer operates as a flip-flop, usually light switches and such), more information about this you can find on www.electroschematics.com/555-circuits/.