Traffic Lights

Hello again,

In this post I want to show you a project that I made while I was in 10th grade. It’s a set of four traffic lights, two for cars and the other two for pedestrians, located in the crossing of two streets. All of them are synchronized to work perfectly, even flashing when they are about to change.

The mechanism is a little bit difficult. It is a integrated circuit which uses a 555 timer circuit, a  HEF4020B 14-stage binary counter and an EEPROM memory. There are 10 outputs (10 LEDs, 3 in the car lights, and two for the pedestrian ones), all of which receive the state from the EEPROM, in which all the 64 configurations of each LED has been set.

To sum up, the 555 timer circuit generates a pulse which is slowed down by the binary counter and then, used in the EEPROM memory to change between the 64 different states. From the EEPROM the pulses are sent to the LEDs, all of which light accordingly.

In the integrated circuit can also be seen 6 LEDs which help to visualize the current state.

Here I leave you some images and videos to see it more clearly. You can find also the schematic of the circuit, the board and the Bill of Material. 

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Quiz Button Game

Hello everyone, how is it going?

Today I going to show you a project I developed in 9th grade, specifically on the second semester. The idea was to build a machine with buttons that could be used in a quiz game, so the first player to push his or her button would have the corresponding light switched on no matter if the other players had pressed any button afterwards. The requirements of the project were to build this mechanism for two players, instead of that, I developed it for 6, 3 teams of 2 members each.

To make this possible I created a electronic circuit using three double relays, so each button of the same colour could cancel the other two circuits, and switching on the LED of that team. I also added a switch to turn the device on and off and two boxes in the sides to store the decks of cards of the questions.

Here I leave you some pictures and a video to show it more clearly. You can also download the schematic and the Bill of Material.

Mechanical Lift

Hello everyone,
Today I’m gonna show you a project I did when I was in 9th grade.

It’s a lift powered by a electric engine connected to a pulley in whose axis is a threaded rod. So the threaded rod spins and the “lift” is attached to a nut, making it possible to go both up and down.

To change the spinning direction of the engine a manual commuter is used. In the top part 4 LEDs make an arrow that shows if the lift is going up or down.

Additionally, there are two switches at both ends of the way that the lift follows, stopping it when it has reached any of them. Here is a huge gallery of picks and a some videos to show it more clearly.