Schematic of car backseat tray

To operate automatic system driving circuit is needed . first of all arrange following parts .

  • Four relays .
  • Two push buttons
  • one click button
  • DC supply 
electrical circuit of car backseat tray table
schematics of car tray system
connect All parts as shown in above diagram.

Connect motor while table is fully opened and switch two is pressed . shown under the top in 3d view of car tray table and second from top to bottom in schematic.

  • Connect n/c pin of relay 2 to positive and n/c pin of relay 3 to negative.
  • Connect n/o pin of rely 2 to negative and n/o pin of relay 3 to positive.
  • Output from common pins of both relays is connected to dc geared motor.
Above connections will reverse the polarity of both output when click switch is operated and in return reverse the direction of rotation of motor. when click switch is opened both outputs to the dc motor are from n/c pins of relays. motor will rotate until switch 3 is pushed down and relay 4 is operated making n/o pin positive which will operate relay 3. now both terminals of dc motor are at 12 volts. Since there is no potential difference motor will stop.

When click switch is pressed down relay two will be operated too making other terminal negative motor will rotate in opposite direction . switch 3 will be released as table top rotate away making no difference on rotation as both relays are operated by click switch too. Rotation will continue until switch 2 is pressed down which will operate relay 1 making it open. and relay 3 will be also in off position i.e common pin is connected to n/c pin making dc motor at same potential and stop rotation.

electrical circuit of car backseat tray table
schematic using diode
  • You can add diodes between relays to control flow of current.
  • Use resistors to limit current flow in coils of relays.

RL1,RL2,RL3,RL4 = relay 1,relay 2, relay 3, relay 4.
battery = dc supply from car.


next post will be similar operation using micro-controller and centralized (more than one car table trays.)


Comments

Popular posts from this blog

Car Backseat Table System using PIC Micro-controller

Car backseat tray table mechanical assembly

Controlling servo with pic16f1789 for car backseat table