# The rear lights of a car are to be controlled by digital logic

#### Vishistv

Joined Feb 20, 2017
1
The rear lights of a car are to be controlled by digital logic. There is a single lamp in each of the rear lights.

The inputs are:
• -LT left turn switch — causes blinking of left side lamp
• -RT right turn switch — causes blinking of right side lamp
• -EM emergency flasher switch — causes blinking of both lamps
• -BR brake applied switch — causes both lamps to be on
• -BL blinking signal with 1 Hz frequency
The outputs are:
• -LR power control for left rear lamp
• -RR power control for right rear lamp
Implement each function LR (BL, BR, EM, LT) and RR (BL, BR, EM, RT) with a 4-to-16-line decoder and external OR gates.

#### MrAl

Joined Jun 17, 2014
7,849
Hi,

So what did you try first? You normally have to show some work first in this section.

#### crutschow

Joined Mar 14, 2008
25,702
You have not asked for what you want (other than the obvious for us to solve the problem for you).
This is a Homework Help, not Homework Do forum.

What's your approach to solving the problem?
Have you studied the 4-to-16-line decoder to understand how it works?

#### RBR1317

Joined Nov 13, 2010
575
Here is an example of using a decoder to solve the brake light problem; however, the design parameters are far outside the original instructions which require use of two 4-to-16 line decoders plus some external OR gates. This solution uses a single 3-to-8 line decoder plus some OR gates. Logisim circuit file attached for anyone who may want to run the simulation.

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