Chamber Room Using Thermocouple and Relay

Fajar Purnama
6 min readMar 8, 2020

1. Introduction

A chamber room in this experiment is known as an automation circuit. It’s designed to keep the room temperature at a certain degree. This chamber room is chosen as one of the training for automation.

Here we learned how to design our concept using ladder logic, and then realize the physical circuit by using a few automation devices. The purpose of this training is to introduce to few automation devices which are relay, contractor and thermal couple. We built an experimental chamber room based on the ladder diagram we designed.

2. Experiment Design

The chamber room how we wanted to work here is by using a heater to heat a room, when the room temperature is lower than the set temperature (cooler) the heater will be on to heat the room, but if it is higher (hotter) the heater will turn off. The heater will turn on again when the temperature drops.

Figure 1. Ladder diagram of chamber room.

Figure 1 shows the ladder diagram of chamber room we wanted to make. The concept is locking the room temperature.

a. When the button is pushed an electric current will flow to relay R1 (pin 13 to 14) and activate thermocouple (RTC) while R1 (pin 9 to 5) will lock the current even if the push button is off (the light will remain on). The left side is the positive node connected to the power supply while the right side connects to the ground. The numbers on Figure 1 are pins which will be explain later on.

b. The thermocouple will activate the Contractor and activates the heater.

c. The thermocouple will sense the room temperature and when it reaches the set temperature (heats), the thermocouple will switch off (cut the line).

d. Electric current will stop flowing to contractor hence shutting down the heater.

e. After a while the room temperature will drop (cools down) and again activating the thermocouple (let current flow) and activates the contractor with the heater.

f. The cycle will go on locking the room temperature.

The relay (R1) is set to lock the flow of electric current to the thermocouple since we’re using a push button. Without it the circuit will turn off after we release the push…

Fajar Purnama

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