Temperature Lock With W1209 and Peltier As a Key

This is basic tutorial to make a unique lock which will open when hot and cold are applied on temperature controller w1209 sensors at the same time where one circuit will open relay when get hot and controller opens relay when get cold which is impossible without a Peltier. It can be further develop to make a unique key for every lock stacking the Peltries by adding more w1209 or using Arduino based circuits with multiple temperature sensors. It is just a basic concept where Peltier's ability to generate cold and hot surface at a same time, this can be used to make puzzles or more complex systems to be used professional products or making diy projects.

Please watch the video to understand the wiring and it is working.

2 x W1209 digital temperature controllers

1 x Peltier tec1-12706

1 x 12v DC power supply

1 x 12v Push pull solenoid

1 x 3.7v lithium battery

Hot glue

Wires

Cardboard

1 x Rubber band

2 x screws

1 x ziptie

1 x on off switch

Place the both w1209 on the cardboard by the help of hot glue, give it a 12v power supply and make the wiring according to the diagram.

The setting of the w1209 will be as one will work as hot and second as cold, need to press the set button for 4 second the P0 will appear set it to C and on the P1 set 1 , come out of setting and set the temperature to 30c it will work as cold which means if the temperature rises to 30 it will turn on the relay, now the second controller settings are P0 = H , P1 = 1 and temperature would be set to 27 it will work are hot which means it will turn on the relay if the temperature goes lower than 27 Celsius.

Doing this we created a 3 degree difference for both of them to turn on when applied hot and cold to there sensors allowing the 12v to the solenoid, I have set it very minimum but it can be set to -20 Celsius and 40 c as well.

Place the Peltier just below the circuits and mark it with pen, make two holes for the circuits sensors stick out and secure it with hot glue, the Peltier will be placed between the sensors.

Place the solenoid on the door structure made from the cardboard by placing the rubber band as it will keep open but stopped by the solenoid module as it is resting position is closed but will retract when voltage is applied it will let go the door.

Wrap the Peltier in a cardboard and make a switch on off connection with a 3.7v battery and wrapped the cardboard around it by the hot glue, as this is the smallest voltage it is getting so there will be no problem of it to get burn, we only need to turn it on for only upto 10 seconds for the Peltier to just get warm and cool which we needed.

When everything is placed correctly , now place the Peltier key in between the sensors then turn it on it will make the one sensor cool and other as warm triggering both the temperature controllers at once, the hot controller will release the 12v to cold one and cold controller will release it to the solenoid which will pull in it's body and let the door open.

It is a basic concept of trigging anything by just applying the different temperature at once which can be use in unique lock, puzzle or real life usable applications.

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Thanks for reading.