Review: Temperature Controlled Fan System

 

The intended system/project ‘Temperature Controlled Fan System’ is generally used in electronic devices, project cabinets, with kits which produces unwanted heat due to varying load conditions during their normal operation.

Even though such unwanted heat reduction is done by many means, fitting fan and switch it On/Off spontaneously is one economical way. Note that even varying the cooling fans speed according to heat measured is also done with small modification [by applying the PWM technique!].

Table to show two approaches of same titled project or system
Module	Approach 1	Approach 2
Controller Module	ATmega8 IC	AT89C52 IC
ADC Module	On-chip Peripheral Of  ATmega8 IC	ADC0804 IC
Temperature Sensor Module	LM35 IC	LM35 IC
Display Module	Indicator LED	LCD Module
Driver Module	L293D Module	2N2222, 12V Relay
Load/Fan	DC Motor as Fan	Fan as load

 

 

 

 

 

 

The system or project works in two ways: Monitor temperature in its sensor vicinity; when monitored temperature crosses set threshold values switches ON fan.

Objective: Switch On/Off Fan when measured/sensed vicinity temperature crosses the set threshold value. It is not about varying the Fan speed according to the measured temperature value.

Approach 2 is having all modules in hardware form [outside the chip], and hence interfacing the modules with controlling module is learned well while designing the system. The Approach 1 is having ADC module inbuilt, and hence coding is needed to access it internally.

Approach 1:

• The system is built around ATmega8 IC which is having ADC [Analogue to Digital Converter] as on-chip peripheral.
• While coding, configuring ADC is needed as it is used to read vicinity temperature.
• Interfacing Temperature Sensor Module to Microcontroller is learn as under hardware interface technique [by referring Datasheet].
• Code is developed at the Microcontroller end to drive Driver Module so that it can switch On/Off the fan or load. As DC Motor is used as Load/Fan, L293D module is used as Driver Module and is controlled by code.
• The memory resident Microcontroller code compares sensed temperature reading with set threshold value and takes appropriate action.

Approach 2:

• The system is built around AT89C52 IC which is not having an ADC as on-chip peripheral, so external ADC Module is used.
• While coding, interfacing ADC is done as it is used to read vicinity temperature.
• Interfacing Temperature Sensor Module to ADC is learnt as under hardware interface technique [by referring Datasheets].
• Code is developed at the Microcontroller end to drive Driver Module so that it can switch On/Off the fan or load. Since relay is used as Driver Module, user can directly connect any fan/DC motor as load.
• The LCD Module [Liquid Crystal Display] is used to show sensed temperature value and action taken message to a user on its screen.
• The memory resident Microcontroller code compares sensed temperature reading with set threshold value and takes appropriate action.

Applications:

• Such system/project can be used to control temperature of monitoring room, device, or circuit boards [e.g. PCs mother board] etc.
• By employing PWM [Pules Width Modulation] technique user can vary the speed of Cooling Fan, instead of only making it On/Off.

Title: Microcontroller Based Temperature Controlled DC Fan System

Reference Links: electronicshub.org

-Temperature Controlled DC Fan using Microcontroller

-Temperature Controlled DC Fan (using 8051)

 

Keywords: Microcontroller, ATmega8, AT89c52, ADC 0804, L293D, LM35, LCD, Relay

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ProjectReview Tags: ProjectReview

 

…till next post, bye-bye & take care.