This circuit is a small “on-board” temperature recorder for RC models.
For those who practice this hobby know that the engine temperature is very important, not only for performance but also to ensure the smooth operation and durability of the engine.
It records the motor temperature of my helicopter in flight 2 times per second and stores it in memory.
A PCB tem apenas 51×30 centimetros.
The PCB size is only 51×30 centimeters.
Internally has a 16F88 microcontroller from Microchip that is the heart of the recorder and a 24LC512 eeprom memory also from Microchip divided into 4 blocks. This way I can make 4 independent data recordings, extract, delete and re-record individually.
Each memory block stores up to 15-minutes of data which for helicopter flights is more than enough.
To attach the sensor i used the arctic Alumina Silver paste. This paste, in addition to it’s fantastic properties, is also an adhesive making it ideal to glue and transfer the heat to the sensor.
The power source is from 2 AAA batteries 1.2V (rechargeable).The choice to use the two AAA batteries is mainly to reduce the weight to be transported by helicopter.
Since both rechargeable AAA batteries only provide 2.4V and because 5V is needed at least to achieve TTL levels used in RS232 output i included a small DC-DC converter providing 5V to the entire circuit.
It was installed between the engine fins and is in contact with the engine main body.