A Quick Post on Thermographic Imaging

We’re always having random thoughts at Circuithinking about products that can be the spark of an idea for doing things differently in the future and as of late we’ve all had a bit more spare time than usual to pursue other endeavours. We wanted to update you on some of the ideas we tinker with just for the hell of it.

One of the main thoughts we always come across is new and novel ways of doing sensing. We always take the usual form factors of sensing for granted: cameras, accelerometers, gyroscopes, magnetometers, thermocouples, the list goes on… They almost always typically end up being used in the exact same way every time. Not that this is without good reason because these implementations cover the vast majority of needs in the industry, but what about thinking outside the box? This is exactly what we wanted to do with Thermistors.

Thermistors are resistors whose resistance is dependent on temperature. In almost all cases, they’re used as single point measurement sensors to cheaply measure the temperature of a point. The emphasis is on single point. There aren’t many times in their implementation that you need more than a couple to do the job they usually fulfil. As an experiment, we wanted to change that. We decided to have a go at creating a Thermographic Panel.

To do this, we need an array of thermistors where each thermistor acts as a pixel in an image instead of just a single point measurement. This will enable us to reconstruct a full image of temperature by individually measuring the temperature of each thermistor as quickly as possible. Because we just wanted to toy around at first, we’ve settled for an 16×16 array for a 256 pixel image. We’re hardly pushing the boat out, but this should be enough to give us an indication of ability.

First quick step was to design a PCB. This isn’t something we can really prototype by hand so we need something custom made. The images below shows the final layouts.

Thermal Panel Top

Top of the Thermal Panel