Posts tagged ‘Thermistor’

Adding a Fan Controller to Topward 6603A

I did a review on Topward’s 6603A linear power supply last time. In my opinion, Topward 6000 series power supplies are really well made and offer exceptional performance. One minor annoyance though, as I mentioned, is that the two cooling fans are constantly on. This makes the otherwise great piece of lab equipment rather noisy, even when the load is light. Continue reading ‘Adding a Fan Controller to Topward 6603A’ »

Building a Wireless Temperature Sensor

I have built quite a few (1,2,3) temperature measurement circuits in the past, but none of those has remote sensing capability. So I decided to make a wireless temperature sensor so that temperature measurements can be made anywhere within the range of the transmitter and the receiver. Continue reading ‘Building a Wireless Temperature Sensor’ »

Thermistor Parameter Measurement — II

Last time I showed a simple circuit that can be used to measure unknown thermistor parameters. The circuit is basically just a power MOSFET using a voltage and duty cycle controlled PWM signal to drive the gate and thus generates a temperature reference which is measured by both the unknown thermistor and the precision temperature sensor LM335. By measuring the voltage drop across the thermistor at different temperatures, we can obtain the R-T curve of the thermistor and thus estimate the parameters that define the R-T curve using some known models. Continue reading ‘Thermistor Parameter Measurement — II’ »

Thermistor Parameter Measurement — I

Over the years, I have gathered quite a few NTC and PTC thermistors. But most of them are unmarked so it would be difficult to use them in an accurate way without knowing the parameters. So I decided to build a simple circuit that can be used to trace the temperature-resistance curve, and the parameters can then be estimated using the measured data points. Continue reading ‘Thermistor Parameter Measurement — I’ »