In the process of creating Amateur designs may require tools and equipment that are available it is often difficult. In such cases, comes to the aid of ingenuity, and craftsmen are doing everything they can with their hands. We will talk about how you can make a real recorder-thermoregulator from the old electrocardiograph type ЭК1Т-03M (Fig. 1).
This device may be required to measure and record the temperature of specific areas (details) for some time. Explain with an example. Collecting a powerful computer with your hands, you may face the problem of overheating of the processor. For cooling it will need a cooling system, which obviously eliminates the risk of failure of the “computer brain”. Well, if you own appropriate methods of calculation. And if not? You can, of course, immediately turn on the computer and “burn” the CPU or not? PI is unlikely you will meet the sad outcome of such an experiment… it is Much better to check the efficiency of the cooling system under model conditions by measuring the temperature rise of the radiator, which subsequently will be contacting the processor. Using the model heat source and thermoregulator, you will easily be able to choose the design parameters under which the processor will be guaranteed from overheating.
Fig. 1. Appearance:
1– button switch of the network; 2 – the indicator of inclusion of the network; 3 – a regulator of intensity pen; 4 – a plug for connection of the lead cable; 5 – the switch leads; 6 – regulator of the offset pen; 7 – button calibration; 8 – button speed switch; 9 – the button of calm; 10 – button; 11– switch sensitivity
Fig. 2. Roll thermal paper 50-meter provides 30 minutes of continuous recording of readings
It is useful to mention the principle of operation of a handmade thermoregulator. In the technique well-known methods of measuring temperature using thermoelectric thermometers (thermocouples). A thermocouple consists of two conductor of different material, the components of the shared electrical circuit (see Fig. 3). If the temperature of joints (junctions) of the thermocouple are not the same, then there is thermo-EMF and the circuit current flows. Thermal EMF is greater, the greater the temperature difference between the junctions. By connecting the thermocouple with recorder, get a device that allows you to record changes in temperature over time.