EN
EN
BG
The proposed device can be used to make a "domestic incubator" thermostat, an aquarium thermoregulator, a floor heating thermostat, etc.
The draft solution provides a maintained fixed temperature in a closed vessel with an accuracy of ± 0.2 ° C.
In IC 723 there is an operational amplifier, an emitter repeater and a heat pump circuit.
The sensor is built with the D3, D4, D5 diodes and together with the resistors R3, R1, R2 and trimmer PR they form a bridge that can be controlled by the PR trimer so that the voltage of the differential input of the operational amplifier of the IC 723 in adjusting the desired the trigger temperature is 0.
The bridge is powered by a heat compensated voltage provided by terminal 6 of the IC.
Supporting 38 degrees. For the heater we will use a 40 W / 2x25 watt lamp. It also needs a thermometer to monitor the temperature. It should be borne in mind that when the trimer is rotated to R2, the temperature rises and R1 is lowered. Set the trimmer to 1/3 of R2 and monitor when the relay turns off the heater and also the temperature at the right time. The sample temperature is 40 degrees. We will have to rotate the trimer to R1 and again we will monitor at which temperature the relay will be switched off. After several settings with the trimmer we reach the desired temperature ...
The device can be powered in two ways:
Transformerless and transformerless, as a test re-regulation of the desired temperature, the transformer circuit must be used for safety purposes and then the transformer circuit can be applied.
To ensure trouble-free operation, use parallel battery power.
When working with 220VAC, observe the rules for high voltage operation.
