High - Low Temperature Indicator using LM35, 741 and LEDs

High – Low Temperature Indicator using LM35, 741 and LEDs

This High – Low Temperature Indicator shows us, by means of two LEDs, when the sensed temperature is above or below a set limit.

When the temperature is above the pre-set temperature level, LED D1 will light up and if it is below, LED D2 will light up.

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Temperature alarm circuit with Op. Amp.

Temperature alarm circuit with Op. Amp.

Temperature alarm circuit with 741 operational amplifier

This temperature alarm circuit with operational amplifier activates a relay when the temperature of the place to be controlled exceeds a set level. Useful for an oven temperature control or a cooling system

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Temperature gauge circuit using the LM324 IC

Temperature gauge circuit using the LM324 IC

Temperature gauge circuit using the LM324 IC

The temperature level is displayed using 4 LEDs: A green LED indicates that the temperature is OK.
Two yellow LEDs indicate that the temperature is higher than normal.
A red LED indicates that the temperature is very high

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