Temperature-Control | Electronic Project Circuits

Posts Tagged ‘Temperature-Control’

Scriptable Thermometer

You can build a variety of simple machines with the same hardware and a different script : a charting thermometer, a vending machine that dials your number when empty, a leavening cell… thermometer with 1Â°F (0.5C) resolution four switch inputs, four relay outputs only an handful of cheap parts graphic LCD display

Digital Remote Thermometer

Remote sensor sends data via mains supply
Temperature range: 00.0 to 99.9 °C

This circuit is intended for precision centigrade temperature measurement, with a transmitter section converting to frequency the sensor’s output voltage, which is proportional to the measured temperature. The output frequency bursts are conveyed into the mains supply cables. The receiver section counts the bursts coming from mains supply and shows the counting on three 7-segment LED displays. The least significant digit displays tenths of degree and then a 00.0 to 99.9°C range is obtained.

Part
R1__________100K 1/4W Resistor
R2____________1K 1/4W Resistor
R3,R4,R6-R8__12K 1/4W Resistors
R5___________47K 1/4W Resistor
R9-R15______470R 1/4W Resistors
R16_________680R 1/4W Resistor
C1,C2_________47nF 400V Polyester Capacitors
C3,C7__________1nF 63V Polyester Capacitors
C4____________10nF 63V Polyester Capacitor
C5,C6,C10____220nF 63V Polyester Capacitors
C8__________1000µF 25V Electrolytic Capacitor
C9___________100pF 63V Ceramic Capacitor
D1,D2,D5____1N4148 75V 150mA Diodes
D4,D4_______1N4002 100V 1A Diodes
D6-D8_______Common-cathode 7-segment LED mini-displays
IC1__________4093 Quad 2 input Schmitt NAND Gate IC
IC2__________4518 Dual BCD Up-Counter IC
IC3__________78L12 12V 100mA Voltage regulator IC
IC4__________4017 Decade Counter with 10 decoded outputs IC
IC5__________4553 Three-digit BCD Counter IC
IC6__________4511 BCD-to-7-Segment Latch/Decoder/Driver IC
Q1___________BC239C 25V 100mA NPN Transistor
Q2-Q4________BC327 45V 800mA PNP Transistors
L1___________Primary (Connected to C1 & C2): 10 turns
Secondary: 100 turns
Wire diameter: O.2mm. enameled
Plastic former with ferrite core. Outer diameter: 4mm.
T1___________220V Primary, 12+12V Secondary 3VA Mains transformer
PL1__________Male Mains plug & cable

Read more original source:http://www.redcircuits.com//Page11.htm

Constant Temperature by IC 741

This circuit was built to stabilize a radio frequency VFO (Variable Frequency Oscillator) for ham radio applications. The circuit has also been used to lower the drift of a Ramsey FM10a micropower FM transmitter.