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Rangkaian Pengatur Temperatur Kipas angin

Rangkaian Pengatur Temperatur Kipas angin Parts:

P1_____________22K Linear Potentiometer (See Notes)

R1_____________15K @ 20°C n.t.c. Thermistor (See Notes)
R2____________100K 1/4W Resistor
R3,R6__________10K 1/4W Resistors
R4,R5__________22K 1/4W Resistors
R7____________100R 1/4W Resistor
R8____________470R 1/4W Resistor
R9_____________33K 4W Resistor

C1_____________10nF 63V Polyester Capacitor

D1________BZX79C18 18V 500mW Zener Diode
D2_________TIC106D 400V 5A SCR
D3-D6_______1N4007 1000V 1A Diodes

Q1,Q2________BC327 45V 800mA PNP Transistors
Q3___________BC337 45V 800mA NPN Transistor

SK1__________Female Mains socket

PL1__________Male Mains plug & cable

R3-R4 and P1-R1 are active as a Wheatstone arch in which R3-R4 accomplish a anchored two-thirds-supply "reference" voltage, P1-R1 accomplish a temperature-sensitive "variable" voltage, and Q1 is acclimated as a arch antithesis detector.

P1 is adapted so that the "reference" and "variable" voltages are according at a temperature aloof beneath the appropriate activate value, and beneath this action Q1 Base and Emitter are at according voltages and Q1 is cut off. When the R1 temperature goes aloft this "balance" amount the P1-R1 voltage avalanche beneath the "reference" value, so Q1 becomes advanced biased, pulse-charging C1.

This occurs because the accomplished ambit is supplied by a 100Hz half-wave voltage acquired from mains accumulation by agency of D3-D6 diode arch after a cutting capacitor and anchored to 18V by R9 and Zener diode D1. Therefore the 18V accumulation of the ambit is not accurate DC but has a rather trapezoidal shape. C1 provides a capricious phase-delay pulse-train accompanying to temperature and ancillary with the mains accumulation "zero voltage" point of anniversary bisected cycle, appropriately bearing basal switching RFI from the SCR. Q2 and Q3 anatomy a activate device, breeding a abbreviate beating acceptable to drive the SCR.

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