Transmitter ambit operation:
IC1 is a attention centigrade temperature sensor with a beeline achievement of 10mV/°C active IC2, a voltage-frequency converter. At its achievement pin (3), an ascribe of 10mV is adapted to 100Hz abundance pulses. Thus, for example, a temperature of 20°C is adapted by IC1 to 200mV and again by IC2 to 2KHz. Q1 is the disciplinarian of the ability achievement transistor Q2, accompanying to the mains accumulation by L1 and C7, C8.
Receiver ambit operation:
The abundance pulses advancing from mains accumulation and cautiously cloistral by C1, C2 & L1 are amplified by Q1; diodes D1 and D2 attached peaks at its input. Pulses are filtered by C5, boxlike by IC1B, disconnected by 10 in IC2B and beatific for the final calculation to the alarm ascribe of IC5.
IC4 is the time-base generator: it provides displace pulses for IC1B and IC5 and enables latches and gate-time of IC5 at 1Hz frequency. It is apprenticed by a 5Hz aboveboard beachcomber acquired from 50Hz mains abundance picked-up from T1 secondary, boxlike by IC1C and disconnected by 10 in IC2A.
IC5 drives the displays' cathodes via Q2, Q3 & Q4 at a multiplexing amount abundance anchored by C7. It drives additionally the 3 displays' paralleled anodes via the BCD-to-7 articulation decoder IC6.
Summing up, ascribe pulses from mains accumulation at, say, 2KHz frequency, are disconnected by 10 and displayed as 20.0°C.
IC1 is a attention centigrade temperature sensor with a beeline achievement of 10mV/°C active IC2, a voltage-frequency converter. At its achievement pin (3), an ascribe of 10mV is adapted to 100Hz abundance pulses. Thus, for example, a temperature of 20°C is adapted by IC1 to 200mV and again by IC2 to 2KHz. Q1 is the disciplinarian of the ability achievement transistor Q2, accompanying to the mains accumulation by L1 and C7, C8.
Transmitter parts:
R1,R3________100K 1/4W Resistors
R2___________47R 1/4W Resistor
R4____________5K 1/2W Trimmer Cermet
R5___________12K 1/4W Resistor
R6___________10K 1/4W Resistor
R7____________6K8 1/4W Resistor
R8,R9_________1K 1/4W Resistors
C1___________220nF 63V Polyester Capacitor
C2____________10nF 63V Polyester Capacitor
C3_____________1µF 63V Polyester Capacitor
C4,C6__________1nF 63V Polyester Capacitors
C5_____________2n2 63V Polyester Capacitor
C7,C8_________47nF 400V Polyester Capacitors
C9__________1000µF 25V Electrolytic Capacitor
D1__________1N4148 75V 150mA Diode
D2,D3_______1N4002 100V 1A Diodes
D4____________5mm. Red LED
IC1___________LM35 Linear temperature sensor IC
IC2__________LM331 Voltage-frequency converter IC
IC3__________78L06 6V 100mA Voltage regulator IC
Q1___________BC238 25V 100mA NPN Transistor
Q2___________BD139 80V 1.5A NPN Transistor
L1___________Primary (Connected to Q2 Collector): 100 turns
Secondary: 10 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
Receiver ambit operation:
The abundance pulses advancing from mains accumulation and cautiously cloistral by C1, C2 & L1 are amplified by Q1; diodes D1 and D2 attached peaks at its input. Pulses are filtered by C5, boxlike by IC1B, disconnected by 10 in IC2B and beatific for the final calculation to the alarm ascribe of IC5.
IC4 is the time-base generator: it provides displace pulses for IC1B and IC5 and enables latches and gate-time of IC5 at 1Hz frequency. It is apprenticed by a 5Hz aboveboard beachcomber acquired from 50Hz mains abundance picked-up from T1 secondary, boxlike by IC1C and disconnected by 10 in IC2A.
IC5 drives the displays' cathodes via Q2, Q3 & Q4 at a multiplexing amount abundance anchored by C7. It drives additionally the 3 displays' paralleled anodes via the BCD-to-7 articulation decoder IC6.
Summing up, ascribe pulses from mains accumulation at, say, 2KHz frequency, are disconnected by 10 and displayed as 20.0°C.
Receiver Parts:
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
