Monday, October 13, 2014

LM35 Digital Remote Thermometer circuit and explanation

Digital Remote Thermometer circuit with very high accuracy temperature measurement features are set using the IC package numbers
Receiver Module Functional
LM35 (Linear temperature sensor IC) through a power amplifier and voltage change as a form of high frequency. To signal through the AC power cord.
For the receiver circuit and display module will receive the high frequency AC power cord and decode out to be the actual temperature figures with digital IC No. CD4553 Three-digit BCD Counter IC) and IC-CD4511 (BCD-to-7-Segment Latch / Decoder / Driver IC).
 Electronic Part List
Receiver Module
R1   100K 1/4W
C1,C2  47nF 400V
R2  1K 1/4W
C3,C7  1nF 63V
R3,R4,R6-R8  12K 1/4W
C4  10nF 63V
R5  47K 1/4W
C5,C6,C10  220nF 63V
R9-R15  470R 1/4W
C8  1000uF 25V
R16  680 1/4W
C9  100pF 63V
D1,D2,D5  1N4148
D3,D4  1N4002
D6-D8  Common-cathode 7-segment LED mini-displays
IC1  403
IC2   4518
IC3  78L12
IC4  4017
IC5  4553
IC6  4511
Q1 BC239C
Q2-Q4  BC327

L1  Primary (Connected to C1 & C2): 10 turns
Secondary: 100 turns
Wire diameter: 0.02mm. enameled
Plastic former with ferrite core. Outer diameter: 4mm.

T1 220V Primary, 12+12V Secondary 3VA Mains transforme
Remote Module Functional
    The frequency pulses from the wall and safely isolated by C1, C2 and L1 are amplified by Q1, diodes D1 and D2 of the peak limit his admission. The pulses are filtered by C5, IC1b square, divided by 10 in IC2B and sent for final countdown clock input of IC5. IC4 is the time base generator: it provides IC1b and reset pulses to the making and IC5 locks and opening time of IC5 at 1Hz frequency. It is powered by a 5Hz square wave obtained from the frequency 50Hz sector Retrieved from T1 secondary, squared and divided by 10 in IC1C IC2A. IC5 readers across the cathodes scenes Q2, Q3 and Q4 with a rate determined by frequency multiplexing C7. Readers also shows three anodes in parallel by the BCD to 7 segments decoder IC6. In summary, the input pulse power on, say, 2kHz frequency be divided by 10 and displayed as 20.0 ° C



Remote Circuit
Electronic Part List


Remote Module
R1,R3  100K 1/4W
C1  220nF 63V
R2  47R 1/4W
C2  10nF 63V
R4  5K 1/2W Trimmer Cermet
C3  1uF 63V
R5  12K 1/4W
C4,C6  1nF 63V
R6  10K 1/4W
C5  2n2 63V
R7  6K8 1/4W
C7,C8  47nF 400V
R8,R9  1K 1/4W
C9  1000uF 25V
D1  1N4148
IC1  LM35
D2,D3  1N4002
IC2  LM331
D4   Red LED
IC3  78L06
Q1  BC238
Q2 BD139

L1   Primary (Connected to Q2 Collector): 100 turns
Secondary: 10 turns
Wire diameter: 0.02mm. enameled
Plastic former with ferrite core. Outer diameter: 4mm.

T1   220V Primary, 12+12V Secondary 3VA Mains transformer

No comments:

Post a Comment