PIC based knight rider

 

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This circuit mimics the lights in knight rider's car. They flash one at a time chasing each other. This project uses an eight pin PIC12F675 or PIC12F683 micro-controller and five LED's. The circuit can be constructed on a strip-board, or a solder less breadboard.

 

Parts List
Resistors
R1 - R5	470R
Diodes
D1 - D5	LED
Capacitors
C1	100n or 100Kpf, ceramic-disc
Additional parts
IC1 - PIC 12F675 or 12F683
Common PCB

Description	Download link
Hex file for PIC 12F675 Ver.1.0.0	Download
Hex file for PIC 12F683 Ver.1.0.0	Download

 

PIC MCU based 5 LED Chaser

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LED Chaser is a simple project for beginners that can build using PIC micro-controller. This simple circuit functions as a 5 LED chaser. The heart of the LED chaser is the PIC micro-controller.  This can be either a PIC12F675 or PIC12F683 as software HEX code is provided for either device. The circuit can be constructed on a strip-board, or a solder less breadboard.

 

Parts List
Resistors
R1 - R5	470R
Diodes
D1 - D5	LED
Capacitors
C1	100n or 100Kpf, ceramic-disc
Additional parts
IC1 - PIC 12F675 or 12F683
Common PCB

Description	Download link
Hex file for PIC 12F675 Ver.1.0.0	Download
Hex file for PIC 12F683 Ver.1.0.0	Download

FM Telephone Transmitter

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The complete schematic of the telephone bug is shown in Fig.1. This circuit connects in parallel with the telephone line. Power for the circuit is full wave bridge rectified from the phone line by diodes D1 through D4. When the telephone receiver is on hook the voltage across the lines will be about 48 volts. At this voltage the Zener diode D5 will be in breakdown and the transistor Q1 will conduct. This makes the transistor Q2 OFF. When the receiver is off hook, the line voltage drops to about 12 volts. This makes the transistor Q1 OFF and subsequently the Q2 ON. The Q2 in switched ON condition will provide a DC path for the transistor Q3 in the FM transmitter section. The transmitter section is actually a small FM transmitter that can be turned to a vacant spot on your Fm radio. In the FM frequen­cy range, only a small antenna is needed to radiate a usable signal throughout a building. Its range is 50 to 100 feet with a 10cm antenna. The range can be increased by using a longer antenna. Transistor Q3 oscillate at a signal frequency which is determined by turned circuit L1, C6, VC and the inter electrode capacitance of the transistor. Capacitor C7 provides the need­ed positive feedback from the collector to the emitter for the circuit to oscillate. The audio signals applied to the base of Q3 cause collector current to vary at an audio rate and modulate the oscillator output. This type of modulation produces both FM and AM, but AM are rejected by the discriminator and limiters in the FM receiver and cause no problem. The collector current variations in turn vary the transistor’s output capacitance. This capacitance is part of the turned circuit and varies the frequen­cy of the output signal which is coupled to the antenna by C8.

Parts list
Transistors
Q1, Q2	BC547
Q3	BF494
Diodes
D1 - D4	1N4007
D5	18V Zener-diode
Resistors
R1	100K
R2,R6	22K
R3,R8	47K
R4	470K
R5	33K
R7	150K
R9	470R
Capacitors
C1, C3	10µ63V, electrolytic
C2, C4	100n or 100Kpf, ceramic-disc
C5	1n or 1Kpf, ceramic-disc
C6	33p, ceramic-disc
C7, C8	10p, ceramic-disc
Additional parts
L1- 4Turns, 22SWG Copper wire, 3mm air core
VC- 2-22pf, Trimmer Capacitor
ANT- 10 to 80cm copper wire
Common PCB