Showing posts with label NE555. Show all posts
Showing posts with label NE555. Show all posts
Friday, November 2, 2012
Mobile Incoming Call Indicator Circuit Diagram
this circuit can be used to escape from the nuisance of mobile phone rings
when you are at home. This circuit will give a visual indication if
placed near a mobile phone even if the ringer is deactivated.
When a call is coming to the mobile phone, the transmitter inside it becomes activated. The frequency of the transmitter is around 900MHz.The coil L1 picks up these oscillations by induction and feds it to the base of Q1. This makes the transistor Q1 activated.Since the Collector of Q1 is connected to the pin 2 of IC1 (NE555) , the IC1 is triggered to make the LED connected at its output pin (pin 3) to blink. The blinking of the LED is the indication of incoming call.
Notes:
Continue Reading here[...]
When a call is coming to the mobile phone, the transmitter inside it becomes activated. The frequency of the transmitter is around 900MHz.The coil L1 picks up these oscillations by induction and feds it to the base of Q1. This makes the transistor Q1 activated.Since the Collector of Q1 is connected to the pin 2 of IC1 (NE555) , the IC1 is triggered to make the LED connected at its output pin (pin 3) to blink. The blinking of the LED is the indication of incoming call.
Notes:
- The coil L1 can be made by making 150 turns of 36 SWG enameled copper wire on a 5mm dia plastic former.Or you can purchase a 10 uH coil from shop if available.
- The circuit can be powered from a 6V battery.
- Assemble the circuit on a good quality PCB.
- C1 & C3 are to be polyester capacitors.
- The electrolytic capacitor C2 must be rated 10V.
4017 LED Knight Rider Running Light Circuit Diagram
In this 4017 Knight Rider circuit, the 555 timer is
wired as an oscillator. It can be adjusted to give the desired speed
for the display. The output of the 555 is directly connected to the
input of a Johnson Counter (CD 4017).
Continue Reading here[...]
The
input of the counter is called the CLOCK line. The 10 outputs become
active, one at a time, on the rising edge of the waveform from the 555. Each output can deliver about 20mA but a LED should not be connected to the output without a current-limiting resistor (220Ω in the circuit above).
The
first 6 outputs of the chip are connected directly to the 6 LEDs and
these “move” across the display. The next 4 outputs move the effect in
the opposite direction and the cycle repeats. The animation above shows
how the effect appears on the display. Using six LEDs,
the display can be placed in the front of a model car to give a very
realistic effect. The outputs can be taken to driver transistors to
produce a larger version of the display.
Digital Object Counter using LDR and digital IC 7490
This is the simple circuit on Hobby Electronics. In this circuit three modules are used in object counter. 555 timer are used as a monostable mode and astable mode. The other is counter module.
In this circuit 555 timer configured as a monostable mode, is a simple automatic dark sensor circuit that gives output when light falling is blocked on LDR. Pin 3 of monostable circuit has been connected to pin 4 of astable timer. When monostable circuit generates output, astable mode timer starts giving pulses to the counter module. Frequency for counter module is set up using R4, R3 and C2. 
Continue Reading here[...]
7490acts as a decade counter and 7447 uses the output of 7490
to display numbers on seven segment display. This circuit counts from 0
to 9. You can count 0 to 100 modifying counter module circuit. Just
adding few components as well as two counter ic, two display driver and two display. For count 0 to 100, comments on the comments box. You will get complete circuit.
The output will be: If you block light falling on LDR, the number on seven segment display will increase.
Wednesday, June 15, 2011
Remote Control Using the NE 555 and LM 567
Remote control circuit consists of two parts, one is transmitter and the other is receiver. A simple diagram is schematic remote control. The transmitter circuit’s transmitter IC is controlled by NE555. Receiver circuit works by the signal emitted frequency which is emitted by that transmitter circuit. Transmitted signal frequency must be equal to the frequency decoder of the receiver circuit. The NE 555 generated frequency is same that receive frequency of IC LM 567.
The output frequency of the transmitter circuit is f,
f = 1.44/(Ra+2Rb)C
f = 1 / (1.1 xR1xC1)
This frequency depends on the value of R1 and C1.
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