Showing posts with label indicator. Show all posts
Showing posts with label indicator. Show all posts

Thursday, November 13, 2014

Automatic car parking indicator using Microcontroller Description Conventionally car parking systems does not have any intelligent monitoring syste


 Conventionally, car parking systems does not have any intelligent monitoring system. Parking lots are monitored by human beings. All vehicles enter into the parking and waste time for searching for parking slot. Sometimes it creates blockage. Condition become worse when there are multiple parking lanes and each lane have multiple parking slots.

Use of automated system for car parking monitoring will reduce the human efforts. Display unit is installed on entrance of parking lot which will show LEDs for all Parking slot and for all parking lanes. Empty slot will be indicated by glowing the respective LED.


We have used Infra Red transmitters and Receivers for each parking slot. The IR Receivers are connected to AVR microcontroller. IR rays are obstructed when a car is parked in any parking slot. Thus AVR will come to know that which slot is empty and which slot is full. We have chosen IR module instead of RF module because we want a receiver having line of sight communication with the transmitter. But RF does not require line of sight communication. And in case of LDR, there is scope for false triggering due to sunlight or headlight of car. So considering all these points we have finalized to use IR module. For transmitter section we are going to use IR LEDs driven by a 555 timer IC. Timer IC will generate a frequency of 38 KHz, which will be given to IR LED
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Thursday, October 23, 2014

Very Simple Peak Indicator Circuit

 This series is made to indicate that the amplifier has been given the maximum signal, the amplifier has the ability to be at its peak. if the lights do not mean the signal-plus volume. the way it works is the LED lights will light up when given a signal that more than 1.8 volts, the average amplifier will be saturated (maximum) if the signal was given more than this. 

The circuit is very simple to the point that we forget that making a series of peak signal can in this way. circuit is mounted on the output tone control IC, master mixer output, or input power amplifier. This series does not impose on other circuits. survived the experiment!
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Wednesday, October 15, 2014

Under voltage Indicator for Battery Equipment Circuit Diagram

This is the simple Under voltage Indicator for Battery Equipment Circuit Diagram. Due to the low duty cycle of flashing LED, the average current drain is 1 mA or less. The NE555 will trigger the LED on when the monitored voltage falls to 12 volts.The ratio of Rl to R2 only needs to he changed if it is desired to change the voltage point at which the LED is triggered.


Under voltage Indicator for Battery Equipment Circuit Diagram

Under

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Friday, September 12, 2014

Battery Charger Indicator Circuit


Most of you asked about a Battery Charger Indicator Circuit.This schema indicates weather battery is charged or not.This schema avoid the over charge of batteries purple LED will indicate the battery is charging.After charging purple LED is off.



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Monday, September 8, 2014

Overload Indicator TL072

The overload indicator consists of a window comparator that measures the magnitude of an a.f. signal. Two of the opamps contained in an TL072 are supplied with a reference voltage by potential divider R1-R2-R3-P1. The outputs of the opamps drive T1 via diodes D1 end D2 (that function as half-wave rectifier), which in turn actuates D3. Network R5-R6-C2 ensures that the LED lights even during short signal peaks. Capacitor C2 is charged fairly rapidly via D1 (or D2)and R5, after which it discharges slowly via R6, R9 and the base-emitter junction of T1. Capacitor C1 also contributes to the longer lighting of the LED.
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     When the level of the signal at the input is high enough, IC1a, is toggled by the positive half periods of the signal and IC1b by the negative halves. In this way, a peak above the maximum level will be indicated even when the signal is asymmetrical. Because of the symmetrical power supply and design of the indicator, the reference voltage for both opamps can be set with one potentiometer. The circuit draws a current of 5-6 mA when the LED is off. When an overload peak is indicated, the LED draws an additional 20 mA. With values as shown, the reference voltage can be set roughly between 0.9 V and 5.5 V.
The circuit can be connected to the output of a power amplifier, but potential divider R7-R8 then needs to be adapted and protected by diodes to the supply lines.



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Thursday, September 4, 2014

Water Level Indicator Circuit

Simple, two-wire, remote monitoring unit, Three-LED level display, 9V battery powered
The whole project was developed on a friends request. Its purpose was to remotely monitor the water-level in a metal tank located in the attic by means of a very simple control unit placed in the kitchen, some floors below.

Mains requirements were:
  1. No separate supply for the remote schema
  2. Main and remote units connected by a thin two-wire cable
  3. Simple LED display for the main unit
  4. Battery operation to avoid problems related to mains supply and water proximity
  5. As the schema was battery operated a low current consumption was obviously welcomed
The very small remote unit is placed near the tank and measures the water level in three ranges by means of two steel rods. Each range will cover one third of the tank capacity:
  • Almost empty - signaled by means of a red LED (D3) in the control unit display
  • About half-level - signaled by means of a yellow LED (D2) in the control unit display
  • Almost full - signaled by means of a green LED (D1) in the control unit displa
Circuit diagram:
Water
Water-level Indicator Circuit Diagram

Circuit operation:
When the water-level is below the steel rods, no contact is occurring from the metal can and the rods, which are supported by a small insulated (wooden) board. The small schema built around IC1 draws no current and therefore no voltage drop is generated across R5. IC2A, IC2B and Q1 are wired as a window comparator and, as there is zero voltage at input pins #2 and #5, D3 will illuminate. When the water comes in contact with the first rod, pin #13 of IC1 will go high, as its input pins #9 to #12 were shorted to negative by means of the water contact. Therefore, R4 will be connected across the full supply voltage and the remote schema will draw a current of about 9mA. 

This current will cause a voltage drop of about 0.9V across R5 and the window comparator will detect this voltage and will change its state, switching off D3 and illuminating D2. When the water will reach the second rod, also pin #1 of IC1 will go high for the same reason explained above. Now either R3 and R4 will be connected across the full supply voltage and the total current drawing of the remote schema will be about 18mA. The voltage drop across R5 will be now about 1.8V and the window comparator will switch off D2 and will drive D1. The battery will last very long because the schema will be mostly in the off state. Current is needed only for a few seconds when P1 is pushed to check the water-level and one of the LEDs illuminates.
Parts:
R1 = 15K 1/4W Resistors
R2 = 15K 1/4W Resistors
R3 = 1K 1/4W Resistors
R4 = 1K 1/4W Resistors
R5 = 100R 1/4W Resistor
R6 = 47K 1/4W Resistor
R7 = 3.3K 1/4W Resistors
R8 = 3.3K 1/4W Resistors
R9 = 2.7K 1/4W Resistors
R10 = 15K 1/4W Resistors
R12 = 15K 1/4W Resistors
R13 = 3.3K 1/4W Resistors
R14 = 2.7K 1/4W Resistors
R15 = 2.7K 1/4W Resistors
D1 = 3mm Green LED
D2 = 3mm Yellow LED
D3 = 3mm Red LED
C1 = 470nF 63V Polyester or Ceramic Capacitor
J1 = Two ways output sockets
J2 = Two ways output sockets
P1 = SPST pushbutton
B1 = 9V PP3 Battery
Q1 = BC547 45V 100mA NPN Transistor
IC1 = 4012 Dual 4 input NAND gate IC
IC2 = LM393 Dual Comparator IC
Two steel rods of appropriate length
Notes:
  • The two steel rods must be supported by a small insulated (wooden) board
  • IC1 and R1-R4 are mounted on a small board placed near or on the steel rods support
  • The two-wire cable connecting the remote schema board to the main control board, i.e. J1 to J2, can be of any size and type (preferably thin for obvious reasons). It can be very long, if necessary.
  • The schema can be used also with non-metal tanks, provided a third steel rod having the height of the tank will be added and connected to pin #7 of IC1, R3, R4 and J1.
  • The 4012 chip was chosen because it contains two gates and was at hand, but you can use two of the gates contained into 4001, 4011, 4093, 4049, 4069 etc. chips, provided all inputs of each gate are tied together and all inputs of unused gates are connected to the positive rail, leaving output pins open.
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Thursday, August 14, 2014

Telephone Tapping Indicator

This simple schema can indicate a misuse or tapping of Telephone line through a loud alarm. The schema is too simple and can be easily assembled on a common PCB. Line voltage of Telephone lines is around 48 volts DC in the On hook state. When the handset is lifted, this voltage reduces to 12 volt DC. This change in voltage level is used to activate the schema.When the switch S1 is closed, schema becomes active and the telephone enters into the armed state.

Telephone Tapping Indicator Circuit diagram

The high volt DC from the telephone line passes through R1 and VR1 and bias T1 into conduction. As a result, the collector of T1 goes to ground potential to inhibit T2 from conduction. Buzzer and LED thus remain off. When the handset is lifted, the DC voltage from the telephone lines drops to 12 volts. This turns off T1 and T2 conducts. Buzzer beeps and LED lights indicating that the telephone is using.
 
Setting
Connect the schema to Telephone lines using a telephone plug. The free socket of the telephone or Caller ID can be used. Close S1 and adjust VR1 till buzzer stops beeping. Lift the handset. Buzzer should sound. Otherwise, just adjust VR1 till buzzer beeps.
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Saturday, August 9, 2014

Network Voltage Indicator Wiring diagram Schematic

Using this schematic is created a network voltage indicator electronic schema. If the input voltage is gift across the network, the optocoupler transistor is open, T1 is blocked and controlled rectifier, Th1, is in a very state of conduction. Since each terminals of the piezoelectric buzzer is at identical potential, buzzer is off. If voltage disappears, the transistor T1 enters the conduction and therefore makes the terminal of buzzer to be placed on the bottom (maintains thyristor conduction state).



during this state of affairs, theres a sufficiently giant potential distinction across the buzzer and D5s to see that these 2 components to point AC power loss, each audible and visual. By pressing the reset button current is interrupted by Th1, therefore thyristor enter in blocking state and therefore the different terminal of the buzzer is connected to ground.
Source by : Streampowers
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Friday, August 8, 2014

Supply Voltage Indicator

Supply Voltage Indicator Circuit Diagram. A novel supply voltage monitor which uses a LED to show the status of a power supply.This simple and slightly odd schema can clearly show the level of the supply voltage (in a larger device): as long as the indicator has good 12 volts at its input, LED1 gives steady, uninterrupted (for the naked eye) yellow light. If the input voltage falls below 11 V, LED1 will start to blink and the blinking will just get slower and slower if the voltage drops further - giving very clear and intuitive representation of the supplys status. The blinking will stop and LED1 will finally go out at a little below 9 volts. On the other hand, if the input voltage rises to 13 V, LED2 will start to glow, getting at almost full power at 14 V. The characteristic voltages can be adjusted primarily by adjusting the values of R1 and R4. The base-emitter diode of T2 basically just stands in for a zener diode.

Supply Voltage Indicator Circuit Diagram
Supply_Voltage_Indicator_Circuit Diagram
Supply Voltage Indicator Circuit Diagram

The emitter-collector path of T1 is inversely polarized and if the input voltage is high enough - T1 will cause oscillations and the frequency will be proportional to the input voltage. The relaxation oscillator ceases cycling when the input voltage gets so low that it no longer can cause breakdown along the emitter-collector path. Not all small NPN transistors show this kind of behavior when inversely polarized in a similar manner, but many do. BC337-40 can start oscillations at a relatively low voltage, other types generally require a volt or two more. If experimenting, be careful not to punch a hole through the device under test: they oscillate at 9-12 V or not at all.

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