Battery Indicator schematic diagram

This circuit diagramc shows a simple battery level indicator.In general, in mobile phones, the battery levels is displayed in dot or bar style.This helps you to effortlessly acknowledge the battery level.

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Signals when an on-circuit battery is exhausted 5V to 12V operating voltage

A Battery-status Indicator circuit can be useful, mainly to monitor portable Test-gear instruments and similar devices. LED D1 flashes to attire the users attention, signaling that the circuit is running, so it will not be left on by mistake. The circuit generates about two LED flashes per second, but the mean current drawing will be about 200µA. Transistors Q1 and Q2 are wired as an uncommon complementary astable multivibrator: both are off 99% of the time, saturating only when the LED illuminates, thus contributing to keep very low current consumption. 

Circuit diagram :

Flashing-LED Battery-status Indicator Circuit Diagram

The circuit will work with battery supply voltages in the 5 - 12V range and the LED flashing can be stopped at the desired battery voltage (comprised in the 4.8 - 9V value) by adjusting Trimmer R4. This range can be modified by changing R3 and/or R4 value slightly.

When the battery voltage approaches the exhausting value, the LED flashing frequency will fall suddenly to alert the user. Obviously, when the battery voltage has fallen below this value, the LED will remain permanently off. To keep stable the exhausting voltage value, diode D1 was added to compensate Q1 Base-Emitter junction changes in temperature. The use of a Schottky-barrier device (e.g. BAT46, 1N5819 and the like) for D1 is mandatory: the circuit will not work if a common silicon diode like the 1N4148 is used in its place.

Parts :

R1,R7__________220R  1/4W Resistors
R2_____________120K  1/4W Resistor
R3_______________5K6 1/4W Resistor
R4_______________5K  1/2W Trimmer Cermet or Carbon
R5______________33K  1/4W Resistor
R6_____________680K  1/4W Resistor
R8_____________100K  1/4W Resistor
R9_____________180R  1/4W Resistor
C1,C2____________4µ7  25V Electrolytic Capacitors
D1____________BAT46  100V 150mA Schottky-barrier Diode
D2______________LED  Red 5mm.
Q1____________BC547   45V 100mA NPN Transistor
Q2____________BC557   45V 100mA PNP Transistor
B1_______________5V to 12V Battery supply
Notes :

• Mean current drawing of the circuit can be reduced further on by raising R1, R7 and R9 values. 

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Indicator Circuit Diagram for Model Railway System

1. A ninth reed contact is Htted at the end of the block, to enable turning off the indication for the relevant length of the track. The circuit is composed of 8 set-reset (S-R) bistables, which drive a LED each.
2. This section indication system may be a just the thing you have been looking for when you own a fairly large model railway with tunnels and tracks at several levels, and are sometimes at a loss find the where abouts of a particular train.
3. The reed contacts are actuated with the aid of a small magnet fitted to the underside of the engine. Depending on the most suitable location of the magnet, T the reed contacts are fitted in between the tracks or along- side the left or right hand rail. Several of these section indication systems may be fitted in series to enable making a con- trol panel with many lights to indicate the train positions. Observing the direction of travel of the trains, section junctions are fitted with S9 (end of previous section) and S1 (begin I of section) located next to each other.
4. This circuit uses LEDs to indicate the train’s position. Each track block is split up into 8 sections, whose starting points are marked with reed contacts (Si-S8).
5. All SET inputs are combined in a NOR gate, N1, which drives a pulse shaper and buffer to reset the bistables with a brief pulse to ensure that only the LED for the last passed track section is lit. 

Indicator circuit for model railway

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LED Indicator Relay Timer Circuit 9 Second

This Relay Timer circuit provides a visual time 9 second delay using ten LED before control by closing a 12 VDC relay. That the reset switch has closed, IC 4017 decade counter will be reset to zero count which illuminates the LED driven from pin 3.

IC 555 timer output at pin 3 will be high and the voltage at pins 6 and 2 of the timer will be a little less than the lower trigger point, or about 3 Vdc.

That time the switch is opened, the transistor in parallel with the timing capacitor (22uF) is shut off allowing the capacitor to begin charging and the IC 555 timer circuit to produce an approximate one second clock signal to the decade counter. The counter advances on each positive going change at pin 14 and is enabled with pin 13 terminated low. When the 9th count is reached, pin 11 and 13 will be high, stopping the counter and energizing the relay. Longer delay times can be obtained with mostcapacitor or most resistor at pins 2 and 6 of the IC 555 timer

Source: 9 Sec Timer with LED indication and Control Relay Circuit

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Audio peak indicator circuit

The existence of the peak indicator (Audio Peak Indicator) in an audio device is needed. Audio Peak indicator is a simple circuit to detect the peak level of audio signal. Audio Peak indicator circuit is built with duabuah transistor and LED indicator as peak level detection of audio signals. 

The main function of a series of Audio Peak indicator is to determine the occurrence of the peak level of audio signal which is more than +4 dB, equivalent to 1.25 V rms. If the received audio signal Audio Peak Indicator more than +4 dB was the LEDs in series Peak Audio This indicator will light. Audio Peak indicator circuit is mounted on the output audio system.

Audio peak indicator

Audio Peak Indicator Component List:
R1 = 10Kohm
R2 = 1.2Kohm
R3 = 220Kohm
R4 = 4.7Kohm
R5 = 4.7Kohm
C1 = 47uF 25V
C2 = 2.2uF 25V
Q1 = BC550C
Q2 = BC550C
D1 = Red Led Read More

Numeric Water Level Indicator Wiring diagram Schematic

Most water-level indicators for water tanks are based upon the number of LEDs that glow to indicate the corresponding level of water in the container. Here we present a digital version of the water-level indicator. It uses a 7-segment display to show the water level in numeric form from0 to 9. The schema works off 5V regulated power supply. It is built around priority encoder IC 74HC147 (IC1), BCD-to-7-segment decoder IC CD4511 (IC2), 7-segment display LTS543 (DIS1) and a few discrete components. Due to high input impedance, IC1 senses water in the container from its nine input terminals. The inputs are connected to +5V via 560-kilo-ohm resistors.

The ground terminal of the sensor must be kept at the bottom of the container (tank). IC 74HC147 has nine active-low inputs and converts the active input into active-low BCD output. The input L-9 has the highest priority. The outputs of IC1 (A, B, C and D) are fed to IC2 via transistors T1 through T4. This logic inverter is used to convert the active-low output of IC1 into active-high for IC2. The BCD code received by IC2 is shown on 7-segment display LTS543. Resistors R18 through R24 limit the current through the display.


When the tank is empty, all the inputs of IC1 remain high. As a result, its output also remains high, making all the inputs of IC2 low. Display LTS543 at this stage shows 0, which means the tank is empty. Similarly, when the water level reaches L-1 position, the display shows 1, and when the water level reaches L-8 position, the display shows 8. Finally, when the tank is full, all the inputs of IC1 become low and its output goes low to make all the inputs of IC2 high. Display LTS543 now shows 9, which means the tank is full. Assemble the schema on a general-purpose PCB and enclose in a box. Mount 7-segment LTS543 on the front panel of the box. For sensors L-1 though L-9 and ground, use corrosion-free conductive-metal (stainless-steel) strips.

Source by : Streampowers

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Automotive Voltage Indicator

Connecting this schema to the battery of your vehicle, you will always know at a glance the approximate voltage available.An indication of battery voltage is useful to the motorist for monitoring the batterys capacity to deliver current, and as a check on the efficiency of the dynamo or alternator.Threshold voltages of the LEDs are set by means of two Zener Diodes (D6 & D10) plus two further Diodes wired in series (D4, D5 and D8, D9 respectively) adding a step of about 1.3V to the nominal Zener voltage.








Parts:
R1,R3,R6________1K 1/4W Resistors
R2____________100K 1/4W Resistor
R4,R5,R7,R8_____3K3 1/4W Resistors
D1__________Red LED (Any dimension and shape)
D2________Amber LED (Any dimension and shape)
D3,D4,D5_____1N4148 75V 150mA Diodes
D6_________BZX79C10 10V 500mW Zener Diode
D7________Green LED (Any dimension and shape)
D8,D9________1N4148 75V 150mA Diodes
D10________BZX79C12 12V 500mW Zener Diode
Q1,Q2_________BC547 45V 100mA NPN Transistors
Q3____________BC557 45V 100mA PNP Transistor



LED indication:
* Red LED D1 is on when battery voltage is 11.5V or less. This indicates a low battery charge. * Amber LED D2 is on when battery voltage is comprised in the 11.5 - 13.5V range. This indicates that the battery is good if the motor is off. When motor is running, this indicates no charge from dynamo or alternator. * Green LED D7 is on when battery voltage is 13.5V or more. This indicates a normal condition when motor is running and dynamo or alternator are charging.

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Under voltage indicator Wiring diagram Schematic

Under voltage indicator Circuit Diagram as use for battery equipment. This is a meter counter schema in this schema 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 Circuit Diagram

Sourcd By : Circuitsstream

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