Water Alarm Circuit >>

Have you ever seen the stairs to one of the upper stories in your house turn into a waterfall? Or maybe you’ve come home to find your aquarium fish trying to swim across the carpet? For your sake, we hope not, because the consequences are usually fairly dramatic. With a handful of electronic components, you can at least ensure that you will be warned before you have to put on your waders. It’s better to prevent water problems than to have to correct them. But no how many precautions you take, an occasional leak can still happen.

A burst water supply hose for the washing machine, a bath tap that someone forgot to turn off, a broken aquarium wall, or a leaking boiler or central heating tank – anything is possible. In such cases, it’s nice to be warned as quickly as possible, for example by an acoustic water alarm. Then you can at least limit the damage. If you’re handy with a soldering iron and know the difference between an IC and a PC, you’ll no doubt enjoy building the electronic water alarm described here.

The circuit takes advantage of the fact that ‘normal’ water is always slightly contaminated, even if only slightly, and thus conducts electricity to a certain extent. It is built around an popular IC from the somewhat antiquated 4000-series logic family: the 4093. This IC contains four inverted-output AND gates (NAND gates) with Schmitt-trigger inputs. If water is detected between the probes, it emits an intermittent and rather irritating beeping tone.

 

Laser Alarm Circuits >>

This circuit may be a optical device alarm just like the one we tend to see in varied movies. It uses a optical device pointer beam to secure your valuables and property. primarily, once the beam gets interrupted by someone, animal or object, the resistance of a photodiode can increase associated an alarm are going to be activated. The optical device and therefore the receiver will be fitted in same box, sharing a standard power offer. because the receiver attracts but ten mA on the average, you’ll before long notice that the optical device is that the most current hungry device! Mirrors area unit accustomed direct the beam in no matter setup you need. samples of a passage and {an area unita|a neighborhood|a district|a region|a locality|a vicinity|a part|a section} protected by the alarm are shown within the diagram.

Alarm Translator Mini Circuits

This circuit, fenced in a very tiny plastic box, will be placed into a bag or purse. alittle magnet is placed near the reed switch and connected to the hand or the garments of the person carrying the bag by means that of a small twine. If the bag is snatched dead, the magnet looses its contact with the reed switch, SW1 opens, the circuit starts periodical and therefore the speaker system emits a loud alarm sound. A complementary transistor-pair is wired as a high potency generator, directly driving alittle speaker system. Low part-count and 3V battery provide enable a really compact construction.

Parts:

R1 = 330K
R2 = 100R
C1 = 10nF-63V
C2 = 100uF-25V
Q1 = BC547
Q2 = BC327
B1 = 3V Battery or Two AA Cells in Series
SW1 = Read Switch & Small Magnet
SPKR = 8R Loudspeaker (See Notes)

Speed Alarm Circuit For Cars

In normal suburban driving you pass through so many different speed zones that it can be a nuisance having to switch speed settings. The speed display can also be a distraction. This circuit eliminates the display and the need for speed selection. Each time you exceed a particular speed setting (eg, 40km/h, 50km/h, etc), a piezo buzzer will beep. Speed pulses are fed to the base of Q1 and the resulting waveform at its collector is fed via an RC network to the input of an LM2917 frequency-to-voltage converter, IC1. The resulting voltage is fed to three comparators (IC2d-IC2b) which have the reference voltages at their inverting inputs set by 10-turn trimpots VR1, VR2 & VR3. The output of each comparator is applied via another RC network to the gate of an SCR. The anodes of the three SCRs are commoned connected to the inverting input of the remaining comparator, IC2a.

Circuit Diagram

Its non-inverting input is set to +2.3V by trimpot VR4. In use, once you exceed the speed setting for a particular comparator, its associated SCR briefly conducts to pull pin 2 of IC2a low and a short beep is emitted by the piezo buzzer. Then, as you exceed the next speed setting, another beep will be heard. The idea is make each speed setting a few km/h higher than actual so that if you are driving at the correct speed in a given zone, the buzzer will not sound. But as you increase speed, the buzzer will beep once as you exceed the speed setting for each zone. In this way, there is no need to continually switch speed settings as you drive through different zones and you can choose to ignore beeps that are not "illegal".Electronics Circuit Application

Author: Col Edwards - Copyright: Silicon Chip Electronics Magazine

IC Using Two-Tone Siren Circuits

This circuit is intended for children fun, and can be installed on bicycles, battery powered cars and motorcycles, but also on models and various games and toys. With SW1 positioned as shown in the circuit diagram, the typical dual-tone sound of Police or Fire-brigade cars is generated, by the oscillation of IC1A and IC1B gates. With SW1 set to the other position, the old siren sound increasing in frequency and then slowly decreasing is reproduced, by pushing on P1 that starts oscillation in IC1C and IC1D.

The loudspeaker, driven by Q1, should be of reasonable dimensions and well encased, in order to obtain a more realistic and louder output. Tone and period of the sound oscillations can be varied by changing the values of C1, C2, C5, C6 and/or associated resistors. No power switch is required: leave SW1 in the low position (old-type siren) and the circuit consumption will be negligible.

 

 Circuit diagram

Parts List:

R1 = 470K - 1/4W Resistors
R2 = 680K - 1/4W Resistor
R3 = 470K - 1/4W Resistors
R4 = 82K - 1/4W Resistor
R5 = 330K - 1/4W Resistor
R6 = 10K - 1/4W Resistor
R7 = 33K - 1/4W Resistor
R8 = 3.3M - 1/4W Resistor

C1 = 10µF - 25V Electrolytic Capacitors
C2 = 10nF - 63V Polyester Capacitors
C3 = 100nF - 63V Polyester Capacitor
C4 = 100µF - 25V Electrolytic Capacitor
C5 = 10µF - 25V Electrolytic Capacitors
C6 = 10nF - 63V Polyester Capacitors

D1 = 1N4148 - 75V 150mA Diodes
D2 = 1N4148 - 75V 150mA Diodes
D3 = 1N4148 - 75V 150mA Diodes

Q1 = BC337 - 45V 800mA NPN Transistor
P1 = SPST Pushbutton
B1 = 6V Battery (4 AA 1.5V Cells in series)
IC1 = 4093 - Quad 2 input Schmitt NAND Gate IC
SW1 = DPDT Switch
SPKR= 8 Ohm Loudspeaker  Electronics Circuit Application

Night Alert Circuits ..

Idea of this circuit came to me at midnight when my pet dog started barking continuously on sensing a moving shadow, perhaps that of an intruder. Dogs have a night adaptation capability to maximise the sensitivity of vision in low light. They are well adapted to see moving objects rather than stationary ones in darkness. This circuit turns a lamp ‘on’ for a short duration when the dog barks, giving an impression that the occupants have been alerted.

The condenser microphone fitted in the dog’s cage senses barking sound and generates AC signals, which pass through DC blocking capacitor C1 to the base of transistor BC549 (T1). Transistor T1 along with transistor T2 amplifies the sound signals and provides current pulses from the collector of T2.


The input trigger pulse is applied to the collector of transistor T3 and coupled by capacitor C3 to the base of transistor T4 causing T4 to cut off. The collector voltage of transistor T4 forward biases transistor T3 via resistor R8.Transistor T1 conducts and capacitor C3 discharges to keep transistor T4 cut-off. Transistor T4 remains cut-off until capacitor C3 charges enough to enable it to conduct. When transistor T4 conducts, its collector voltage goes low to drive transistor T3 into cut-off state. Resistor R9 and capacitor C3 are timing components. When fully charged, capacitor C3 takes about two minutes to discharge. So when sound is produced in front of the condenser mic, TRiAC1 (BT136) fires and the bulb (B1) glows for about two minutes.

Assembly instruction:

Assemble the circuit on a general-purpose PCB and enclose in a plastic cabinet. Power to the circuit can be derived from a 12V, 500mA step-down transformer with rectifier and smoothing capacitor. Solder the triac ensuring sufficient spacing between the pins to avoid short circuit. Fix the unit in the dog’s cage, with the lamp inside or outside as desired. Connect the microphone to the circuit using a short length of shielded wire. Enclose the microphone in a tube to increase its sensitivity.

Warning:

Since the circuit uses 230V AC, many of its points are at AC mains voltage. it could give you lethal shock if you are not careful. So if you don’t know much about working with line voltages, do not attempt to construct this circuit. EFY will not be responsible for any kind of resulting loss or damage.
Electronics Circuit Application 

Author: D. Mohan Kumar - Copyright: Electronics For You Mag

power buzzer circuits >>

How usually on the average does one ought to decision members of your family daily to inform them that dinner is prepared, it’s time to go away, and therefore the like? The person you wish is typically during a completely different area, like the hobby area or chamber. a strong buzzer within the area, combined with a pushbutton at very cheap of the steps or within the room, might be terribly handy in such things. the guts of this circuit is made by IC1, a TDA2030. This IC has inbuilt thermal protection, therefore it’s not going to quickly quit the ghost. R1 and R2 apply a voltage capable [*fr1] the availability voltage to the and input of the opamp. R3 provides regeneration. Finally, the mix of C2, R4 and trimmer P12 determines the oscillation frequency of the circuit.

12V battery charger circuit using LM311

The best twelve potential unit charger circuit our this is often a charger circuit automatic system, then once the battery voltage is not up to fixed, this circuit provides power to the battery now and stops charging once the battery is totally solely. therefore ideal to be used in emergency power provide or battery backup grid the least bit kind. and definitely, if you apply to your automobile battery, it doesn't have any rules.
And the most vital is that the worth that was very terribly. we'll quickly build is out there.

Stereo Preamplifier with Bass boost circuits >>

High Quality simple design

20V to 30V supply Circuits.

 

Circuit diagram

Parts:

P1_________________10K   Log.Potentiometer (Dual-gang for stereo)
P2________________100K   Log.Potentiometer (Dual-gang for stereo) (See Notes)

R1,R2_____________100K   1/4W Resistors
R3,R6______________15K   1/4W Resistors
R4_________________10K   1/4W Resistor
R5_________________22K   1/4W Resistor
R7__________________1K   1/4W Resistor
R8________________560R   1/4W Resistor

C1,C2,C5____________2µ2   63V Electrolytic Capacitors
C3________________470µF   35V Electrolytic Capacitor
C4__________________1µF   63V Polyester Capacitor
C6_________________47nF   63V Polyester Capacitor
C7_________________22µF   25V Electrolytic Capacitor

IC1_______________TL072  Dual BIFET Op-Amp

SW1________________DPST  Switch (Optional, see Notes)

Comments

This preamplifier was designed to cope with CD players, tuners, tape recorders etc., providing an ac voltage gain of 4, in order to drive less sensitive power amplifiers. As modern Hi-Fi home equipment is frequently fitted with small loudspeaker cabinets, the bass frequency range is rather sacrificed. This circuit features also a bass-boost, in order to overcome this problem. You can use a variable resistor to set the bass-boost from 0 to a maximum of +16dB @ 30Hz. If a fixed, maximum boost value is needed, the variable resistor can be omitted and substituted by a switch.

Notes:

• Schematic shows left channel only, but R1, R2, R3 and C1, C2, C3 are common to both channels.
• For stereo operation P1, P2 (or SW1), R4, R5, R6, R7, R8 and C4, C5, C6, C7 must be doubled.
• Numbers in parentheses show IC1 right channel pin connections.
• A log type for P2 ensures a more linear regulation of bass-boost.
• Needing a simple boost-in boost-out operation, P2 must be omitted and SW1 added as shown in the diagram.
• For stereo operation SW1 must be a DPST type.
• Please note that, using SW1, the boost is on when the switch is open, and off when the switch is closed.Electronics Circuit Application

0.7V - 24V DC Variable Power Supply Circuits >>

Voltage range: 0.7 - 24V
Current limiting range: 50mA - 2A

Parts:

P1____________500R   Linear Potentiometer
P2_____________10K   Log. Potentiometer

R1,R2___________2K2  1/2W Resistors
R3____________330R   1/4W resistance
R4____________150R   1/4W resistance
R5______________1R     5W resistance

C1___________3300µF   35V capacitance (see Notes)
C2______________1µF   63V Polyester electrical device

D1,D2________1N5402 200V 3A Diodes
D3_____________5mm. Red LED

Q1____________BC182  50V 100mA NPN semiconductor unit
Q2____________BD139  80V one.5A  NPN semiconductor unit
Q3____________BC212  50V 100mA PNP semiconductor unit
Q4 __________2N3055  60V 15A   NPN semiconductor unit

T1_____________220V Primary, 36V Center-tapped Secondary
               50VA Mains electrical device (see Notes)

PL1____________Male Mains plug

SW1____________SPST Mains switch
Device purpose:

A Variable DC Power offer is one in all the foremost helpful tools on the physical science hobbyist's work table. This circuit isn't Associate in Nursing absolute novelty, however it's straightforward, reliable, "rugged" and short-proof, that includes variable voltage up to 24V and variable current limiting up to 2A. compatible to produce the circuits shown during this web site. you'll be able to adapt it to your own necessities as explained within the notes below.

Notes:

• P1 sets the maximum output current you want to be delivered by the power supply at a given output voltage.
• P2 sets the output voltage and must be a logarithmic taper type, in order to obtain a more linear scale voltage indication.
• You can choose the Transformer on the grounds of maximum voltage and current output needed. Best choices are: 36, 40 or 48V center-tapped and 50, 75, 80 or 100VA.
• Capacitor C1 can be 2200 to 6800µF, 35 to 50V.
• Q4 must be mounted on a good heatsink in order to withstand sustained output short-circuit. In some cases the rear panel of the metal box in which you will enclose the circuit can do the job.
• The 2N3055 transistor (Q4) can be replaced with the slightly less powerful TIP3055 type.
•  Electronics Circuit Application

60 Watt Audio Power Amplifier Circuit >>

High Quality, powerful unit: 90W into four Ohm load, conjointly suited as stringed instrument or bass electronic equipment

To celebrate the hundredth style announce to the current web site, Associate in Nursingd to fulfil the requests of the many correspondents wanting an electronic equipment a lot of powerful than the 25W MosFet, a sixty - 90W prime quality power electronic equipment style is conferred here. Circuit topology is concerning a similar of the on top of mentioned electronic equipment, however the very rugged IRFP240 and IRFP9240 MosFet devices square measure used because the output try, and well famed high voltage Motorola's transistors square measure utilized within the preceding stages.

The supply rails voltage was unbroken prudentially at the rather low price of + and - 40V. For those want to experiment, the provision rails voltage may well be raised to + and - 50V most, permitting the electronic equipment to approach the 100W into eight Ohm target: enjoy! an identical, separate elements, standard Preamplifier style is obtainable here: standard Audio Preamplifier.

Parts:

R1______________47K 1/4W resistance
R2_______________4K7 1/4W resistance
R3______________22K 1/4W resistance
R4_______________1K 1/4W resistance
R5,R12,R13_____330R 1/4W Resistors
R6_______________1K5 1/4W resistance
R7______________15K 1/4W resistance
R8______________33K 1/4W resistance
R9_____________150K 1/4W resistance
R10____________500R 1/2W Trimmer Cermet
R11_____________39R 1/4W resistance
R14,R15_________R33 two.5W resistances
R16_____________10R two.5W Resistor
R17_____________R22 5W resistance (wirewound)
C1_____________470nF 63V Polyester electrical condenser
C2_____________470pF 63V styrene or ceramic electrical condenser
C3______________47µF 63V electrolytic
C4,C8,C9,C11___100nF 63V Polyester Capacitors
C5______________10pF 63V styrene or ceramic electrical condenser
C6_______________1µF 63V Polyester electrical condenser
C7,C10_________100µF 63V Electrolytic Capacitors
D1___________1N4002 100V 1A Diode
D2_____________5mm. Red LED
Q1,Q2,Q4_____MPSA43 200V 500mA NPN Transistors
Q3,Q5________BC546 65V 100mA NPN Transistors
Q6___________MJE340 200V 500mA NPN semiconductor
Q7___________MJE350 200V 500mA PNP semiconductor
Q8___________IRFP240 200V 20A N-Channel Hexfet semiconductor
Q9___________IRFP9240 200V 12A P-Channel Hexfet semiconductor


Power supply

 Parts:
R1_______________3K9 1W resistance
C1,C2_________4700µF 63V Electrolytic Capacitors (See Notes)
C3,C4__________100nF 63V Polyester Capacitors
D1_____________400V 8A Diode bridge
D2_____________5mm. Red LED
F1,F2__________4A Fuses with sockets
T1_____________230V or 115V Primary, 30+30V Secondary 160VA Mains electrical device
PL1____________Male Mains plug
SW1____________SPST Mains switch

Notes:

 within the original circuit, a three-diode string was wired serial to R10. 2 of those diodes ar currently replaced by a red light-emitting diode so as to realize improved quiescent current stability over a bigger temperature vary. due to David Edwards of LedeAudio for this suggestion.
    A small, U-shaped heatsink should be fitted to Q6 & Q7.
    Q8 & Q9 should be mounted on massive heatsinks.
    Quiescent current is measured by means that of associate Avo-meter wired serial to the positive provide rail and no signaling.
    Set the Trimmer R10 to its minimum resistance.
    Power-on the electronic equipment and change R10 to browse a current drawing of regarding a hundred and twenty - 130mA.
    Wait regarding quarter-hour, watch if the present is variable and readjust if necessary.
 the worth instructed for C1 and C2 within the Power provide elements List is that the minimum needed for a mono electronic equipment. For optimum performance and in stereo configurations, this price ought to be increased: 10000µF may be a sensible compromise.
 an accurate grounding is incredibly necessary to eliminate hum and ground loops. connect with identical purpose the bottom sides of R1, R3, C2, C3 and C4 and therefore the ground input wire. Connect R7 and C7 to C11 to output ground. Then connect singly the input and output grounds to the ability provide ground.

Technical data:

•     Output power:

•    sixty Watt RMS @ eight Ohm (1KHz sinewave) - 90W RMS @ four Ohm

             Sensitivity:

•     1V RMS input for 58W output

•     Frequency response:

•     30Hz to 20KHz -1dB

•     Total harmonic distortion @ 1KHz:

•     1W 0.003% 10W 0.006% 20W 0.01% 40W 0.013% 60W 0.018%

•     Total harmonic distortion @10KHz:

•     1W 0.005% 10W 0.02% 20W 0.03% 40W 0.06% 60W 0.09%

• Unconditionally stable on capacitive loads Electronics Circuit Application

Mobile phones charger Circuits 6v to 12v

Most mobile chargers don't have current/voltage regulation or short-circuit protection. These chargers give raw 6-12V DC for charging the battery pack. Most of the mobile battery packs have a rating of three.6V, 650mAh. For increasing the lifetime of the battery, slow charging at low current is judicious. Six to 10 hours of charging at 150-200mA current could be a appropriate possibility. this may stop heating from the battery and extend its life.

Circuit diagram:

Parts:

Resistors:

P1 = 10K LOG
R1 = 1K
R2 = 1K
R3 = 1K
R4 = 1K
R5 = 3.3K
R6 = 16R/2W
R7 = 220R
R8 = 3.3R
R9 = 1K

Capacitors:

C1 = 470uF/25V
C2 = 10uF/25V
C3 = 1KuF/25V

Semiconductors:

D1 = Red LED
D2 = Green LED
Q1 = BC547
Q2 = BD677
ZD1 = 12V/1W
ZD2 = 5.6V/1W
IC1 = CA3130

 Description:The circuit delineate here, provides around 180mA current at five.6V and protects the transportable from surprising voltage fluctuations that develop on the mains line. that the charger may be left ‘on’ over night to fill again the battery charge. The circuit protects the transportable moreover because the charger by straight off disconnecting the output once it senses a voltage surge or a brief circuit within the battery pack or instrumentation. It may be known as a ‘middle man’ between the present charger and therefore the transportable.

It has options like voltage and current regulation, over-current protection, and high- and low-tension cut-off. an extra specialty of the circuit is that it incorporates a brief delay of 10 seconds to change on once mains resumes following an influence failure. This protects the transportable from instant voltage spikes. once short-circuit happens at the battery terminal, resistance R8 senses the over-current, permitting Q1 to conduct and lightweight up D1. Glowing of D2 indicates the charging mode, whereas D1 indicates short-circuit or over-current standing.

The value of resistance R8 is very important to urge the specified current level to work the cut-off. With the given worth of R8 (3.3 ohms), it's 350 mA. Charging current may also be modified by increasing or decreasing the worth of R7 exploitation the ‘I=V/R’ rule. Construct the circuit on a standard PCB and house in an exceedingly little plastic case. Connect the circuit between the output lines of the charger and therefore the input pins of the transportable with correct polarity.

Electronics Circuit Application 

China GSM phone white display solution >>

Welcome to the mobile phone repairing tips blog.This is my farts  post on blog.my name is Rizwan Naz and i am a mobile repairing expert.My blog is all about the mobile phone;s software and hardware solution.Whenever you will visit my blog you will find the all solution of your any kind of cell phone.Here you can find all the cell phone repairing tips,applications,software,blackberry software information,nokia  mobile phone all models china all models solution.Today china mobile phone is very famous around the world but some time it create a problem white screen.It held after few second and became white display.There tow reason first your mobile phone put down on the floor and second your mobile phone water damage.
china mobile have many models but hardware have same software different.This picture have a one china mobile phone bored and seven IC;s same IC small and three main IC big and big one UUP IC and second REM thread is power IC >>

 If you china mobile phone create a problem white display.
First of all you open a mobile with sample  mobile phone tools and put the mobile phone bored same  this picture and rehot the UUP IC.Then your china mobile phone problem 100% solve.
If you like my blog and you want to know about the cell phone repairing tips.please give me your comments. 
Electronics Circuit Application 

DC-DC Converter Micropower circuits LT1073 >>

 

Features

• No Design Required
• Operates at Supply Voltages From 1.0V to 30V
• Consumes Only 95µA Supply Current
• Works in Step-Up or Step-Down Mode
• Only Three External Off-the-Shelf Components Required
• Low-Battery Detector Comparator On-Chip
• User-Adjustable Current Limit
• Internal 1A Power Switch
• Fixed or Adjustable Output Voltage Versions
• Space-Saving 8-Pin MiniDIP or SO8 Packag

Typical Application

 

Description

The LT1073 is a versatile micropower DC/DC converter. The device requires only three external components to deliver a fixed output of 5V or 12V. The very low minimum supply voltage of 1V allows the use of the LT1073 in applications where the primary power source is a single cell. An on-chip auxiliary gain block can function as a low-battery detector or linear post-regulator. Average current drain of the LT1073-5 used as shown in the Typical Application circuit below is just 135µA unloaded, making it ideal for applications where long battery life is important. The circuit shown can deliver 5V at 40mA from an input as low as 1.25V and 5V at 10mA from a 1V input.
The device can easily be configured as a step-up or step-down converter, although for most step-down applications or input sources greater than 3V, the LT1173 is recommended. Switch current limiting is user-adjustable by adding a single external resistor. Unique reverse-battery protection circuitry limits reverse current to safe, nondestructive levels at reverse supply voltages up to 1.6V.

Applications

• Pagers
• Cameras
• Single-Cell to 5V Converters
• Battery Backup Supplies
• Laptop and Palmtop Computers
• Cellular Telephones
• Portable Instruments
• 4mA-20mA Loop Powered Instruments
• Hand-Held Inventory Computers
• Battery-Powered Alpha, Beta and Gamma Particle Detectors Electronics Circuit Application

LM386 audio amplifier circuit and PCB >>

This is associate amplifier which will be used with atiny low nine potential unit Battery Operated,Current use as very little as five milliamps.And amplification up to five hundred mW.
Which is spare to expand the sound from a sound concerning or the CD Walk Man bent the tiny speakers clearly.
When coming into the ability provide 9-volt circuit IC1 range LM386 electronic equipment IC size is 300-800 mW, looking on the ability provide circuit with,This is from 4-15 volts.

Once entered into the input pin three,The non inverting pin to electronic equipment non-return part.C1 are going to be served cut out the noise input to ground.And C2 will increase the speed of electronic equipment,C2 is to feature additional price.But if the C2 an excessive amount of distortion (the C2 mustn't exceed 100uF).The output of IC1 is out of the pin five through C4 coupling audio signals to raised and DC block and not passed to the speaker.For the audio portion will be fed back through R2 and C3 to the high frequency response higher.Electronics Circuit Application

Lead Acid Battery Meter with LM339 Circuirs >>

In the circuit below, a quad potential unitage comparator (LM339) is employed as a straightforward chart meter to point the charge condition of a twelve volt, lead acid battery. A five potential unit reference voltage is connected to every of the (+) inputs of the four comparators and therefore the (-) inputs area unit connected to sequent points on a resistor. The LEDs can illuminate once the voltage at the negative (-) input exceeds the reference voltage. activity is done by adjusting the 2K potentiometer so all four LEDs illuminate once the battery voltage is twelve.7 volts, indicating full charge with no load on the battery. At 11.7 volts, the LEDs ought to be off indicating a dead battery. every junction rectifier represents AN approximate twenty fifth amendment responsible condition or three hundred millivolts, so three LEDs indicate seventy fifth, two LEDs indicate five hundredth, etc. the particular voltages can depend upon temperature conditions and battery sort, wet cell, gel cell etc. Electronics Circuit Application

24V SCR Battery Charger circuits. >>

This is AN extension of the earlier 12V SCR device.

It is astonishingly straightforward to increase the output voltage to 24V, but there ar every obvious and delicate variations to believe. the foremost obvious distinction is that the transition from full-wave center-tapped to a full-wave bridge configuration. throughout this case, the full-wave bridge is further specifically a semiconverter bridge that contains a pair of rectifiers and a couple of thyristors (silicon controlled rectifiers or SCRs). This project is not advised for the novice, as advanced trouble-shooting skills ANd AN electronic equipment might even be required to induce it up and running.

 

Electronics Circuit Application 

Li-Ion Battery Charger Circuits >>

This is a circuit of an easy single cell li particle battery chager. This Li particle device circuit uses a LP2931 regulator IC. The diode is functioning as a current blocker to prevet this flow back within the IC once there's no voltage on the IC input.The output voltage will be adjuted   

with 50k potentiometer between four.08V to 4.26V. The circuit provides 100mA of charging current. The charging current is 100mA owing to that it'll take some longer to charge the li particle battery therefore the circuit is sweet for mistreatment as a long charger.
  Electronics Circuit Application