Vacuum Tubes Valves
Musical & effects
Yagi Uda Antennas
Metal Detector Circuits
Liquid Sensing Circuits
Light Sensing Circuits
Voltage Detector Circuits
Air-Gas Detection Circuits
Human Sensing Circuits
RF & Radiation
Optical Sensing Circuits
Free Energy Circuits
AC to DC & DC to DC
Solar Cell Circuits
Micro Power Circuits
Switching Power Supplies
Light Laser LED
Digital to Analog
Analog to Digital
Data Bus Circuits
Voltage to Pulse
Current to Voltage
Frequency to Voltage
RF Converter Circuits
Sine to Square Wave
Voltage to Current
voltage to frequency
Period to Voltage
Video Wall circuits
TV Video Circuits
Motor Control Circuits
8051 / 8052
PCB CAD Software
Car bike Circuits
555 Timer Circuits
Remote Control Toy
H Bridge Circuit
Interconnection & Timing
Digital Signal Integrity
Digital & Bipolars
Sensors & Detectors
Regulated Power Supply
4 Band Resistor
5 Band resistor
6 Band resistor
Power Supply Circuits
Battery Charger Circuits
Battery Charger Circuits
Lead-Acid Battery Charger Circuit
This circuit delivers an initial voltage of 2.5V per cell to rapidly charge a car battery. The charging current decreases as the battery charges and when t..
Lead and Acid Battery Charger Circuit
Modern acid batteries and lead plates, are embodiment of simplicity in use. Unlike NiCd batteries, they must be recharged by connecting to a constant volta..
Mobile Phone Travel Charger
Here is an ideal mobile charger using 1.5 volt pen cells to charge mobile phone while traveling. It can replenish cell phone battery three or four times in..
Solar Charger Circuit for 6V 4.5Ah Battery
Here is a solar charger circuit that is used to charge Lead Acid or Ni-Cd batteries using the solar energy power. The circuit harvests solar energy to char..
Solar Charger Monitor Circuit
This add on circuit can be attached to the solar charger to see whether the battery is charging or not. It lights a Red LED to indicate that the battery is..
Solar Based Multipurpose Charger Circuit
An ideal solution to harvest Solar energy for charging purpose. This charger can replenish almost all types of batteries including Mobile phone battery. It uses a Solar Module to convert light energy into electrical energy The circuit is self explanatory. A 12 volt 5 Watt solar panel is used as the source of current. The cells in the panel
USB Cellphone Charger circuit
You can charge your Mobile Phone from the USB outlet of PC. This simple usb cellphone charger circuit can give regulated 4. 7 volts for charging the mobile phone. USB outlet can give 5 volts DC and 100 mA current which is sufficient for the slow charging of mobile phones. Most of the Mobile Phone battery is rated 3. 6 volts at 1000 to 1300 mAh.
Cellphone Charger Using Bike Battery
This is the simple and easy way to tap current from a Motor Bike battery to charge the Mobile Phone. Most of the Mobile Phone battery pack has three 1. 2 volt cells making the voltage to 3. 6 volts. For fast charging of the battery pack, each cell requires more than 1. 2 volts and sufficient current. This circuit can deliver 5 volts at 300 mA to...
Solar Inverter Battery Charger
Here is an energy saving solar inverter battery charger. It harvests solar energy to replenish 12 volt inverter battery. It has auto cut off facility to st..
Tricky 12V Battery Charger Circuit
Here is a crude but efficient tricky charger for Lead Acid Battery. It uses a 12 volt car bulb as current regulator and charge status indicator. The bright..
NiCd Battery Charger Circuit
This NiCd baterry charger circuit schematic can charge 6 volts as well as 12 volts NiCad batteries. It uses a transformer which can deliver 4 to 5 A curren..
NiMH Battery Charger Circuit
A simple battery charger for the Nickel Metal Hydride battery that requires current regulated charging. The charger provides 140 mA current for quick charging of the battery. Power supply section consists of a 0-18 volt AC 1 Ampere step-down transformer, a full wave bridge rectifier comprising D1 through D4 and the smoothing capacitor C1.
Automatic Battery Charger Circuit
Here is a 12 volt lead acid automatic battery charger that shut off the charging process once the battery attains full charge. This prevents overcharging o..
12V Voltage Regulated Charger
Most of the battery chargers do not have current and voltage regulation provisions. The step down voltage is simply used for charging. These chargers devel..
12V Battery Charger Circuit
This battery charger circuit can be used to charge one or more batteries with the total nominal voltage of 12 V, meaning ten NiCd battery or six 2 V lead a..
Cell Phone Charger Using 1.5V Battery
Use this cell phone charger circuit and a 1.5V battery when you do not have main power and need to charge your phone
Car Battery Charger Circuit
The car battery charging current is automatically limited to 4. 2A. If there is a 600mV voltage on R1 (4A thru it), then the T1 transistor starts to conduct. Excessive charging current is avoided because the current value on T3 ²s base is limited. The difference between applied load current (at T4 ²s collector) and real voltage of the battery is
12V Battery Charger with SCR
This 12V SCR battery charger circuit differs from the norm in a number of ways, all of which make it difficult to understand
Solar Battery Charger Circuit
This is the most simple and affordable solar battery charger that the hobbyist can make. It has a few drawbacks over other similar controls, but offers numerous advantages. It is intended for charging lead-acid batteries, but may also be used for charging any battery at a constant voltage. Voltage output is adjustable. This is also referred to dro
24V to 36V Battery Charger Circuit
This 24V to 36V linear battery charger is long overdue. While this is an old circuit technique, it is optimized for charging higher voltage lead-acid batte..
Car Relay Charger circuit
Hi Folks, I`m new to the forum and a bit of an electronic newbee, (from an engineering technical perspective, though have tinkered with circuits/schema..
Timer for Charger
Timer for Charger Circuit Diagram. This timer circuit helps to keep the battery in top condition through automatic charging for 5 to 6 hours daily so that the instrument can be left unattended
Battery Charger using Solar & Electrical Power with circuit diagram
Battery Charger using Solar & Electrical Power with circuit diagram. This Dual Power Source battery charger can utilize two power sources to charge a Lead Acid battery
Microchips MCP73113 Li-Ion Battery Charger
Microchip Technology`s MCP73113, MCP73114 and MCP73213 Lithium-Ion (Li-Ion); and MCP73123, MCP73223 Lithium Iron Phosphate (LiFePO4) Chargers feature Overvoltage Protection (OVP), which prevents overheating and damage to the battery-charger circuit from input-voltage spikes. The chargers also feature high-accuracy voltage regulation and an...
Nicad Battery Charger
This simple charger uses a single transistor as a constant current source. The voltage across the pair of 1N4148 diodes biases the base of the BD140 medium power transistor. The base - emitter voltage of the transistor and the forward voltage drop across the diodes are relatively stable. The charging current is approximately 15mA or 45mA with the
Car Battery Charger
This charger will quickly and easily charge most any lead acid battery. Electronics project, easy to build, with circuit diagram included..
IC Controlled Emergency Light With Charger Circuit
Here is the circuit diagram of IC Controlled Emergancy Light With Charger or simply 12V to 220V AC inverter circuit. The circuit shown here is that of the IC controlled emergency light. Its main features are: automatic switching-on of the light on mains failure and battery charger with over-charge protection. When mains is absent, relay RL2 is...
Ni -Cd Batteries Charger circuit
Nicad Battery Charger circuit
his simple charger uses a single transistor as a constant current source. The voltage across the pair of 1N4148 diodes biases the base of the BD140 medium power transistor..
Car Battery 6V or 12V charger circuit
This circuit can charge automatically, fast and rightly, batteries 6V and 12V. A basic factor in the success in the circuit operation is the use of transformer [T1] of good quality with very good insulation and resistance in the short circuits..
3.6 Volt cell phone battery meter circuit
This is a similar circuit to the above and provides a 4 LED bar graph indicating the voltage of a common 3.6 volt Lithium - Ion recharable cell phone battery. The reference voltage is provided by a TL431 programmable voltage source which is set to 3.9 volts where the TL431 connects to the 1K resistor. The lower reference for the LED at pin 14 is...
Free Energy Circuits
AC-DC & DC-DC Circuits
Solar Cell Circuits
Current Limiting Circuits
Micro Power Circuits
High Voltage Circuits
Switching Power Supply Circuits
Ultrasonic distance finder circuit
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
Digital Signal Integrity
Interconnection and Timing of Digital Circuits
CMOS Circuits Tutorial