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
DIY HV Variable Cap
DIY PMA alternator
Interconnection & Timing
Digital Signal Integrity
Digital & Bipolars
Sensors & Detectors
Regulated Power Supply
4 Band Resistor
5 Band resistor
6 Band resistor
Power Supply Circuits
Solar Cell Circuits
Solar Cell Circuits
Solar cell battery charger circuit
The circuit charges a 9-V battery at about 30 mA per input ampere at 0.4 V. Ul, a quad Schmitt trigger, operate as an astable multivibrator to drive push-pull TMOS devices Ql and Q2. Power for Ul is derived from the 9-V battery via D4; power for Ql and Q2 is supplied by the solar cell. The multivibrator frequency, determined by R2-C1, is set to...
Automatic tracking solar controller circuit
As illustrated, the control circuit by the NE555 and phototransistor, R1, C1, C2 and so on. Photodiodes 3DU12 when sunlight to photodiodes, due to its resistance becomes smaller, so that the voltage of the circuit 555 is greater than 6 feet,
12 Volt 20 Amp Solar Charge Controller
The SCC3 is a solar charge controller, it`s function is to regulate the power flowing from a photovoltaic panel into a rechargeable battery. It features easy setup with one potentiometer for the float voltage adjustment, an equalize function for periodic overcharging, and automatic temperature compensation for better battery charging over a wide...
12 Volt 20 Amp Solar Charge Controller
A 12 Volt solar power system can provide power to a wide variety of devices. Some examples include: lighting systems, cellular phones, CB and Ham radios, car stereos, televisions, recording equipment, fans, water pumps, and other low voltage DC loads. With the addition of an inverter, the DC power can be converted to 110 Volts AC for powering an...
Photovoltaic switch disables unused LEDs
In many applications, it`s desirable to disable LEDs used for system verification. Many options are available for the disabling function, including manual SPST (single-pole single-throw) switches, enhancement- and depletion-mode MOSFETs, bipolar-junction transistors, and JFETs. The circuit in Figure 1 automatically disables the LEDs when a...
Remote Solar LED light
The remote solar powered LED light takes advantage of the current limited nature of solar photovoltaic cells. If light shines on the solar array, current will flow through the circuit. For a typical size of solar cell, there is a maximum current that can be produced. The maximum solar cell current is simply matched to a value of current that the...
LED Sensor Electronic Tracker with H-Bridge Drive
I decided to make a commercial surface mount PC board using the LED2 sensor concept. It is quite sensitive and can track to a few degrees of accuracy in bright sunlight. If a blocking shadow is used the accuracy is better then 1/4 degree, that`s about as good as you can get with an active feedback sensor. The board is a tiny .7"x1.4".
Solar Charged LED Utility Light
Tired of always spending money on flashlight batteries only to have them fail just when you need them? Try this simple circuit out. It would make an excellent science fair project. The white LEDs are quite bright, they provide enough light to illuminate a small room at night. The LEDs produce a nicely focused beam. You can read by the light of...
Solar charger for lead-acid batteries
This circuit is intended for charging lead-acid batteries with a solar panel. The customary diode that prevents the battery from discharging through the solar panel has been replaced by a FET-comparator combination. The charger will stop charging once a pre-set voltage (temperature compensated) has been reached, and recommence charging when the...
How would you use an SE with a chip enable? Good question and well one thing leads to another and before you know it a new solar roller is born. The design started out as a simple example of using the 1381wr SE to enable a 74AC240 chip. But with all those spare inverters looking for something to do, the SE kind of got integrated with a whole...
Solar tracking system
No description available.
Zener-based solar engine
The capacitor charges until the PNP transistor (here shown as a 2N3906, but you could also use a BC327) receives base current through the Zener and turns on. Then the NPN transistor (here shown as a 2N3904, but you could also use a BC337) turns on and the capacitor is discharged through the motor. As the NPN turns on the 2.2K resistor...
Solar-powered motor runs on 10 nA
Designs for solar-powered applications with low-duty-cycle requirements can often rely on capacitors for energy storage in place of less reliable batteries. Typical applications include solar positioning, telemetry transmitters, chemical pumps, data loggers, and solar-powered toys. The circuit in Figure 1 can run a small pager motor from the...
Solar Powered Reading Lamp
The reading lamp consists of a small solar panel, a standard UPS style lead acid battery, and an LED circuit board. The circuit board contains a low power solar charge controller (regulator), a set of 8 white LEDs, a switch, an LED current regulator, and a low voltage disconnect circuit. The circuitry will insure a long battery life by...
Well the most common use is in a solaroller which is a small wheeled car that charges up and then moves in a quick burst of speed. Since you can only use motors and coils with this circuit robots built with this circuit are mainly mechanical such as my artistic butterflies. One other common use is a little thing called a symet which can roam...
Solar LED Mood Light
Power this project from sunlight with a CirKits solar power circuit board kit. Other LED lamp circuits can be seen at FC`s Solar Circuits, another interesting LED project is my 13 Color LED Rainbow. This circuit makes a nice lamp that consumes little power, runs cool, and has an incredibly long lifetime. The lamp puts out a warm yellow shade of...
Low-loss circuit powers solar lantern
The solar-lantern circuit in Figure 1 is a low-loss configuration that uses a 7W, four-pin CFL (compact fluorescent lamp) and a 12V, 7-Ahr, sealed, maintenance-free battery. The inverter features greater-than-85% efficiency, less-than-2-mA quiescent current, and a shunt-charge controller with deep-discharge and overcharge protection for the...
6 Amp Solar Power Center
The SPC2 is a solar power center, it can be used to handle all of the power functions for small 12 Volt solar powered devices. It contains a photovoltaic charge controller and a low voltage load disconnect circuit. The low voltage disconnect has a load on-off switch, and a battery low voltage indicator. By using the SPC2 as the center of a solar...
Solar Charge Controller
The design goals of this circuit were efficiency, simplicity, reliability and the use of field replaceable parts. A medium power solar system can be built with the SCC3, a 12V (nominal) solar panel that is rated from 100 milliamps to 20 amps, and a lead acid or other rechargeable battery that is rated from 500 milliamp hours to 400 amp hours of...
PIC16F84 Solar Charger
The previous version of this device used pulse width modulation (pwm) to control the power from the five solar panels to charge the battery bank. Under full sun conditions the MOSFETS got a bit warm and the whole unit radiated a lot of RFI. This design uses a set of relays - one for each panel. If the controller decides the battery voltage is...
Solar Charger circuit
Few years back, I had been working on a project for solar auto lighting. The light will turn on when the the solar panel voltage drop below a set point indicating that it is dark. The detection is done by using D2 in the schematic. The zener diode value will be adjusted so that the transition between the switch depends on the amount of light the...
5v Regulated Solar Power Supply Circuit
This project uses the 1.2v rechargeable battery and solar panel from a Solar Garden Light. These lights can be bought for less than $5.00 in most $2.00 shops or similar shops that sell general household items. We are also using the housing for this project as we could not buy the case, battery and panel for $5.00 in an electronics shop. It is...
Solar Garden LED Lighting
The circuit consists of two stages. The first stage is a "switch" or cut-off device. It detects a voltage above 0.7v from the solar panel and the resistance between its collector-emitter terminals reduces to a very small value. The 10k resistor allows the voltage on the solar panel to rise above 0.7v during bright sunlight, while the 100k...
Solar voltage regulator
The circuit presented here uses linear shunt regulation. Simply spoken, it burns off all excess energy from the panel, keeping output voltage constant. At times when the solar panel output is equal or greater than the load, and the battery is fully charged, the load gets its power from the panel, while the battery rests at full charge. Five...
12V / 4A Solar cell regulator
When the panel isn't generating, the entire circuit is off and there is absolutely no current drain from the battery. When the sun gets up and panel starts producing at least 10 Volt, the LED lights and the two small transistors switch on. This powers the regulator circuit. As long as the battery voltage stays below 14V, the operational...
Solar powered robot
Make your own solar powered robot at home using things you probably already have. Transistors, resistor, capacitor, solar battery and flashing LED are available at any electronic store, if you don't already have them. Solar cells out of calculators work as well, you might want to use more than one since they are really small. If you do, connect...
Digital Clock with Solar Regulator
The basic clock circuit (top schematic below) is similar to the binary clock (on another page) and uses 7 ICs to produce the 20 digital bits for 12 hour time, plus AM and PM. A standard watch crystal oscillator (32,768) is used as the time base and is divided down to 1/2 half second by the 4020 binary counter. One half of a 4013 data latch is...
Solar Powered Garden Lamp Circuit with Light Sensor
This is a reverse engineered circuit diagram of yet another commercially produced solar garden lamp. To turn the light on at night, this depends upon a CDS photocell. It allows the battery to charge more efficiently although more complex than the circuits. This is the figure of the circuit;
1n5818 Solar Charger Controller
Solar Power walkway marker Led display
These are the little lights with the stake on the bottom that you can push into the ground along your driveway or sidewalk and have the solar panel on top. The solar cell charges a AA NiCd battery during the day and at night the battery powers the LED. The circuit board in this particular model was originally designed to hold a pair of 5mm amber L
Solar Powered Lantern
This is a quick DIY electronics project I set for myself so I could brush up on my circuit design and some building techniques. I bought a couple copper lanterns off ebay and fitted them with a circuit similar to the outdoor solar lights you can buy for your yard. Much of the circuit design is based on one of the simple designs on Evil Mad Scienti
Arduino 2-axis servo solar tracker
I marked the approximate center of the base and drilled a hole large enough to screw the setscrew for the servo armature in. I then hot glued the armature to the underside of the base making sure not to get glue in the hole i drilled. I used 3 light sensors and 1 tilt sensor. You can substitute LEDs orphoto-transistors for the CDS cells, and/or me
Free Energy Circuits
Battery Charger Circuits
AC-DC & DC-DC 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...
DIY HV Variable Capacitor
DIY PMA Alternator Plans
Digital Signal Integrity