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
Scientific Calculator Watch
The uWatch comes as a kit of parts. All of the electronic SMD parts on the PCB are pre-assembled. The uWatch is normally in sleep mode and powers down the LCD to save battery power. (approx 3mA LCD on, and 15uA LCD off) To switch the uWatch on press either the MODE key or the RCL/STO key. The uWatch has three "modes": 1) Time/Date display. 2)...
R/C Airplane LED Flasher
This was designed to flash a pair of LEDs to be mounted on the wing tips of a Parkzone Citabria R/C (remote control) airplane. The unmodified Parkzone Citabria only weights 20 grams (about 0.7 oz), so weight, and therefore the number and size of the electrical components for the flasher are critical. Another major constraint was the range of...
Morse Code Alarm Clock
(Almost) Trivial application of an AT90S2313 or ATtiny2313 in an alarm clock to change the alarm from "BEEP BEEP BEEP BEEP BEEP BEEP BEEP BEEP..." to "WAKE UP" in Morse code. This was designed in response to a request and is in daily use. An inexpensive alarm clock was modified by installing a small circuit board inside the clock body and...
Knight Rider Lights
The 555 timer IC is connected for Astable Operation, the clock pulses are fed to the 4017 IC via the 10K resistor. The 4017 is a 10 stage counter, each of the outputs is connected to the appropriate LED, as some LEDs need to be on for more than one count, we use diodes to avoid a short circuit situation between outputs. The capacitor and...
Tone generator with 555
This circuit is based around the 555 timer circuit, used as an astable (free running) oscillator. The frequency (pitch) of the tone is set by the resistors and capacitors in the left side of the circuit. The first one is a potentiometer (variable resistor), this is our pitch control, which is basically all the external components you need. The...
LED runner with 74LS163
This is a very simple circuit to build, just take note of the control pins on each IC, since both have enable inputs for counting or output, but once set you don't need to worry about them. From left to right, the first IC is a binary counter, 74ls163, that is used to generate the address numbers we are going to use in the second part of the...
Incect Robot circuit (PIC16F818)
Very little extra circuitry is needed to do both forword and backword walking sequences along with a few other tricks. The PIC16F818 has a lot of features that work well in this situation. As you can see from the Schematic and Source Listing, position pulses for the 2 servos are generated dirctly from the PIC. Also, the room light level,...
Audio Controlled Christmas Lights
The basic Idea was to have Christmas lights flash with the music. In my design I use an ordinary amplified computer speaker, a diode bridge, and a ‘CRYDOM’ SSR (Solid State Relay). In order to increase the time that the lights were on as well as protect the SSR I used a Diode Bridge to rectify the signal from the amplifier circuit.”
A Talking Fish using PIC16F819
These items were sold nationally several years ago. The fish would sing, open its mouth, turn its head, and flap its tail. After removing the back panel, all of the existing electronics were removed leaving only the 3 servo motors, speaker and photocell. The reworked insides are shown here. Wires from each of the motors and from the photocell...
Talking Frog Box using PIC16F870
This device 'listens' to a conversations and then interjects words and phrases at inappropriate times. I got this box at a local thrift store for $1.50 (special, this week only). It has a nice hinged top and a place to insert a panel with a designed glued to it. Ok, so I found this frog on the net and dug up the Egyption boarder from somewhere...
Roulette with LED Display
This circuit is a small digital ?roulette''. It is constituted by oscillator IC1, the counter IC2, the transistors Q1-7 that drive the display common cathode DSP1. The supply basically becomes from a battery 9V, but can become also from one power supply. The regulation of frequency should become in the 10HZ or little bigger, with to...
LED Dice circuit
The IC1 is a 555 timer IC is connected for, Astable operation the clock pulses are fed to the IC2 via the 10K resistor. The IC2 is a 10 stage counter, output 6 (pin 5) is connected to RESET (pin 15), thus giving us a 6 stage counter , outputs 0 to 5. The 6 of the LEDs are connected as 3 pairs, thus requiring 4 different signals, these signals...
LED Dice II
The particular circuit is substantially a generator of accidental numbers, from 1 until the 6. The clue him we see in a line from led, that each one corresponds also in a number from the 1-6, if push and leave, the S1 (push button). This movement corresponds in a movement of dice. The led that it turned on will remain turned on for five until...
10 Led Chaser
This circuit us gives the sense of movement of ball up down, after the LED turn on successively the one afterwards the other. As soon as it reaches in the one or in the other end it makes again the opposite movement to behind. As clock are used two inverters IC3A-B, the third IC3C are have role buffer. The R1, TR1, C1, determine the frequency,...
16 LED Chaser
This circuit is a double direction flash. Similar to Digital Ping- Pong 1, there is a movement of a lit dot, up and down along the LED's length. When the D16 lit the situation changes and there is a reverse movement. Lit D15-14 ??D16, is lit making circles when the circuit is under power. The IC1 is an unstable flip- flop supplying with stable...
Robot Beacon with PIC12C508A
We hold the "first rights" to the presentation of this approach and the best part is: "It's FREE!" The PIC12C508A is one of the most amazing devices but because it does not come in a low-cost re-programmable form, it has never been presented in a "designers article." It is a one-time programmable device (OTP) and once it is programmed, it...
Melody generator schematic
This tiny circuit comprising of a single 3 terminal IC UM66 can be built small enough to be placed inside a greeting card and operated off a single 3V flat button cell. There is not much to the circuit. The UM66 is connected to its supply and its output fed to a transistor for amplification. You can either use a 4ohm speaker or a " flat"...
Scoring Game circuit
You can play this game alone or with your friends. The circuit comprises a timer IC, two decade counters and a display driver along with a 7-segment display. The game is simple. As stated above, it is a scoring game and the competitor who scores 100 points rapidly (in short steps) is the winner. For scoring, one has the option of pressing either...
Quiz game schematic
This jam circuit can be used in quiz contests wherein any par- ticipant who presses his button (switch) before the other contestants, gets the first chance to answer a question. The circuit given here permits up to eight contestants with each one allotted a distinct number (1 to 8). The display will show the number of the contestant pressing his...
LED flashing circuit for toys
It consists of a 4047 low-power monostable/astable multivibrator, IC1, used in the astable mode to provide the timing pulses to control the flash rate of the LEDs. To accomplish the astable mode, pins 4, 5, 6, and 14 are connected to +12VDC and pins 7, 8, 9, and 12 are connected to ground. Pins 1 and 3 are connected to C2 and pins 2 and 3 are...
LED Traffic Lights for Games
This schematic uses the 555 timer and the 4017 IC to drive 3 LED, to simulate the trafic lights.
Flashing LEDs toy with 555
There have described the involvement benefited LM3909 circuit, which is quite expensive. That's why I prefer to use a much cheaper known timer 555th.Involvement of the tree is a very simple scheme is to figure 2 . It is based on several multivibrator used as a favorite flasher timer 555 in the simplest possible involvement. Each flasher controls...
Fading LEDs schematic
This circuit is used to slowly illuminate and fade a pair of red LEDs (light emitting diodes). The fading LEDs could be installed as 'eyes' in a small pumpkin or skull as a Halloween attraction, or mounted in a Christmas tree ornament. Or, they might be used as a fancy power indicator for your computer, microwave oven, stereo system, TV, or...
Railway Grade Crossing Circuit
The protected section of track can be as long or as short as desired and does not have to be the same length on both sides of the crossing. The circuit works in both directions and can be connected to other grade crossing circuits to provide fully automatic protection for multiple track crossings. The Grade Crossing circuit provides prototypical o
Atari 2600 CE
Since we will be opening your VCS and attacking it with a very hot soldering iron, it is possible that you will render your system dead. Neither I, Classicgaming, nor Gamespy are responsible for any damage done to yourself, your Atari, your family, your pets, your house, your neighborhod, or your precious Faberge egg collection that results either
AVR TV Game
Martin ustek has modified the project to also include a Sokoban game. Some information about his version can be found dotted throughout this page; for full details, please visit his website (Czech). Either game can be selected with a menu that appears when you power up the circuit. Tetris was developed first, and so doesn`t show this menu in the f
Tech Toy Hacks
The interface depicted below can be used build a serial cable to connect the serial port of the computer to the 16-pin OBD-II connecter found in many cars build in 1996 or later. This interface only supports the ISO 9141-2 / ISO 14230-2 K-line tranfer mode. If in your ODB connecter pin 7 (K-Line) is present and pin 15 (L-Line) is missing then this
Radio Control for toy car Schematic Diagram
Pong Game Console
I created a simple game console that could play Pong and other games with Atari 2600 joysticks, which the Arduino would read the joystick inputs and output the data to a TV with a TVout library. I created this project just for the fact that I wanted to showcase that anyone can create their own miniature consoles to play, but also I wanted somethin
USB IR Toy
Use a remote control with your computer, view infrared signals on a logic analyzer, or capture and replay remote control buttons. USB Infrared Toy v2 has an improved IR transmitter and several new features. There`s lots of interesting infrared projects on the web. Serial port infrared PC remote control decoders have been popular for years, Ian pub
This circuit is used to sense the insertion of a penny. Before the penny is inserted, current is flowing through the detector (transistor) side of the optointerruptor, and Port M5 is HI. When the penny blocks the optointerruptor, Port M5 goes low. The hex inverter with Schmitt trigger (74HC14) ensures a clean digital signal from 0 to 5 V. The typi
Make a Remote Controlled Toy Car Circuit
The market may be full of these hi-end remote controlled toy cars, but for a hobbyists making one at home can be entirely a different experience. The article belowexplainshow to configure a simple remote controlled toy car using a ready made 4-relay remote control module. If you refer one of the previous articles you will find some data regarding
555 Timer Circuits
RC Model Toy Circuits
H Bridge 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