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
555 Timer Circuits
RC Model Toy Circuits
H Bridge Circuits
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...
Melody Doorbell circuit
In all the houses exist the bells in the door. All want, they have the possibility of being possible to change the intensity, the tone of sound. With this circuit we have this possibility. With the materials round the gates, we can change the sound. For the materials that exist in the circuit the frequencies are roughly 5 KHZ and 2 KHZ. The...
Electronic Switch ON-OFF
Here we have three choices, with which we can make electronic switches that use our touch or pressing (push button). We thus exploit the very big resistance of entry, that present the gates CMOS. In the fig.1 we have two gates NAND or NOR (IC1), connected as R-S flip-flop. Just as we press the switch S1, the exit 3 it becomes [H], even it is...
8 way electronic selector / switch
The Elect. Sel. 8 is a simple circuit, with a choice of 8 sources of any sort ,of 8 independent switches. Each switch corresponding with a relay for example the switch S1 activates the RL1 e.t.c. The uses of the circuit are quite a few, choice of entrances in a sound amplifier, choice of command, in a digital circuit etc. In each entrance a...
Electronic 10 way Selector Relays
This is a circuit for alternative sources selection. It combines mechanical selection using a rotating switch S1, the electronic drive of the relays RL 1-10 and also the optical indication of the selection by the Display DSP1. The function is based on the connection of the mechanical selections into 4 Bit (BCD) code. It is managed by the proper...
Voltage window switch
A voltage window switch is in practice the basic lower window limit of this circuit is roughly 3V and the upper limit is 9V. The window range can be extended by fitting a suitable range
Wireless doorbell 300MHz
The operation of a 303MHz circuit has been covered in our project WIRELESS DOORBELL. We are not going over how the circuit works but explain the importance of some of the components and how they effect the range. The most critical component is the transistor. A quality transistor is important in the RF section and Japanese transistors are by...
Sound Controlled Switch
Described here is a very inexpensive solution to many phono-controlled applications like remote switching on, for instance, or activating a camera, tape recorder, burglar alarms, toys, etc. The circuit given here employs a condenser microphone as the pick-up. A two-stage amplifier built around a quad op-amp IC LM324 offers a good gain to enable...
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 Flasher with 555
This is a very basic circuit for flashing one or more LEDS and also to alternately flash one or more LEDs. It uses a 555 timer setup as an astable multivibrator with a variable frequency. With the preset at its max. the flashing rate of the LED is about 1/2 a second. It can be increased by increasing the value of the capacitor from 10uF to a...
Advanced LED Flasher with 555
This circuit uses three easily available 555 timer ICs. All three work as astable multivibrators. The first 555 has an on period and off period equal to 1 sec. This IC controls the on/ off periods of the other 2 555s which are used to flash two bulbs through the relay contacts. The flashing occurs at a rate of 4 flashes per second. The diodes...
Optical toggle switch with 4027
Using dual flip-flop IC CD4027 employ a 555 based monostable circuit to supply input clock pulses. The circuit described here obviates this requirement. One of the two flip-flops within IC CD4027 itself acts as square wave shaper.
Sound activated switch circuit
An infra-red or wireless remote control has the disadvantage that the small, handy, remote transmitter is often misplaced. The sound operated switch has the advantage that the transmitter is always with you. This project offers a way to control up to four latching switches with two claps of your hand. These switches may be used to control lights...
Touch Switches Collection
Touch operated switches are an attractive project for DIY electronics but they are not so common in commercial products. The reason for this is that, although there are many different ways of implementing a touch switch (leakage, hum pickup, capacitance, albedo) all of them rely on body parameters which vary a lot with the person's body, age and...
Data Switch with LED
Just to prove that transistors can also be useful in logic situations; this is a data latch and indicator which also is a data switch and has a bidirectional input/output port which can be read or switched. If the second transistor is off, a small currrent will flow via the LED, 12K and 220K to make Tr1 conduct, keeping Tr2 off. At the same...
LED Traffic Lights for Games
This schematic uses the 555 timer and the 4017 IC to drive 3 LED, to simulate the trafic lights.
555 LED flasher II
The 555 circuit below is a flashing bicycle light powered with three C or D cells (4.5 volts). The two flashlight lamps will alternately flash at a approximate 1.5 second cycle rate. Using a 4.7K resistor for R1 and a 100K resistor for R2 and a 4.7uF capacitor, the time intervals for the two lamps are 341 milliseconds (T1, upper lamp) and 326...
CMOS Toggle Flip Flop Switch
The circuit below uses a CMOS dual D flip flop (CD4013) to toggle a relay or other load with a momentary push button. Several push buttons can be wired in parallel to control the relay from multiple locations. A high level from the push button is coupled to the set line through a small (0.1uF) capacitor. The high level from the Q output is...
Toggle on off switch
This circuit toggles on and off a NE555 with a single momentary switch. Unlike a mechanical bistable relay the circuit backs to the start condition if you switch off the power supply. No relay contact is used.
Capacitive Discharge Magnetic Pulser
This is one way of generating an intense magnetic pulse. A charged capacitor is discharged through a loop shaped inductor and an intense magnetic field is generated. This circuit burns a 555 chip which is placed slightly above the loop shaped inductor (L2).
PA1B-02 page of VERON department Nieuwegein and surroundings
Information for the radio broadcast and listening amateur in VERON department Nieuwegein (A29) and surroundings.
Michael J. Rainey: July 2011
Some months ago a surprise package turned up in my mailbox. Ananonymous donor had sent me threewonderful, old germanium transistors. The2N170 and a pair of 2N107`s (all date-coded December 1956) werestill in theiroriginal plastic tube packaging. Athin booklet, Type 2N107 Transistor Circuits for Experimenters [and] Amateurs, was also included....
RCA BC-224-A - the First BC-348
The mid to late 1930s reflected a curious mixture of old and new thinking in aircraft radios, led by brilliant engineers in such companies as Aircraft Radio Corporation and RCA. The example below should endear itself to every radio amateur growing up in the 1940s or 1950s, because it was the first of the BC-348 series of aircraft receivers. A clos
TL072 op-amp configured as voltage comparator
The Maya used several calendars simultaneously. One of them called the "long count", is a continuous record of days from a zero date that correlates to Aug. 13, 3114 BC, and is more According to maya`s celender when the both the wheel of the maya celender will complete its rotation the celender would end and that would be the END OF THE WORLD One
Sanyo Tda8362 Service Manual
MODULATED PT2399 CIRCUIT
i`ve been wrapped up in Jeep repair lately as there`s some sort of issue prevent the beloved XJ from firing up. i have, however, in the meantime had some time to work through my initial modulation tests on this version of the PT2399 circuit and nail down a lot of the bugs. the initial problems were stabilizing the LFO and purging the noise from th
Add to our circuit despreading spectrum 2 identical branches more. Difference is only in phase of PN sequences given to each branch (to input of double-balanced mixer). In EARLY branch, phase of PN sequence is earlier about ½ byte. In LATE branch, phase of PN sequence is later about ½ byte than phase in ON-TIME branch. If frequency of PN generat
Electrical transformer tutorial
Afroman covers the basics of how transformers work, where to shop for step down mains transformers, and how to wire one up to mains voltages without killing yourself. European and North American wiring is discussed. He finishes up with a quick example of AC to DC conversion in an unregulated dual rail power supply. Remember to add a fuse in series
AirBorn Electronics project
Embedded system design engineers design work examples from 1990s era.
The HandyBoard drives both pads at the positive supply of the battery. When one of the motor is supposed to turn, the handyboard drives the appropriate pin at 0V. The difference between two pads makes the motor turn. The Transistors are TIP 120 and TIP 125 but could be changed for more recents ones. They are supposed to drive 5 mA continous with a
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