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
Musical & Effects Circuits
Musical & Effects Circuits
Musical Doorbell Circuit
This featured circuit is a musical doorbell. After the button S1 is pressed, a short melody is played. When the button is pressed many times in rapid succession or pressed longer, a different melody is generated and the melody plays longer. The circuit works this way: when the button S1 is activated the inputs of U3 and one input of U1 switches...
Music Bell with In / Out Indicator
A robot is an automatically guided machine, able to do task on its own. Another common characteristic is that by its appearance or movements, a robot often conveys a sense that it has intent or agency of its own. The word robot can refer to both physical robots and virtual software agents, but the latter are usually referred to as bots. There is n
Discolight effect with bass beat control using PIC
The PIC can control the motor after every beat or its possible to bypass some beats. It can be done by pushbuttons. Rotation speed and rotation length can be adjusted too. Settings are limited between values to prevent possible register overflow-underflow. These values are saved in EEPROM so after shut-down the settings dont lost. A beat consist o
This circuit uses a couple of Op-amps to produce an interesting sound effect. The left hand CA741 is wired as a standard astable and produces the timing pulses, controlled by C1, R2 and VR1. The output is fed via C2 to the second op-amp and is also direct coupled via the zener ZD1 to Q1. The right hand CA741 is configured as an integrator, its pur
The aim of this design is to reproduce a Combo amplifier of the type very common in the `sixties and the `seventies of the past century. It is well suited as a guitar amplifier but it will do a good job with any kind of electronic musical instrument or microphone. 5W power output was a common feature of these widespread devices due to the general
Hey! It`s another ESQ-1 repair thread! I got an ESQ-1 tonight for a very good price, and I totally expected it to have a few issues. And it`s got them..
Circuit Bending a Digitech RDS Time Machine
Here`s one for anyone else out there who likes to tinker; this is a fun project with a low likelihood of you destroying your unit. That said, you..
This amp had hum and nosise. So I added cpacitors at power supply, but Voltage was high. There was spark at final tube socket pins. So I pulled off capacitors.
Aussie Guitar Gear Heads
Sound Effects Generator 2 circuit
All sound effects are generated internally by the HT2884 IC. Power is a 3 Volt battery, but the IC will work with any voltage between 2. 5 and 5 Volts. Switch S1 is the on / off switch. The output at pin 10 is amplified and drives a small 8 ohm loudspeaker. Pressing S3 once will generate all the sounds, one after another. S2 can be used to produce
Boss DD-2 Digital Delay Guitar Pedal Schematic Diagram
The DD-2 is one of the best digital delay pedals and actually sounds very analog! The pedal was sold from 1983 and it did officially go out of sale 1986 but it was relaunched without changes as the DD-3 (later versions of the DD-3 use a different design). The circuit is built around the RDD63H101 IC and a 12 bit A/D converter producing a flat freq
Boss DM-2 Delay Guitar Pedal Schematic Diagram
There are at least 3 different versions of this circuit. The first DM-2 version was using the MN3005 BBD and the MN3101 Clock Driver IC (PCB marking: ET5214-510). Later they changed the clock driver to MN3102 and the BBD to the low current version of the same circuit, the MN3205 (PCB markings: ET5214-510A an
Boss GE-7 Equalizer guitar pedal schematic diagram
The Boss GE-7 Equalizer pedal adjusts the harmonic contents of an instrument in 7 separate bands ranging from 100Hz to 6. 4kHz, with a boost/cut 15dB per band. The additional Level control knob helps you to set a different volume for normal and effect sound (or to use the pedal only as a gain booster).
Boss SD-1 Super OverDrive guitar pedal schematic diagram
The Boss SD-1 Super OverDrive is a pedal with a simple design, using only one dual operational amplifier (uPC4558C) and 6 transistors, with an asymmetric overdrive circuitry for a classic, natural tube amp growl. It generates the warm distortion of an overdriven tube amplifier while maintaining the subtle nuances of a guitar player`s picking techn
Electronic Canary Circuits
This circuit is a modified Hartley oscillator with a couple of extra components included. The transformer is a small audio transformer, type LT700. The primary is center tapped with an impedance of 1Kohms at 1KHz. The secondary has an impedance of 8 ohms. The inclusion of R1 and C1 give this oscillator its characteristic "chirp". As the 100u capa
A series resistor, and a bypass capacitor along with a zener in parallel with the hall sensor to clamp transients that still get through. I use hall sensors here at work on a daily basis. After 15 years of working with them, I know that they`re generally robust, but do fail under certain conditions and I`m well versed in what they are. Want to...
Analog Laser Guitar Hero
Above is the schematic of one oscillator circuit. In technical terms the oscillator is a Schmitt trigger relaxation oscillator. Above you`ll also find..
Arduino Guitar Pedal
Start to build the circuit as pictured in the schematic. To see the schematic larger, click the little i in the upper right-hand corner of the image..
Blinking LEDs to Music
This is a fairly simple project for anyone with some electronic skills. Plug this circuit into an audio source and the LEDs will blink to the rhythm o..
MONSTER Musical Tesla Coil with a Microcontroller
Perhaps the trickiest part in building a solid state tesla coil is the bridge or switching circuit. The bridge switching circuit is the heart of t..
Turbo Sound effect circuit for your non turbo car
The circuit schematic is straightforward, I`ll not try to give information about assembling and testing circuits, there should be lots of instructable..
Monitoring water usage with Hall effect sensor and Arduino
This is a fairly simple schematic of the amplifier and filter. At the core of the circuit is an LM124 op-amp running in an inverting configuration. Th..
LED Light Show and Audio Amplifier all in one
The hardware within this circuit involved a Picaxe 18M2 IC which is the programmable micro-controller in my design which can be programmed using a PC,..
Tube tester collection
This is an experimental tube, that never made it. It was made by one of the Engineers of EI in Serbia, just out of interest. It was an idea of Mike Matthews from new sensor, and the tube was based on the PL519, and had indeed the characteristics of a 300B, and full 40 Watt. So it`s not the history of the 300B, but almost. The tube was to
The meter has only one scale (0. 150) but this also used for 0. 75 and 0. 30. This is such a pain, and all people use a calculator with it. I made a new meter scale for it, with all ranges. This improves the comfort so much New Meter Scale for your L3-3! Due to many requests, this new meter scale is for sale. This is on an opaque sticker foil....
YAMAMOTO PANEL METERS
Guitar Patch Cord
The PhoneAxe is an original design by the author of a passive filter network built into a 1/4" phone plug/coaxial cable, and is designed to allow electric-guitar matching to the magnetic-phonograph input on common hi-fi amplifiers. Most guitar amplifiers have "high input impedance" typically greater than 200 kohms. The reason for this is that the
I burned out some resistors on the circuit board of my Roland
Burned out some resistors on the circuit board of my Roland KC-300 amp and they are so black that I can`t tell what they are. What kind of resistor is R82, R83, R85, R92, and R93 If R92 and 93 continue to get really hot. you may have something pulling too much current. I would suspect IC10, or transistor Q6 and Q7 in the headphone circuit....
Hall Effect Sensor Circuit
The hall effect sensor we will use in this circuit is an A1302 hall effect sensor manufactured by Allegro. This IC can detect magnetic fields. We will then connect this IC to an arduino, so that we the arduino can read the voltage output by the A1302 and we can display the readings to the computer screen. When a magnet is placed in the vicinity of
60 Watt Guitar Amplifier
This design adopts a well established circuit topology for the power amplifier, using a single-rail supply of about 60V and capacitor-coupling for the speaker(s). The advantages for a guitar amplifier are the very simple circuitry, even for comparatively high power outputs, and a certain built-in degree of loudspeaker protection, due to capacitor
Electric Guitar Preamplifier
Here is the circuit diagram of a guitar preamplifier that would accept any standard guitar pickup. It is also versatile in that it has two signal outputs. A typical example of using a pick-up attached to a guitar headstock is shown in Fig. 1. The pickup device has a transducer on one end and a jack on the other end. The jack can be plugged into a
The aim of this design was to reproduce a Combo amplifier of the type very common in the `sixties and the `seventies of the past century. It is well suited as a guitar amplifier but it will do a good job with any kind of electronic musical instrument or microphone. 5W power output was a common feature of these widespread devices due to the general
Audio Filters Circuits
Audio Amplifier Circuits
Audio Oscillator Circuits
Audio Mixer Circuits
Audio Equalizer Circuits
Audio Tone Balance Circuits
Beeper Buzzer Circuits
Vacuum-Tube Valves 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