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
Meter Counter Circuits
SDR Soundcard Tester
The key to using a soundcard successfully in digital signal processing or digital radio applications lies principally in the characteristics of the soundcard itself. This applies in particular to SDR (software de ¬ ned radio) programs that turn your PC into a top-class AM/SSB/CW receiver, assuming your soundcard cooperates. If you want to experim
Phone Line Polarity Checker
Do you suspect your broadband speed (DSL) is slower than it should be It could be as simple as incorrect polarity in your phone wall socket. Build this very cheap, very simple device to find out whether you need to change your wiring! It might not seem that telephone line polarity is important, since the ring and voice signals sent over telephone
1.5v to 9v battery tester
Here the circuit diagram of DC battery tester designed by Matthew B. This circuit can be used to measure DC battery from 1. 5V up to 9V. Component Parts List: R1 = 18K Ohm R2 = 240 Ohm R3 = 8. 2K Ohm R4 = 3K Ohm R5 = 10 Ohm M1 = Panel Meter (Anyone will. This LAN tester circuit originally designed by Vassilis Stergiopoulos. This LAN tester circuit
lan tester circuit
This LAN tester circuit originally designed by Vassilis Stergiopoulos. This LAN tester circuit optionally has two designs. The first design is built based 2 main ICs that are timer IC555 and decade counter 4017. The second design is based microcontroller chip ATtiny2313 (the other kind of microcontroller should be work). The first design circuit (
Remote Control Tester
Remote control tester circuit diagram. The tester is designed around infrared receiver module TSOP1738. Operation of the remote control is identified by a tone from the buzzer. The circuit is sensitive and has a range of about 5 metres. The integrated IR receiver detects, amplifies and demodulates IR signals from the remote control unit. The piezo
Latching Continuity Tester
Latching Continuity Tester. Source: Eldon L. Knight, Tony van Roon A continuity tester is a must on every service bench for testing cables, pcboards, switches, motors, plugs, jacks,.
Off line Telephone tester
Off line Telephone tester. Here is a circuit of an off-line telephone tester which does not require any telephone line for testing a telephone instrument. The circuit is so simple that.
Motorcycle and Car Battery Tester Circuit
Going camping nowadays involves demography lots of cyberbanking accessories whether for day to day active or for fun and entertainment. Most of the time a answerable advance acerbic array and a ability inverter would be acclimated to ensure a calmly organized anniversary area alluringly the adult and the accouchement affably use their electric and
Attiny2313 based LAN cable tester
Vasilis Stergiopoulos has built a RJ45 LAN cable tester. The circuit was originally designed to use a 555 and 4017 IC, but Vasilis has published the schematic and source code in assembly for using the Attiny2313 instead. The Attiny2313 produces successive outputs at port D, where the LAN-cable is connected. If a straight cable is connected between
The food salt salinity tester meter circuit
I dont claim circuit can test all bad mosfets or all fault mosfet conditions. If mosfet is working it will operate in the astable multivibrator circuit causing the Led to flash.
Simple DIY Cable Continuity Tester
This simple cable tester can be used to check 2 wire cable such as coax cable, telephone cable, audio cable and etc. Power the circuit using 9V battery. Plug in the cable and push "TEST" button. The dummy resistor is connected to the end of the cable which has 75ohm resistor inside. The tester will show only 3 conditions, "SHORT", "OPEN" and "GOOD
Digital High/Low Logic Tester Circuit diagram
When the input signal is logic 1, the display shows `H` and the loudspeaker emits a note which is an octave higher than the `low` tone. Operation of the circuit can be seen from the circuit diagram in figure 1 and the truth table in figure 2. When the input signal is 1, transistor T1 conducts taking the input of gate N2 above the trigger threshold
Charge the battery capacity tester and realize the scheme
The battery capacity is the important index of weighing battery quality. There are many methods in the volume test of the rechargeable battery. Can be according to the discharge curve of the battery, carry on short time and discharge, thus so rough as to the battery capacity happen. The advantage of this kind of method maximum is fast, but the dis
The small resistance tester based on C8051F005 one-chip computer is designed
We have adopted the one-chip computer, utilize the advantage of the one-chip computer to design this survey meter. This survey meter can read out the resistance quantity measured from LCD display screen directly, the measurement limit is 10 2. 9999k, can store the data tested at the same time, then is sent into the upper computer by the serial...
LAN RJ45 Cable Connection Tester
Here`s a very simple, but practical circuit, which is used to check the type of LAN cables (straight or cross) as well as possible faults. So we use a unit that has 8 outputs, each one of which produces a pulse successivly. Only one output can be high at any time. Then we use two rj45 connectors and we apply the pulses to the 8 pins of one connect
Ultimate Continuity Tester Hides Many Tricks Up Its Sleeve
At the time, I wanted to build The Ultimate Continuity Tester, and I established a wish list of all the features I required: A real continuity tester. Too many multimeters and sounders react at resistances as high as hundreds or even thousands of ohms, which makes them practically us
DTMF Receiver IC MT8870 Tester
Today, most telephone equipment use a DTMF receiver IC. One common DTMF receiver IC is the Motorola MT8870 that is widely used in electronic communications circuits. The MT8870 isan 18-pin IC. It is used in telephones and a variety of other applications. When a proper output is not obtained in projects using this IC, engineers or technicians need
AC polarity detection
It should at least detect 230 VAC but it would be cool/informative for future readers if the solution could work in US and EU (approximately 120 VAC to 250 VAC). I did find this (non-isolated!) circuit, but I can not get it to simulate (the simulator complains that it needs ground or the LED blinks on both halves of the wave). Most current...
Co-axial cable tester
Co-axial cable tester is used to test whether the co-axial cable is open or short circuit or good using digital IC 4001 circuit description with parts list and various project.
Quartz Watch Tester circuit diagram of quartz watch tester
Timer IC tester LM555 tester
The IC tester in this web site is specially designed for the timer IC LM555. this circuit is used for testing timer IC. circuit diagram and technique of various project .
Transistor and diode tester
Transistor and diode tester in this website is specially design for testing all kind of transistor .using diode principle diode can also be checked.various type of testing circuit you found here .
IR Remote Control Tester
circuit diagram of remote control tester
An infrared remote control tester circuit that can be made without spenting much money. This IR tester build around an infrared reciever module TSOP1738. We can observe the remote control state by listening to the buzzer sound. The circuit is very sensitive and it support a range of about 5 meters. The infrared receiver module normally rema
zener diode tester
How to build a zener diode tester
This is a circuit to test zener diodes. It hooks up to a 120V AC line and boosts the output ..
servo motor tester circuit
Here is the program to control simple servo motor in both direction. I test it today and think that i should also share it with you people so that you can also enjoy and can takebenefit. This program will rotate servo motor in both clock wise and anti clock wise direction you can modify it according to your requirement and according to your wish a
The PACO C-25 differs from my Healthkit IT-22b in that it tests both regular and electrolytic capacitors as well as using a 40Mc oscillator to enable a rough measure of capacitance using a bridge circuit. Most of the time, with vintage vacuum tube equipment, capacitor values need only be "in the ballpark" to function perfectly so a high degree...
Breath Alcohol Tester controlling
in circuit transistor checker
This simple circuit has helped me out on many occasions. It is able to check transistors, in the circuit, down to 40 ohms across the collector-base or base-emitter junctions. It can also check the output power transistors on amplifier circuits. Circuit operation is as follows. The 555 timer ( IC1 ) is set up as a 12hz multi vibrator. The output on
servo tester circuit with 555
Frequency Meter Circuits
VU Meter 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