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
The potentiometer value is not critical: anything from 1 k © to 100 k © is acceptable. If you have built the "precision potentiometer" described earlier in this chapter, it is recommended that you use it in this experiment. Likewise, the actual values of the resistors are not critical. In this particular experiment, the greater the value, the bett
digital thermometer or talk I2C to your atmel microcontroller
A pre-requisite for this article is that you have the GCC AVR programming environment installed as described in my "Programming the AVR microcontroller with GCC, libc 1. 0. 4" article. If you want to avoid troubles with the installation you can of course use the AVR programming CD from When you use such an advanced device as a microcontroller
lf365 A digital thermometer or talk I2C to your atmel microcontroller
The Atmega8 microcontroller from Atmel has plenty of digital and analog input/output lines. It is the ideal device to develop any kind of measurement equipment. A pre-requisite for this article is that you have the GCC AVR programming environment installed as described in my "Programming the AVR microcontroller with GCC, libc 1. 0. 4" article. If y
Practical Data Acquisition using a Windows based Power Meter
This application note describes the design of a PC-based, 14-bit data acquisition system. It takes a system approach, includes all the necessary building blocks: analog, digital, hardware, and software. It discusses each step, testing systems separately before integrating them, and detailing pitfalls learned along the way. Many articles h
Signal Meter circuit
THE OP-AMP: The Op-Amp used for the signal meter circuit is a TL061. An LF351 works just as well, however and has the same pin layout. If you have a TL062 or similar the differing pin-outs are shown below so that you can design your circuit board successfully. The diagram above shows the pin layout of the TL061 and some alternative op-amps that ca
Capacitor meter circuit
Digital Capacitance Meter with RS232 interface circuit
Unlike almost all SMD resistors, the SMD ceramic capacitors are not marked with their values. To find the value of these capacitors we need a capacitance meter..
Frequency meter circuit
The input signal it is applied to a gate G and then to a counter, for a precisely period of time After this period of time, the input signal it is stopped for a while and then the cycle it is repeated. In the time of break the content of counter it is transferred in buffer memory and then it is displayed. After the load of buffer memory, the con
DS1820 thermometer circuit
This DS18S20 digital thermometer provides a precision of 0. 5 °C and SCRATCHPAD it`s read at every 800ms. Capacitors C5, C6 and diodes D8, D8 makes a voltage doublers which power the lcd panel. The DS18S20 temperature sensor it`s wrapped in a thermo contractil tube. For connection cable I chose a type used in audio (coaxial stereo) that is only 1 m
Serial Voltmeter implemented by Guino
MW0LLO RF Milliwatt Meter
This project, based on an article published in the February 2008 edition of Radcom (the magazine of the Radio Society of Great Britain) is for a meter with a 50 ohm input impedance for measuring very small RF powers. Many RF power meters become inaccurate at low powers, but this meter is able to measure down to very low levels. From a theoretical
DIGITAL THERMOMETER CIRCUIT
This circuit is composed of a temperature sensor, amplifier, V/F converter, three digit binary coded decimal (BCD) counter, time base and seven segment led displays. In addition to the 9400 V/F converter, other ICs need for this project include the LM334 temperature sensor, LF353 dual op amp, NE555 timers, 74LS00 NAND gate, MC 14553 three digit
Analog Sequential Controller Satellite SC-S Monitor Test Meter
Electronic Ammeter and Voltmeter
I found that my sprite, burdened with an extra electrical load from an electric cooling fan, just barely kept the battery charged. My intended solution to this problem is an electronic voltage regulator; however, it seems obvious that, before changing the regulator, I need some way to monitor the charging. Most meters today are digital. They...
HEI + Voltmeter Mercuiser 288 350 SBC
PC based frequency meter
The simple circuit offers no isolation, but the simplicity of the circuit combined with cost of sound cards and the fact that diodes 1 and 2 add a good measure of protection makes this circuit ideal for the average user. Notice the physical hardware includes a 20MHz crystal oscillator module. This is not required to make the circuit work, but is i
The A3008, when plugged into the same LWDAQ Multiplexer, can create bad messages in a Data Receiver ( A3018 ). Set the A3008 local oscillator to its minimum (DAC count 0) or maximum (DAC count 255) frequency to reduce the bad message rate. Even better: unplug the A3008 when you`re not using it. The RF Spectrometer (A3008) measures RF powe
EAGLE Ultrasonic Range Meter
The oscillation circuit of the transmitter was added. An oscillation circuit by 555 IC is used for a modified circuit. This is to adjust an oscillation frequency easily. Thereby, it is necessary to change the software.
Circuit explanation for Ultrasonic Range Meter
The ultrasonic signal which was received with the reception sensor is amplified by 1000 times(60dB) of voltage with the operational amplifier with two stages. It is 100 times at the first stage (40dB) and 10 times (20dB) at the next stage. Generally, the positive and the negative power supply are used for the operational amplifier. The circuit thi
Circuit explanation of Ultrasonic Range Meter unit
Electric Fence 20KV pulses for perimeter defense
An electric fence, perimeter protection circuit, designed to run on batteries, and provide configurable pulses of up to 20KV, to protect a tent perimeter against bears or other animals, out in the wild. The device uses two 555 timer circuits to generated a variable frequency, variable width pulses, that are used to drive an auto induction
DIY/Homemade Radiation Geiger Dosimeter
An efficient, stable, easy to build construction for all your radiation dosimetry needs. I started from scratch, designing a complete dosimeter unit around the Atmel Atmega8 microcontroller and a Russian Geiger Muller tube. Here you`ll see the CTC-1 tube, for high gamma doses, but the dosimeter can be used with any other tubes such as SBM-20,...
Tilt Sensor via Accelerometer Circuit
The schematic for this project is fairly large and you can see the complete schematic below. To explain what is happening here I will split it into two sections which I will call the analog and digital sections. The schemtic below (click to enlarge it) is the analog to digital conversion circuit. It has 12 comparators, 6 for the X axis and 6 for
The Accelerometer Circuit
The schematic is very simple for this tutorial. It is just a matter of wiring up the ADXL320 sensor to the PIC and the LED. The power circuitry assumes you have a battery of +5v to power the PIC. You can create your own custom circuitry for this or just use a battery array. whatever you like. The PIC is the brains of the circuit. Using the A/D`s
1929 MOPA 80 meter transmitter using a pair of 27 triodes to an 865 tetrode
This transmitter had its origins as a conventional shunt fed Hartley oscillator for 80 meters using a pair of 27 triodes connected in parallel; with 300 VDC on the plates of the 27`s, I was able to get about 4 watts output ( with decent stability ) for about 18 watts input, about 23% efficiency. Here is a schematic of the oscillator by itself: Thi
Single 10 Shunt Fed Hartley Oscillator for 80 meter CW
This Hartley oscillator was built on the remains of a single tube Hartley using a single 45. The original circuit I constructed was one that was published in a 1932 QST article by George Grammer. As it turned out, both of the 45s I had were weak, so the oscillator only would run when it was loaded very, very lightly. I did, however, have a good 10
EXPANDED SCALE DC VOLTMETER
When using an analog meter to set the output of a power supply used for testing 12-volt equipment, an expanded voltmeter scale has a decided advantage and accuracy over a linear scale. Figure 1 shows the original meter scale and the expanded scale used in this example. Eref is a 5-volt reference voltage set by the two LM236 reference diodes. Keep
80 METER CW TRANSCEIVER WITH DIRECT CONVERSION
The RF signal is split into two signals that are shifted 90 degrees out of phase (one plus 45 and one minus 45 degrees). Both are mixed to audio frequencies. The two audio signals are again shifted 90 degrees out of phase (again one plus 45 and one minus 45 degrees). When we add the two signals, one side band is in phase and added, the signals fro
VHF & UHF universal frequency meter
VCM 163 Valve Characteristic Meter Equipment
The AVO VCM 163 is one of the few tube testers (British: valve tester) being able to measure tube electrode currents, e. g. plate and screen current (fig. 1, left-hand meter movement) as well as mutual conductance (fig. 1, right-hand meter movement) simultaneously. The VCM 163 is the latest and most elaborate tube tester ever built by AVO. All volt
Frequency meter - LC measuring instrument
Feature of an offered frequency meter that he besides the main function allows to define inductance of various coils, resonant frequency of contours, capacity of condensers. The combined device which schematic diagram is shown on fig. 1 becomes the good assistant to the radio fan designer. For its manufacturing scarce details are not required, it
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
News & Articles
Keithley Bench Digital Multimeter - Review | element14 ...
Needle Tipped Multimeter Probe by thsmi - Thingiverse
Anyone recommend a good low-end multimeter ...
Power Supply Replacement for Keithley 177 from Perry ...
What is the easiest fix you've encountered from a customer ...
10 Car Diagnostic Tools for DIYers | Family Handyman | The ...
Flexible LabVIEW Flow: PSU, DC Load, Oscillosco ...
Think Surgical Field Service Technician | SmartRecruiters
No Power to Wifi Ranger | Oliver Travel Trailers
The Green New Deal isn't outlandish — it's a necessity
Tri-State Vending Association Plans First Annual Bill ...