The following diagram is the circuit diagram of 20W power amplifier which build based tube component EL34. EL34 is very famous tube and great for power tube amplifier. The circuit above is complete circuit contains tube amplifier circuit di....

This circuit has an advantage in that almost all of the energy in the collapsing magnetic field of L2 is transferred to C2. Where as in a normal Joule thief some of this energy is returned to the battery. This is a result of the resistor VR2 preventing rapid....

I have an automotive relay (from a scan of a workshop manual I`m afraid) which is rather more complexly wired up than the relays I`m familiar with. In this diagram: B/G - holds high if another condition is met (engine temp too high), to prevent the relay....

Many households are still graced by tube-type television sets. If you want to connect one of these large tellies to your stereo system to improve the soun....

A voltage to frequency converter with a control range of 1:1000 can be easily constructed by using the IC TSC9402. The given component values in the circuit produces a conversion factor of 1kHz/1V. The input voltages from 10 mV up to 10 V are converted to....

Using an inductor inline and a decoupling capacitor it`s creating essentially a series LC circuit. Now one of the properties of LC circuits is they have a resonant frequency. I modeled a LC circuit with an attached purely resistive load to simulate what the....

As part of the DBS 800 System, this Audio signalling processor will provide an inband Tone signalling facility for PMR Radio systems. Signalling systems supported include Selcall (CCIR, ZVEI I, II and III, EEA), 2-Tone Selcall and Dual Tone Multi-Frequency....

Here is a simple tester for checking the basic operations of an infrared remote control unit. It is low-cost and easy to construct. The tester is built around infrared receiver module TSOP1738. Operation of the remote control is acknowledged by a tone from....

The Slave Flash Trigger is switched on/off by pressing the push button. When switched on, one to three flickers of the indicator lamp signalizes the programmed mode. One flicker determines that the flash will be fired at each flash. Two flickers indicate....

You can easily build an infrared illuminator yourself at home with a little effort. You should have basic electronics knowledge on order to attempt this simple IR illuminator project. There is nothing difficult in this circuit. I have used 68Ohm and 1 Watt....

Here is a solar powered Flasher to scare away the nocturnal animals like bats and cats from the farm yard or premises of the house. The brilliant multicol....

Here is a simple technique for measuring frequencies over quite a wide frequency range and with acceptable accuracy limits using a PC. It follows the basic technique of measuring low frequencies, i. e. at low frequency, period is measured for a complete wave....

The P5 design uses only eight 74HC/AC240 chips which are all octal inverting buffers. Each 74HC/AC240 chip has two groups of four inverters each controlled by a tri-state enable pin (pin 1 and 19). The 74AC240 chips (U1-U5) are used as H-bridge style motor....

This circuit is selective for the tuning adjustment between two closely spaced tones audio. The frequency is dependent on the selective value capacitors and resistors in the feedback circuit between the collector and base of Q1. With the values shown, the....

It can set delay time according to the voltage Us and resistor R. In the circuit, S1 is the the discharge switch of capacitor C. When the switch S1 is closed, the stored charge on C will be released through S1 to ensure the accuracy of the delay time the....

This improved infrared detector is specifically intended for use with commercial IR remote control handsets. This little circuit is useful for quick go/no-....

The LA4165M Recording-Playback IC combines the functions required to design the recording and playback systems and Motor Control circuits for micro- or standard-cassette tape recorders into a single chip. Functions provided include Automatic Audio input....

He only contributes with 3. 2nV/ HZ of noise tension and 0. 45pA/ HZ of current noise to the circuit. To minimize the noise of other sources, R3 it is configured for 100 ©. That generates tension of noise additional of only 1. 3nV/ HZ. R1, R2, c1, and c @....

For any robot to perform the tasks it is assigned, a controller is required. The controller may be mechanical, electrical, electronic or a combination of these. It is the brain of the entire system and gives the robot its intelligence. Additional....

The LM1875 amplifier delivers 20 watts into a 4 © or 8 © load on ±25V supplies. Using an 8 © load and ±30V supplies, over 30 watts of power may be delivered. The amplifier is designed to operate with a minimum of external components. Device overload....

This article is copied from replica sites to here in order to have a local and long living copy at hand. It seems like had radical rework done to it sometime in 2006 and original copy of this article disappeared. When discussing SSB transceivers, the first....

The circuit uses AC mains voltage and otherhigh voltages that can cause injury or death. The 125 is a basic heterodyne configuration, in which the outputs of two similar radio-frequency Colpitts oscillators are fed to a mixer, producing their difference....

The artwork style of the opamp and of the meter face both suggest that is is an ACC design and is from an old issue of ACC Notes. I have credited it as such. I scanned the second image and wrote the text below from scratch. If anybody can locate the original....

Hello, everyone, new kid on the block here After some tube amp reparations, fixes and minor upgrades (re-capping, fixing bias problems, various....

Circuit The circuit diagram provided is a triac - diac electronic fan regulator that would reduce your power usage of electric fans even in slow speeds. A normal resistor-inductor fan regulator heats up to waste eneegy when the fan is running with lowers....

This circuit arose from the need of the author to provide a 5 V output from the 24 V battery of a solar powered generator. Although solar power is essentially free it is important not to be wasteful especially for small installations; if the battery runs....

Yesterday I was triyng to read the infrared impulses from my electricity meter. The phototransistor I`m using, can see the IR from all the remotes in the house. but doesn`t read the blink from the electricity meter. I can see the IR blink of the meter with....

A circuit to extract and measure the modulated carrier of an Infra Red remote control. Note that the circuit does not physically separate control pulses from modulation, but amplifies the completereceived signal allowing the waveform to be displayed ideally....

My neighbor`s drill charger stopped working. I found that the primary wires in the transformer were non-functional. This charger had a very simple design. It used a transformer, followed by a diode bridge and a larger resistor. The power supply indicated it....

This circuit takes signal (doppler) from a radar,un, amplifies and limits it, and feeds the frequency into a counter (U4) and display circuit (DISP1, DISP2,U5,U6). Counter calibration is set by clock circuit U2B. Calibration is obtained via R21 and R22. R21....

Vacuum-tube or electronic voltmeters make use of some of the unique characteristics of electron tubes, and so are available in many types. They are available for measuring direct, rms, average or peak voltages. Of the many types available, only the simplest....

I don`t believe it was ever intended to be powered off a 9V battery. They`re feeble! Under 2 hours with an Alkaline, or....