Repository-circuits
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This circuit may be tuned to operate over the range 87-108MHz with a range of 20 or 30 metres. I have used a pair of BC548 transistors in this circuit. Although not strictly RF transistors, they still give good results. I have used an ECM Mic insert from.... -
This is the schematic for an FM transmitter with 3 to 3. 5 W output power that can be used between 90 and 110 MHz. Although the stability isn`t so bad, a PLL can be used on this circuit. This is a circuit that I`ve build a few years ago for a friend, who.... -
The normal telephone bell, at times (specially during night when one does not want to be disturbed), appears to be quite irritating. The circuit shown here converts the loud sounding bell into a soft and pleasing musical tone. The incoming ring is detected.... -
While talking to a distant subscriber on telephone, quite often we feel frustrated when the voice of the distant subscriber is so faint that it is barely intelligible. To overcome the problem, circuit of an inexpensive amplifier is presented here. It can be.... -
This project is a 3 or more lines mixer. For more than 3 inputs you can repeat the input parts (P=10K R=22K). It powered with 9Vdc.... -
If you feel that somebody is tampering with your telephone line you might find this little circuit useful. It detects if there is another telephone connected to the line, if there is a short or an open line. Sound and a flashing light will tell you which is.... -
Small telephone bug. Listen telephone line on your FM receiver. It is self powered. Small part count. Circuit diagram, schematics, electronics project.... -
It signals that the phone is in use by lighting a red LED. When the phone is not in use, a green LED is lit. It needs no external power and can be connected anywhere on the phone line, even mounted inside the phone. 4. The ring voltage on a phone line is.... -
This nifty little circuit lets you record your phone conversations automatically. The device connects to the phone line, your tape recorder`s microphone input, and the recorder`s remote control jack. It senses the voltage in the phone line and begins.... -
This version of the Link is for those who really need a good cheap intercom that will work reliably, but without access to an outside Telco line. This could be in a pre school, a hobby farm or a small workshop or factory, where external phone traffic needs.... -
Burr-Brown DRV134 AUDIO BALANCED LINE Receiver schematic PCB/Kit anybody? I want to make a Balanced Line RECEIVER using the DRV134. Could anybody.... -
Can a 555 negative supply circuit, like the one below I pulled from another schematic, supply enough negative voltage to a LM324 and a AD736JN? I`m.... -
This might seem like a dumb question, but I`m a total newb in electronics. I built this preamp to amplify the signal from a small speaker that i use.... -
Originally Posted by Pano Like putting milk and sugar in your coffee. Next time by, your Turkish coffee comes with no sugar dave.... -
The only downside to a single opamp stage is that it inverts the signal so needs another inverting buffer to put it back again (if absolute phase is important to you). I have seen bunch of schematics with both configurations but I don`t know which one would.... -
Hi all, I am very new to this forum as well as DIY electronic circuits. I am not an electrical engineering student nor I have sufficient background (I .... -
So I needed a circuit to act as a bass boost. I ended up adapting this circuit (by ESP Sound) by excluding everything but the 35-150hz part. This.... -
Those who`ve scrutinised my PC-board layout very closely, will see that I`ve changed the design slightly from the circuit which I posted a while back. .... -
Originally posted by Justinasia What is the likely cost of the Aleph Ono, all the parts I mean? Anyone know? If it is the same as the Pearl but better .... -
A community dedicated to helping everyone learn the art of audio. Projects by fanatics, for fanatics!.... -
Hi to all I`m new in the forum or better I have used it some ago to make a diy projector!I do not know electronics so much (I`m reading books and.... -
I done some more playing with the LTspice simulation of Dxvideo`s preamp-with-DC-Servo circuit. I have been using the .four command to have spice.... -
Hi all, I am planning to make another LM4702 amp with SAP15 devices (which is published in another topic in this forum). The amp will be in non.... -
this LM4702 has found a new home in a Crown DC150 -- for some reason the driver board in the crown was fried but the power supply in good shape:.... -
Any thoughts as to how to remove RF from a point-to-point chip amp? I suddenly seem to be picking up a RF signal. It is ever so slight that one must.... -
Originally Posted by Neil Davis It`s not a sim. It`s a real measurement from a circuit that has basically the same topology as the Tripath data sheet. .... -
Does anyone know where I can get a schematic for a USB to SPDIF converter, like the ones from empirical audio. Thanks!!! I like their concept but $500 .... -
Can someone enlighten me as to why there is a LC filter on the op amp circuit. And can I do anything to it to improve the sound....
New Circuits
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This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of.... -
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.... -
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.... -
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.... -
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.... -
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,.... -
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.... -
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.... -
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.....
Popular Circuits
Agreeable, very close sound imitation Suitable for sound effects, door-bells etc. This circuit...
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oscillator is a mechanical or electronic device that works on this principles of oscillation....
There are not many AM transmitters that are easier to build than this one because the inductor is...
The project is a continuation of the 5kW Boost converter project. After a few failed attempts, I...