Spy Telephone Circuit
Posted on Feb 7, 2014
Related Circuits
New Circuits
-
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.....
.
This project takes advantage from -HOLD input, which is connected to push-button P1. As long as...
The circuit provides a clean, stable square wave and it will operate on anywhere from 6 to 15...
Specificaly for the chip that is used in this circuit data are like this: Oscilator runs at freq...
The schematic diagram come from circuit: 70 W Switching Power supply with KA2S0880 IC power...
This circuit is presented as an alternative to the IR beam break detector featured in the June...
The variable frequency power supply, as the important constituent element of the power system,...
O The SA1021 integrated Radio receiver circuit is for portable Radios stereo as well as mono,...
When a gas leak occurs, a gas leak alarm must detect the problem immediately and issue an alarm....
You need to wire 8 Max6675 ics to a microcontroller. You can parallel all the clock inputs. The...
As shown for the basic connection circuit ISO120/121 signals and power supply. Each power supply...
FIG switching solenoid driver circuit, wherein the device chip U8 is 74123, the device is a solid...
characters left:
Watson Oct 10, 2017