4 Digit Alarm Keypad
Posted on Apr 18, 2012
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.....
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This stereo mixer has two mono mixers and a modification to the microphone inputs. When a...
I originally wanted to call it Chimera , but then I remembered there`s already a synth company...
When mains is absent, relay RL2 is in deenergised state, feeding battery supply to inverter...
Generating long delays of several hours can be accomplished by using a low frequency oscillator...
In this picture is everything you will need to make a self running power supply. The input is a...
A source code for a very simple PIC based digital timer. The actual hardware of the project isn`t...
TDA7560 is a 4 x 50 watt quad bridge car audio amplifier. The inputs are compatible with TDA7560...
This up/down timer was designed to control a power antenna on a late-model vehicle. Normally,...
Shown for the human biological signals preamplifier circuit. In the medical equipment often need...
A chopper circuit shown in FIG. The circuit uses a high-performance op amp device MC33171...
An innovative current detection method, eliminating the power loss of the sense resistor in...
As shown in Figure it is a temperature compensated with a negative voltage to follow the...
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