Before applying power, check for shorts on the board. This design runs from a FIVE volt supply, connecting it directly to a 12 volt supply will kill it for certain. The current drawn is very small, in the region of 70mA so connect a small 5V regulator in line with the supply if you intend to use a 12V power source. For the prototypes I used a stan
Click here to download the full size of the above Circuit.
dard 7805 regulator on a 2cm square copper sheet and even after running for two days it was barely warm to touch. When you are happy that the current consumption is OK, measure the voltage between ground and each of the outputs, it should be less than 0. 5V. If all is well you can connect a monitor to the video and audio outputs then put the unit in "self-test" mode by pressing the "Chan A both" and "DTMF" function keys simultaneously. You should hear alternating high and low pitched beeps at about 1 second intervals. Next, connect some audio and video sources to the inputs, in self-test mode the inputs are selected in sequence so you should see and hear the sources being selected one after another. Channel A and B sequences are staggered so you can confirm their independent operation. To exit "self-test" mode you can either switch the power off and on again or press and hold the "Chan B both" and "Antenna select" keys together until a rapid beeping is heard. You can release the keys as soon as the beeps start and after a few seconds the unit will initialise itself to its newly powered up state. The design described here is for a compact, low-cost signal router that can feed any of eight audio inputs and eight video inputs to two pairs of outputs. It also includes a DTMF tone generator and an automatic antenna selector circuit. All the functions are controlled from a pair of keypads, the function keypad decides on which...
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.....
characters left: