This circuit controls a Searchlight type signal head and produces solid - RED, YELLOW or GREEN indications. The signals can be connected for NORMAL or APPROACH type lighting of the Green signal. The circuit uses a LM556 - Dual Timer IC in a complimentary output configuration to drive a red and green, bipolar type light emitting diode to produce t
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he signal`s three colours. There are two complete block signal circuits on the PCB in the photo. The circuit on the left side is wired for APROACH lighting of the Green signal while the circuit on the right side is wired for NORMAL lighting of the Green signal. Schematics for both configurations are shown below. APPROACH - Type Lighting means that the GREEN signal is on only when the block after a particular signal is showing a RED signal. The Green signal is on when Terminal GI is LOW. The YELLOW or RED input functions are the same as for Normal GREEN lighting. The next diagram shows five signal block circuits connected using the terminal blocks mounted on the circuit boards. A four conductor cable could be used to connect the individual blocks together. The signal circuits can be controlled by any device that can pass at least 1 milliamp current and shares a common connection with minus terminal of the signal circuit`s power supply. The circuit is designed for a 12 volt power supply voltage and will drive light emitting diodes at approximately 10 milliamps. Other supply voltages and LED currents can be used by changing the values of certain resistors in the circuit. - If the signal LEDs are too bright, external resistor can be connected at the circuit board`s outputs rather than replacing resistors R5 on the circuit board. The combined current from a DETECT INPUT of one block and the YELLOW INPUT from the previous block...
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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