Of particular interest to us are 12 Volt DC powered PIR sensors and associated circuits since these can be powered directly from a 12 Volt battery which is in turn charged by wind, solar, or other renewable energy sources. In this article we will look at the ways in which the excellent low current consumption Honeywell IS-215T* 12 Volt DC PIR sensor (available in the REUK Shop ) can be
Click here to download the full size of the above Circuit.
used by the renewable energy enthusiast for lighting, security, and other motion detection systems. There are many other home security PIR sensors from other manufacturers which have the same mode of operation as the Honeywell unit, so the following circuits and details will still be applicable with those. When the cover of the PIR Sensor unit is popped off it appears as shown below. A row of terminal strip at the top right of the circuit board is used for making the necessary connections - two connections to provide power to the unit (labelled + and -) and two for the internal relay (labelled C and NC). The `C` is short for Common, and the `NC` for Normally Closed. The most important thing to note about the vast majority of home alarm system PIR sensors is that they output a HIGH signal when motion is NOT being detected, and no signal at all when it IS being detected. Why are they designed this way Because if there was no signal at all when motion was not being detected, a burglar could simply cut the cables leading into the security alarm controller, and then when the signals went high when a PIR detected motion, the controller would not receive those signals and the alarm would not be triggered. With a high signal when motion is not detected, if any cables are cut or if motion is detected no signal will get to the controller and the alarm will be triggered immediately. The `C` and `NC` screw-in terminals on the PIR...
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: