Pendeteksi Aliran Udara

This simple circuit uses an incandescent lamp to detect airflow. With the filament exposed to air, a constant current source is used to slightly heat the filament. As it is heated, the resistance increases. As air flows over the filament it cools down, thus lowering it's resistance. A comparator is used to detect this difference and light an LED. With a few changes, the circuit can be connected to a meter or ADC to provide an estimation on the amount of air flow.

Obstruction Detector With 12C508 IR

Description

This project is inspired by the DPRG IRPROX project. They have a pretty good PCB layout and idea. I would like to thank them for posting their project for all of us to see and learn from, I wouldn’t have started PIC programming without them, or at least not nearly as quickly come up to speed! The pinout on my board allows either a five-wire or a four-wire connection to be made the former uses a disable line if desired. You can also put in a resistor or use a trimpot to adjust range. The trimpot locations are very generic, most pots will fit. Be careful not to adjust pot to 0 ohms!

Proximity Detector Circuit Based 555 IR

Description Sometimes you want a simple solution to a problem and you don’t mind if your main controller has to do the work. This IRPD requires the main robot processor to choose which side to look at, and requires it to “debounce” the results for reliably operation. But, it still works really well without any complex program code. The NAND gate is a standard 74LS00 that you can get anywhere – even Radio Shack, same with the 555, IR detector (RS Everlight or Sharp GP1U58Y) and IR LEDs can also be gotten at Radio Shack. Parts are easy to find and simple to connect. This does not require any fancy wiring or parts placement. Make sure that you use a .1uf bypass cap next to the 555 and next to the IR demodulator. Tweak the 2K pot until you have 38KHz, if you have a ‘scope, this is a 1/38,000 period, or about 26.3us. If you are using a Parallax Basic Stamp II for your robotic controller, you can feed the output of the 555 in an I/O port and measure the frequency very easily. The code to do this is below. It assumes that you are using port 7 as the 555 input port.

Smoke Detector for Fire Alarm

This is a simple fire alarm circuit based on a LDR and lamp pair for sensing the fire. It uses a very simple approach to detecting smoke in the air. The alarm works by sensing the smoke produced during fire.The circuit produces an audible alarm when the fire breaks out with smoke.
This probably isn’t an ideal approach given that ambient light levels are likely to cause false alarms, however it is an interesting experiment. Just please don’t set any fires while experimenting. And please don’t rely on it as a replacement for a real fire alarm device.

Lightning Detector Circuit

This Do-it-yourself lightning detector circuit can be a especially sensitive static electricity detector which can supply an early warning of approaching storms from inter-cloud discharge properly prior to an earth-to-sky return strike takes location. An aerial (antenna) formed of the brief duration of wire detects storms inside a two mile radius. The circuit emits an audible warning tone from a piezo buzzer, or flashes an LED for each discharge detected, providing you advance warning of impendig storms so that precautions may be observed.