AH3503 3503 Linear Hall Effect Sensor in Pakistan

KY-039 5V Finger Detection Heartbeat Sensor Module Detector For Arduino 1.This project uses bright infrared (IR) LED and a phototransistor to detect the pulse of the finger, a red LED flashes with each pulse .Pulse monitor works as follows: The LED is the light side of the finger, and phototransistor on the other side of the finger, phototransistor used to obtain the flux emitted, when the blood pressure pulse by the finger when the resistance of the phototransistor will be slight changed. 2.Chosing a very high resistance resistor R1, because most of the light through the finger is absorbed,it is desirable phototransistor sensitive enough. Resistance can be selected by experiment to get the best results.The most important is to keep the shield stray light into the phototransistor. For home lighting that is particularly important because the lights at home mostly based 50HZ or 60HZ fluctuate, so faint heartbeat will add considerable noise.

MQ-9 MQ9 Carbon Monoxide Gas Alarm Combustible Sensor Module For Arduino Suitable for home or factory gas leakage monitoring devices. Have better sensitivity to CARBON MONOXIDE, METHANE, LIQUEFIED PETROLEUM GAS. High quality dual-panel design, with power indicator and TTL signal output instructions. DO switching signal (TTL) output and AO analog signal output. TTL output valid signal is low. (When the output low signal is on, it can be directly connected micro-controller or relay module.) Analog output voltage: the higher concentration, the higher voltage. Four screw holes, easy positioning. Long life and stability, quick response and resume. Input voltage: DC 5?0.2V Power: 150mA DO output: TTL digital 0 and 1 (0.1 and 5V) AO output: 0.1-0.3V (relatively clean), the highest concentration voltage is about 4V. Dimensions: 32(L) * 20(W) * 22(H) mm AO ? analog signal output