4×4 Matrix Keypad Module In Pakistan

The MQ135 MQ-135 MQ 135 Air Quality Detector Sensor Module For Arduino has lower conductivity in clean air. When the target combustible gas exists, the conductivity of the sensor is higher along with the gas concentration rising. Convert change of conductivity to the corresponding output signal of gas concentration. The MQ135 MQ-135 MQ 135 gas sensor has a high sensitivity to Ammonia, Sulphide and Benzene steam, also sensitive to smoke and other harmful gases. It is at low cost and suitable for different applications such as harmful gases/smoke detection.

MQ8 MQ 8 MQ-8 Hydrogen Gas Sensor Module For Arduino H2 Alarm Detection MQ-8 Sensor Hydrogen Gas Sensor Module H2 Alarm Detection use in clean air low conductivity tin oxide (SnO2). When there is an environment in which the combustible gas sensor, conductivity sensor with increasing concentration of combustible gases in air increases. Using a simple circuit to convert the change in conductivity of the gas concentration corresponding to the output signal. MQ-8 hydrogen gas sensor of high sensitivity, the monitoring of the other hydrogen-containing gas is also very satisfactory. This sensor can detect a wide range of hydrogen gas, city gas, in particular, is a low-cost sensor for a variety of applications.

The MAX9814 is available in the space-saving, 14-pin TDFN package. This device is specified over the -40°C to +85°C extended temperature range. MAX9814 is a low-cost, high-quality microphone amplifier with automatic gain control (AGC) and low-noise microphone bias. The device features a low-noise preamplifier, variable gain amplifier (VGA), output amplifier, microphone-bias-voltage generator, and AGC control circuitry. The low-noise preamplifier has a fixed 12dB gain, while the VGA gain automatically adjusts from 20dB to 0dB, depending on the output voltage and the AGC threshold. The output amplifier offers selectable gains of 8dB, 18dB, and 28dB. With no compression, the cascade of the amplifiers results in an overall gain of 40dB, 50dB, or 60dB. A trilevel digital input programs the output amplifier gain. An external resistive divider controls the AGC threshold and a single capacitor programs the attack/release times. A trilevel digital input programs the ratio of attack-to-release time. The hold time of the AGC is fixed at 30ms. The low-noise microphone-bias-voltage generator can bias most electret microphones.