Smoke-detector


Posted on Dec 16, 2012

This smoke detector uses a MEM 817 p-channel enhancement mode MOSFET as its buffer amplifier. Operation of the sensor is based on a decrease in the current when smoke enters the chamber, thereby causing a negative voltage excursion at the gate of the buffer MOSFET.


Smoke-detector
Click here to download the full size of the above Circuit.

Quiescent voltage values at the output of the chamber vary from about -4 V to -6 V, and detection of smoke will result in an excursion of about -4 V. The MOSFET is connected as a source follower.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

60W Bass Amplifier and Preamp
Litter Box with 12V pc fan
30m Band Receiver
Lamp Dimmer schematic
Light circuit diagram: Audio Graphic Equalizer Circuit Using Op Amp
Motorola DSP Receiver
cdmp3 cd with cdroom circuit diagram
IR Music Transmitter and Reciever
800 W soft start light dimmer
Optical attenuation control circuit



Top