About the article

Humidity sensor

Handy for in the bathroom

Humidity sensor
This circuit was devised by the author to automatically turn on an extraction fan in the bathroom when the humidity becomes too high. The detector circuit consists mainly of a dual CMOS timer, a resistive humidity sensor and a solid-state relay.
Downloading of this magazine article is reserved for Elektor Members only.
Already a member? click here to log in.
Relevant websites
Gerber file

CAM/CAD data for the PCB referred to in this article is available as a Gerber file. Elektor Members can exclusively download these files for free as part of their Membership. Gerber files allow a PCB to be produced on an appropriate device available locally, or through an online PCB manufacturing service. Elektor recommends its business partner Eurocircuits as the company of choice for its own prototypes and volume production in selected cases.

Download the BOM list
The BOM (Bill of Materials) is the technically exhaustive listing of parts and other hardware items used to produce the working and tested prototype of any Elektor Labs project. The BOM file contains deeper information than the Component List published for the same project in Elektor Magazine. If required the BOM gets updated directly by our lab engineers. As a reader, you can download the list here.
Want to learn more about our BOM list? Read the BOM list article for extra information.
R1,R2,R3 = 220kOhm
R4 = 1kOhm
P1 = 100kOhm trimpot, horizontal
C1,C2,C4,C5 = 100nF
C3,C7 = 1000µF 16V radial
C6 = 3.3nF
B1 = B40C1500 bridge rectifier
IC1 = 78L05
IC2 = NE556
IC3 = S101S06V (Sharp) solid-state relay
Tr1 = AC power transformer, PCB mount, sec. 2 x 6V, 350mW (Block type AVB 0,35/2/6)
K1, K2 = 2-way PCB terminal block, lead pitch 7.5mm
K3 = 2-pin pinheader for sensor connection
Sensor: Hygrosens type SHS A2 (Octopart.com)
PCB # 120463-1

We buy at:

Loading comments...