Universal Sensor.
This DIY kit will help with your soldering skills, while you learn about the standard 358 opamp IC. The kit teaches you how the IC can be used to get a sensor to switch a relay ON at an adjustable set point. Where you have the choice of an NTC or LDR sensor as an input device. It intergrades a voltage-follower NPN transistor and Zenner as a stable voltage regulator. So you can power it with a wide voltage range and no need to worry about the voltage varying on the ref point of the opamp.
This universal sensor board can be set up as a daylight switch or Temp switch
by only using an LDR or NTC as our sensor for the application this will switch a Relay on at a set value selected using a pot.
We also have a Uni Sensor PCB project with more information.
Universal Sensor Specification:
Capacitors Values: 330uF, 220uF, 100uF
Resistors Values: 10k, 1K, 220R, 10k
Variable Resistor Values: 100K
Diodes: 2x 1N4001 Diodes, 5V1 zener
Transistors: NPN TIP 120, BC337
Relay: 5V Relay
Connectors: 2x 2Pin, 1x 3Pin
LEDs: 1x 5mm LED red
Sensor IC: LM358 Sensor IC