Sensor Soldering Kit

Sensor Soldering Kit
Sensor Soldering Kit

Sensor Soldering Kit


Learn how to make LEDs blink while exploring how capacitors work.


This circuit is based on the properties of the Wheatstone Bridge and can be used to identify changes in resistance. Many sensors work based on a measuring a small change of resistance (temperature, pressure, light, humidity, TDS…) and the Sensor circuit allows exploration of these sensors.

Note: This item only ships to US addresses.

What's Included:

  • 2032 Battery
  • Battery Holder
  • Switch
  • 220Ohm Resistor
  • 2 x 100kOhm Resistor
  • 100KOhm Potentiometer
  • 5mm Green and Red LEDs
  • Photoresistor

The Wheatstone bridge circuit has been used for over 150 years to identify unknown resistance or measure a change in resistance. Often, Resistors R1 and R3 are known values (often identical), Rx is unknown and R2 is a form of a variable resistor that can be changed until Vb is zero. 

Resistance based sensors are commonly used as low cost means of measuring pressure, temperature, light, humidity, water quality and water quality. 

In the Sensor board circuit, R2 is a potentiometer that is used to balance the circuit.  The Sensor also uses a Operational Amplifier (OpAmp) to amplify the change in voltage when the circuit is unbalanced.  Because of the sensitivity of the circuit, it is near impossible for Vb to be exactly zero (which would be indicated by both LEDs being off.)