SIMPLE PRESSURE SENSOR AMPLIFIER & OVER PRESSURE SWITCH

The pressure sensor amplifier built using LM358 op-amp and MPXM2051GS pressure sensor from NXP semiconductor.  The circuit provides 4V output for full scale pressure input 0-7.5PSI.  One op-amp is used as amplifier and 2^nd op-amp is used as comparator to provide an output at set value that can be used as over pressure switch to control a pump or solenoid.  This is a low cost general-purpose circuit for those applications where +/-3% performance is acceptable. Multi turn potentiometers are provided for Offset, span adjust & over/under Pressure set point to control output devices like solid state relay, Pump, and solenoid.

Features

• Supply 12V DC
• Pressure Sensor range 0-7.5PSI
• Output 0-4V (Approx.)
• PR1 Multi-Turn Potentiometer Offset
• PR2 Multi-Turn Potentiometer Span Set
• PR3 Multi-Turn Potentiometer Comparator (Switch) output Set
• D1 Power LED
• CN1 4 Header Connector Outputs & Supply Input

SCHEMATIC

PARTS LIST

CONNECTIONS