Tag Archives: LM358

Current Sensor Amplifier & Over Current Switch

Current sensor amplifier and over current switch project is based on ACS714-30A current sensor and LM358 Op-amp, ½ of  LM358 op-amp used as an amplifier for low voltage  and 2nd 1/2 LM358 op-amp used as comparator which provides over current TTL output, trimmer potentiometer provided to set the over current limit.  ACS714 sensor measures the current up to +/-30Amps, final output of the amplifier is 235mV/1A, and normally over current output is High-TTL, its goes low once the current over shoot than a set point. Circuit requires 5V DC and 40mA, Onboard LED indicates the power. Resistor divider R1, R3 provides bus voltage output for micro-controller interface to measure the bus voltage, choose appropriate value for R3, R1 as per your application and bus voltage, it’s should be less than 5V DC.

Current Sensor Amplifier & Over Current Switch – [Link]

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 2nd 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

Simple Pressure Sensor Amplifier & Over Pressure Switch – [Link]

Heat Activated Cooling Fan Controller

002

Heat activated cooling fan controller is a simple project which operates a brushless fan when the temperature in a particular area goes above a set point, when temperature return normal, fan automatically turns off. The project is built using LM358 Op-amp and LM35 temperature Sensor. Project requires 12V DC supply and can drive 12V Fan. This project is useful in application like Heat sink temperature controller, PC, heat sensitive equipment, Power supply, Audio Amplifiers, Battery chargers, Oven etc

Heat Activated Cooling Fan Controller – [Link]

Sound to Light Effect

SOUND-TO-LIGHT-EFFECT-PIC

This project will turn your favorite music into light effects, a microphone picks up the sound and gives  light effects with 6 Red LEDs, ideal for creating fun atmosphere at parties & discos. Supply 9V-12V DC.

Features

  • Supply 9V-12V DC (PP3 9V Battery)
  • On Board Preset for Gain Adjust
  • 6 On Board LEDs
  • On Board Condenser Microphone
  • SMD based small Board
  • PCB Dimension 45.72 X 28.58 MM
  • CN1 Supply Input
  • PR1 Sensitivity Adjust

Sound to Light Effect – [Link]

LPG Sensor Alarm

Circuit_Schematic

sameer @ sgprojects.co.in has build a LPG gas detection circuit based on LM358:

LPG gas detection project’s main idea is to implement the security system for detecting leakage of liquid petroleum gas in closed environment. In this project gas leakage is identified by using MQ6 gas sensor. A simple circuit with an Op-Amp IC is powered by a step down transformer and finally the alarm produces on detecting gas.

LPG Sensor Alarm – [Link]