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Material Storage Level Controller Circuit

Material Storage Level Controller Circuit

The post discusses a simple material storage level controller circuit which can be used for automatically activating and deactivating a storage filling motor whenever the storage container is filled to its stipulated threshold level. The idea was requested by Mr Sladjan.

Circuit Objectives and Requirements

  1. I need help with the engine control filling storage where the material level controlled by photo resistor and a laser beam.
  2. When the photoresistor see the light it is necessary to start the engine and the fill storage until the level of the material is cut the laser beam and the photoresistor remain without light then turn off the motor and the laser beam.
  3. After a certain time interval (3 - 5 min) turn on the laser beam and check the level again at the storage material.
  4. I searched on the site, but I could not find something similar.

The Design

The material storage level indicator circuit as requested above can be built using the following simple configuration:

Material Storage Level Controller Circuit


The functioning of the circuit can be understood as given below:

When power is first switched ON, the supply powers the 555 circuit and simultaneously also switches ON the motor, and the laser through the relay N/C contacts causing a low resistance on the receiving LDR device.

The low resistance from the LDR inhibits the BC557 from conducting and the situation locks in this condition, until the space between the Laser/LDR begins filling with the relevant material.

As the material begins filling, at some point of time it reaches the threshold level between the LDR/laser communication beam, and interrupts the beam.

As soon as this happens, the LDR resistance becomes high allowing the BC557 to conduct and trigger the IC 555 stage which is actually wired as a standard monostable multivibrator circuit.

The IC 555 triggers into action and in the course activates the relay. The relay contacts change position from N/C to N/O, which instantly cuts-off power to the laser and LDR network and the motor, as requested by the user.

The situation is sustained until the set time of the monostable lapses and the relay reverts to its earlier N/C position. The circuit now attains its original standby position and activates the motor, until the storage is full again.

The proposed material storage level controller circuit can be further enhanced with an alarm indication by suitably attaching a 12V alarm circuit with the N/O contact of the relay so that whenever the storage is full, the relay disables the laser and also activates the associated alarm.

The value of C can be determined with respect to the 100k resistor from this IC 555 calculator software.


About the Author

I am an electronic engineer (dipIETE ), hobbyist, inventor, schematic/PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials. If you have any circuit related query, you may interact through comments, I'll be most happy to help!

17 thoughts on “Material Storage Level Controller Circuit”

    • Wong, please click the diagram to enlarge and you will be able to see all the parts clearly.

      all the resistors are 1/4 watt rated.

      the transistor is BC557

      if you any specific doubt you can feel free to ask

  1. sir ,sorry do you know the equality of dioda zener BZX55C ?.. in my old coffee machine there is one dioda zener BZX55C is broken. please help sir. Thanks Sir.

    • Wong, it's a zener diode, BZX55C is its series number, the actual voltage value should be just beside it, try to locate and identify that number.

  2. greating, sir i need help for my coffee machine. i want to make timer switch that i can set it from 0-60sec.
    fo exmple :
    exp 1 >

    1. i set the timer to 50 sec
    2. i push start switch ( like bell switch ) the pump will on
    3. after 50 second the pump off.

    exp 2>
    1. i set the timer for 50 sec
    2. when i push start switch ,green led on and the pump on
    3. and there is another switch that i can use to stop manualy the pump when the timer did't reach 50 sec.

    please help sir, thanks a lot sir.

    • Hi Swagatam, I made this circuit, but only works fine with a 10K resistor instead of 330K.
      It happens that when the resistance of the LDR increases slowly, do not get trigger on pin 2 of IC555, оnly when LDR resistance jumps sharply.
      Can this part of the circuit to be done with a LM741?

    • Hi Sladjan, IC555 acts like a comparator and also as a timer therefore it is more advantageous than an opamp

      I think you can try increasing the 0.22uF to 1uF or 2.2uF and then check the response

    • but LDR resistance is not supposed to increase slowly, it should increase instantly as soon as power is switched ON and as soon as the laser light falls on the LDR,

      secondly, the IC will trigger when there's no laser light on the LDR, as long as laser is focused, the IC output will be OFF.

      I think there's some confusion from your part.

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