Can anyone explain me this circuit

In summary: It has an open collector output that can be used for pulses or square waves, but it is not meant to be used with a battery.
  • #1
gaurav_dua
5
0
http://prntscr.com/60xcwx

Thank you
circuit.jpg
 
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  • #2
This is a homework exercise?

It should be in the homework subforum.
 
  • #3
NascentOxygen said:
This is a homework exercise?

It should be in the homework subforum.
no, this is my project for school
 
  • #4
What is the circuit supposed to do?
 
  • #5
Seems a bit odd. If you connect the battery when there is no light on the LDR, the thyristor will turn on, the LED will start glowing and there will be a click in the speaker. When the LDR gets illuminated - it depends on the thyristor and the speaker (a thyristor will not turn off if the load current is large enough).
 
  • #6
NascentOxygen said:
What is the circuit supposed to do?
this is the circuit of a laser security system
 
  • #7
Svein said:
Seems a bit odd. If you connect the battery when there is no light on the LDR, the thyristor will turn on, the LED will start glowing and there will be a click in the speaker. When the LDR gets illuminated - it depends on the thyristor and the speaker (a thyristor will not turn off if the load current is large enough).
Can you explain in more detail?
Thanks
 
  • #8
gaurav_dua said:
Can you explain in more detail?
Thanks

From http://en.wikipedia.org/wiki/Thyristor :
Thyristors have three states:

  1. Reverse blocking mode — Voltage is applied in the direction that would be blocked by a diode
  2. Forward blocking mode — Voltage is applied in the direction that would cause a diode to conduct, but the thyristor has not been triggered into conduction
  3. Forward conducting mode — The thyristor has been triggered into conduction and will remain conducting until the forward current drops below a threshold value known as the "holding current"
 
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Likes zoki85
  • #9
Another thing I would like to add is the thyristor is BT-169
 
  • #10
What can you tell us about the Speaker?

Have you bought the components? How does the laser get used?
 
  • #11
gaurav_dua said:
Another thing I would like to add is the thyristor is BT-169

Look at http://www.nxp.com/documents/data_sheet/BT169_SER.pdf

A slight problem: BT-169 is not specified for DC operation.
 
Last edited by a moderator:

1. What is the purpose of this circuit?

The purpose of a circuit is to allow the flow of electric current through various components in order to perform a specific function or task. This could include powering a device, controlling the flow of electricity, or converting energy from one form to another.

2. How does this circuit work?

The specific function of a circuit depends on the components used and their arrangement. Generally, a circuit works by connecting a power source (such as a battery) to a load (such as a light bulb) through conductive materials (such as wires) and control elements (such as switches or resistors). The flow of electric current through these elements allows the circuit to perform its intended function.

3. What are the different components in this circuit?

The components in a circuit can vary depending on the purpose of the circuit, but some common components include resistors, capacitors, inductors, diodes, transistors, and integrated circuits. These components can be used to control the flow of electricity and perform specific functions within the circuit.

4. How do I read a circuit diagram?

A circuit diagram is a visual representation of a circuit that uses standardized symbols to represent each component and their connections. The symbols are typically arranged in a way that shows the flow of electricity through the circuit. To read a circuit diagram, it is important to understand the meaning of each symbol and how they are connected to each other.

5. Can you explain the different types of circuits?

There are several types of circuits, including series, parallel, and combination circuits. In a series circuit, the components are connected in a single loop, meaning that the same current flows through each component. In a parallel circuit, the components are connected in multiple branches, allowing different currents to flow through each branch. Combination circuits use a combination of series and parallel connections to achieve a specific function. Other types of circuits include AC and DC circuits, which use alternating current and direct current, respectively.

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