Type

Contact Person

Age Range

Big Ideas Of Science

Languages

Booking Required

No

Registration Required

No

Works Offline

No

Description

IoT Power Control provides remote access and control of the circuit that can control power of a small electric lamp with low AC voltage power supply using three different control circuits:

  1. Thyristor - positive half period control of turn ON point / moment
  2. Triac - two half period control with independent setting of turn ON point / moment for positive and negative half period
  3. MOSFET N and P type transistors that separately control positive (N) and negative (P) half period with main difference from triac that conduction can be stopped before AC voltage drops to zero, as they are voltage controlled elements

IoT means that it is implemented with Arduino UNO controlling the triggering of power control elements, while the network access, web server and serial USB communication with UNO card was implemented with NodeJS WebExpress / Sockets.IO / SerialPort running on Raspberry Pi 3B+.

Experiment management includes following:

  • Status button that refreshes current Experiment status
  • Chart button refreshes both the current Experiment status and voltage / current chart display
  • Mode button applies selected control mode from drop down list: thyristor / triac / MOSFET
  • On button turns on the applied AC power (current flows)
  • Off button turns off the applied AC power (no current, voltage applied)
  • Set button sets the selected item in drop down list and applies the select value from the numeric drop down list

Explanation of drop down list items for set button

  • Positive start defines start point / moment during positive half period for thyristor and triac. Value of 50 corresponds to the middle of positive half period. Notice: 0 corresponds to the beginning, but should be at least 4 or 5 for the algorithm to work correctly
  • Negative start defines start point / moment during negative half period for triac. Value of 50 corresponds to the middle of negative half period. Notice: 0 corresponds to the beginning, but should be at least 4 or 5 for the algorithm to work correctly
  • NmosFetStart defines start point / moment during positive half period for MOSFET. Values are order numbers of samples that are on horizontal axis and can start from 0.
  • NmosFetOn defines length of conducting in units of samples.
  • NmosFetOff defines length of non conducting in units of samples.
  • NmosFetStop defines stop point / moment during positive half period for MOSFET. Values are order numbers of samples that are on horizontal axis. Between NmosFetStart  and NmosFetStop periods of conducting defined by NmosFetOn and periods of non conducting defined by NmosFetOff follow in sequence.
  • PmosFetStart defines start point / moment during negative half period for MOSFET. Values are order numbers of samples that are on horizontal axis and can start from 0.
  • PmosFetOn defines length of conducting in units of samples.
  • PmosFetOff defines length of non conducting in units of samples.
  • PmosFetStop defines stop point / moment during negaitive half period for MOSFET. Values are order numbers of samples that are on horizontal axis. Between PmosFetStart  and PmosFetStop periods of conducting defined by PmosFetOn and periods of non conducting defined by PmosFetOff follow in sequence.

Screenshots

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