Tuesday, 24 March 2015

Soldering iron temperature controller

R1                15 Kilo-Ohm
P1                250K potentiometer
C1                823K, 250V
D1,D2          1N4004 or 1N4007
D3               Diac, bilateral trigger type
Q1              Triac 500V/25A, BT136

Open Loop & Close Loop Speed control for induction motors.

Open Loop Speed control for induction motors.



 In the above block diagram the Open Loop Speed control for induction motors is shown.
The system consists of the Rectifier, Filter, Three phase variable Frequency Inverter and induction motor.
The controlled rectifier converted the tree phase supply to a DC, the out put of the rectifier is a pulsing DC, there fore it is passes through the Filter, after the filter the DC voltage is feed to the variable frequency inverter ckt and the it supply to the induction.
There is no feed back in this system for the control purpose there it is called Open Loop control System.

 Closed Loop Speed control for induction motors.

           
In the above block diagram the Close Loop Speed control for induction motors is shown.
The system consist of the Rectifier, Filter, Three phase variable Frequency Inverter, Feed back system and induction motor.
The main operation of the Closed Loop Speed control for induction motor is same as of the Open Loop system, In this system simply a feed back system is introduce to control for control purpose.