Hi,
this is my project and i need some help.
I have decided to use pulse width modulation of field voltage in order to change the field current and hence regulate the terminal voltage. Further, i've selected TL494 for this.
My difficulties:
1) I have to couple TL494 with a power mosfet. I've decided the switching frequency of TL 494 to be 20 KHz. The drain of mosfet would be connected to the voltage obtained by rectifying (half wave) the terminal voltage of that alternator. The source will be connected to one end of the field winding.
I require 5 A continuous current and in short duration, 6 A for 10 sec.
Kindly suggest a Power Mosfet which is easily available and cheap.
Also a proper optocoupler/pulse transformer for coupling.
2) the AVR circuitry will also be fed form the rectified terminal voltage. So i need to design a zener regulator .Kindly suggest a BJT so that the O/P of zener regulator is 15Volts, 25Watts max.(fig attatched)
I'll post the schematic soon..
PS: The AVR ahould be such that it can be used with alternators of different rating. (Max limit 5 KVA). Also, i need the cost to be low. Current AVRs available in India cost Rs. 2000 approx.
this is my project and i need some help.
I have decided to use pulse width modulation of field voltage in order to change the field current and hence regulate the terminal voltage. Further, i've selected TL494 for this.
My difficulties:
1) I have to couple TL494 with a power mosfet. I've decided the switching frequency of TL 494 to be 20 KHz. The drain of mosfet would be connected to the voltage obtained by rectifying (half wave) the terminal voltage of that alternator. The source will be connected to one end of the field winding.
I require 5 A continuous current and in short duration, 6 A for 10 sec.
Kindly suggest a Power Mosfet which is easily available and cheap.
Also a proper optocoupler/pulse transformer for coupling.
2) the AVR circuitry will also be fed form the rectified terminal voltage. So i need to design a zener regulator .Kindly suggest a BJT so that the O/P of zener regulator is 15Volts, 25Watts max.(fig attatched)
I'll post the schematic soon..
PS: The AVR ahould be such that it can be used with alternators of different rating. (Max limit 5 KVA). Also, i need the cost to be low. Current AVRs available in India cost Rs. 2000 approx.
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