Help with basic electronics theory

Thread Starter

micktosin

Joined Mar 20, 2012
19
I have Dc-dc Boost converter designed to step up (12-24Volts) to 28.8Volts(10Amps). The converter is currently working perfectly(stepping up 24V-28.8voltage) with a dc power supply, however this Dc converter after completion, will be fed up to a max input power of 2400Watt(24V&100Amps) from a Dc generator. My question is, can the input power be pulsed width modulated from 2.4KW to 288Watt(28.8Volts &10Amps), by just reducing the duty cycle to the switching transistors? Because otherwise, i might be forced to buy a 2.4Kw rated load resistor, of which I'll rather not.

Second question; Is there a way i can locked the output to 28.8Volts regardless of the input Voltage(12-24Volts). Because currently i am using a 555 timer as my pwm, and just like other Chip they can't take high input feedback available from the output of the converter.
 

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kubeek

Joined Sep 20, 2005
5,776
I am not quite sure where you´re are loosing 2000W, but I think that using falstad simulator for anything more complex than a battery - LED - resistor circuit is a bad idea. Download LTspice and see what results you actually get.
Anyway the output current will mainly depend on what is the dutycycle of the switch control voltage.
 

Thread Starter

micktosin

Joined Mar 20, 2012
19
Hi there, (Please find attached diagram)
To rephrase my question.
I have Dc-dc Boost converter designed to step up (12-24Volts) to 28.8Volts(10Amps). The converter is currently working perfectly(stepping up 24V-28.8voltage) with a dc power supply, however this Dc converter after completion, will be fed up to a max input power of 2400Watt(24V&100Amps) from a Dc generator. My question is, can the input power be pulsed width modulated from 2.4KW to 288Watt(28.8Volts &10Amps), by just reducing the duty cycle to the switching transistors? Because otherwise, i might be forced to buy a 2.4Kw rated load resistor, of which I'll rather not.

Second question; Is there a way i can locked the output to 28.8Volts regardless of the input Voltage(12-24Volts). Because currently i am using a 555 timer as my pwm, and just like other Chip they can't take high input feedback available from the output of the converter.
 

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kubeek

Joined Sep 20, 2005
5,776
No, not in this configuration. Each of the mosfets will get 25% duty cycle regardless of the pwm frequency.
You would need to change the driving circuit to achieve any pwm modulation.
..And the counter is connected wrong.
 
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Thread Starter

micktosin

Joined Mar 20, 2012
19
I just searched for multiphase boost and came up with this, it covers the basics nicely and has a rather workable schematic included. http://cdn.intechopen.com/pdfs/1252...or_hybrid_fuel_cell_battery_power_sources.pdf
Massive thanks for that link, that was helpful. However, i am lost from section 6.1 -6.3 onwards(Implementation wise). Firstly, please can you suggest how to integrate the following into my circuit.

1. Simplified error amplifier section to get a constant output power
2. Analog control section to regulate the circuit output voltage.

Another question, hence i'm using a switch mode Dc converter, can a manipulation of the PWM duty cycle, reduce the output power to 288Watts from 2.4KW (Through averaging).
 
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