Voltage regulator for USB power supply

Hi everyone, I am trying to build a power supply from a set of resonator circuit. The circuit can provide 8W for a 43 ohms load at 19V. I want to charge my phone (5V, 1A, 5W) with it so I use a voltage regulator (LT1375). But when I connect it to my circuit, the voltage output become very low (50 mV). 

 

Any advice would be very helpful. Below is the resonator circuit to supply power (replace the source in voltage regulator circuit) and the voltage regulator circuit (replace the load in the resonator circuit).

Hi,

What is the output voltage of the voltage regulator? Did you get the 5V? I am a bit confused with your last statement about replacing the source of the resonator with the source of voltage regulator and likewise the load with the voltage regulator circuit. The LT1375 is usually used as a buck converter like the one attached. Well you see, you have a bridge rectifier in the circuit and there is no AC supply. I maybe just be wrong but there is something odd in the circuit.

Hi, Thank you for the reply. In my first diagram, there is a AC power in the left most circuit. So power is transferred through mutual inductance between a set of coils, then rectified to 19 V DC (8 W) when 43 ohm load is connected . But I want to use 5 V to charge my phone, so I use a buck converter LT1375 to extract 5 V. However, I only get 50 mV output in the simulation.

The LT1375 works fine by itself, but not with my DC supply after the rectifier. Basically I want to connect this AC-DC circuit in series with the DC-DC converter, but cannot get power as expected..

Hi , yuhao zhou

I think your ic might not be able to supply continuous current as per your requirement.
another reason may be defective battery. i suggest you to go for a simple circuit
which i have designed for you.pl see my attachment .

pl don t forget to review my rating.

V. Sambath kumar.

I had no problems running a simulation on your circuit to get the desired output specs of 5V and 1Amp, but the input voltage into the SMPS has to be high enough, the voltage output from the resonator circuit sags too much at the specs you indicated, too low for the SMPS to operate properly. Changing the input voltage source from 30 to 40 V on the resonator circuit was sufficient. It could be that you need to look at a different configuration on the SMPS, A SEPIC or a combined buck/boost will work above and below the output voltage.
Just out of curiosity, what's with the resonator system anyway, why such a complex way of generating the voltage input for the SMPS.
Cheers,
Richard

Further to my reply, couple of screen shots of the results with 40V drive.
Cheers,
Richard

Oops, wrong file, try again,
cheers,
Richard