Urgent! analysis of simply circuit diagram

[studystudystudy]

i attached a file. Need Pro in power electronic help me explain and analysis the circuit diagram.

this is my first design energy harvesting circuity. but teacher told me have some error, i spend a lot of time in searching the mistake i made. please help me to figure it out!



The voltage source is unstable can be ranging from 1 to 1000V
Input current is very small - about 25uA

1. C1 used to filter the DC voltage, but the value use is inappropriate. why? 1000uF with 10V

2. Zener diode connected series with diferrent polarity. used to regulated the voltage so that protect MemoryCap 5V? the Zener diode place in wrong way! why?

3. UF4007 is a ultra fast recovery rectifier. is it already rectifier? mean no need four UF4007 to make a rectifier?

These few question make me headache!!! your help deeply appreciated!! thank you thank you

 

[abhijithvp]

hi,

1st, i'm not a PE pro

2nd, i can't see your attachment..

though i can say these energy harvesting ckts require large enough 1mF capacitors..

don't know whats the need of connecting zener in series.. series with wot?

 

[studystudystudy]

the attachment or image, u can click on it, it will automative link to the image, so that u can see the full image. thanks

 

[Tahmid]

Hi,
Your capacitor is rated at 10v. At 500vac input, the output voltage will be 500*1.414 = 707v. It will blow away the capacitor. The arrangement of the zeners make them useless.
Here is the corrected version:

Firstly, you have to have the zener drop the voltage in something, ie the resistor as shown in the diagram. There is no need for back to back zeners since this is DC, not AC. Arrange as shown. The 10v cap has to placed after the voltage is stepped down, ie the zener has to clip the voltage so that the cap doesn't blow off. UF4007 is a rectifier that functions similarly to the 1N4007, just turns off quicker. 1N4007 in this application will also do.

Hope this helps.
Tahmid.