4v3 Zener & 680uH alternatives for Pickit 2 Clone

[sole_developer]

I'am trying to build a Pickit2 Clone available at: **broken link removed**

The problem is, I can't find a 4v3 Zener and a 680uH Inductor. Can I use a 100uH inductor instead of 680uH? Or should I build an Inductor (I don't think the design would accommodate it!). And can I substitute the 4v3 Zener with a 4v7 + resistor? Or should I use a LM385 (again, too lazy and I don't want to redesign the whole schematic here!)....

Thanks in advance guys!

 

[ahmad1954]

for inductor you can use six or seven 100uH inductor in series. about zener diode if power dissipation is not important, you can
use a resistor in series with diode in form that .4V should drop on resistor.

 

[FvM]

If you are lazy, use a 3.3V LDO.

 

[sole_developer]

Actually the original person has used the following diagram..I can't seem to figure out the resistor values if I use a 4v7 Zener.... I mean, is he caculating using (1/SQRT(1+RC)2)? How do I calculate the value of resistor required if using a 4v7 Zener...And which is a better for creating PCB Layouts from schematics, Proteus or Orcad? (which does a better job, placing components I mean, grouping all resistors, capacitors togethor, etc)....

Yes, I'am also considering using a 78LS33, but I'am gonna check if it is available first here!

Thanks in advance again!

 

[FvM]

4V7 zener diode would need an additional voltage divider, 4V3 gives still to high output voltage (about 3.6 V), how about using a 3V9 Z-diode? You can tune the output voltage with a small resistor in series with the diode (10 ohms range)

 

[sole_developer]

I'am currently using Proteus Simulator to simulate this.....and it doesn't seem to be working! The vout voltage just drops to 0...I can simulate this type of thing in Proteus right??

 

[FvM]

As far as I'm aware of, Proteus has no problems with basic analog circuits. So it's most likely some kind of simulation circuit or configuration error.

 

[sole_developer]

4V7 zener diode would need an additional voltage divider, 4V3 gives still to high output voltage (about 3.6 V), how about using a 3V9 Z-diode? You can tune the output voltage with a small resistor in series with the diode (10 ohms range)

How are you calculating the voltage, could you please let me know. And by the way, I found a 3v3 Zener.....How can I use the 3v3 Zener?

 

[shegzzyy]

I'am trying to build a Pickit2 Clone available at: **broken link removed**

The problem is, I can't find a 4v3 Zener and a 680uH Inductor. Can I use a 100uH inductor instead of 680uH? Or should I build an Inductor (I don't think the design would accommodate it!). And can I substitute the 4v3 Zener with a 4v7 + resistor? Or should I use a LM385 (again, too lazy and I don't want to redesign the whole schematic here!)....

Thanks in advance guys!

why not use 3v zenar in series with three in4148 diodes--3v+3(0.4v)=4.2v

 

[sole_developer]

why not use 3v zenar in series with three in4148 diodes--3v+3(0.4v)=4.2v

I need 3.3v at the output, but I can't figure out how the original guy is calculating the output voltage. Is he using the 1/SQRT(1+sq(wrc)) formula or what?? He has calculated based on the following diagram and using a 4v3 zener diode....I can't get a hold of 4v3, instead I have a 3v3 zener.......SO I just need to know how the output voltage is being calculated! Thanks again!

 

[FvM]

No idea how you arrived at the formula. Output voltage will be zener voltage - transistor base-emitter voltage, e.g. 0.6V.

 

[shegzzyy]

Re: 4v3 Zener & 680uH alternatives for Pickit 2 Clone

I think he arrived at vdd =4.3v-vbe-IeRe

- - - Updated - - -

I think he arrived at vdd =4.3v-vbe-IeRe

- - - Updated - - -

What of using a 3v and one in4148 in series?
3+0.4v=3.4v

 

[sole_developer]

Re: 4v3 Zener & 680uH alternatives for Pickit 2 Clone

I think he arrived at vdd =4.3v-vbe-IeRe

- - - Updated - - -

I think he arrived at vdd =4.3v-vbe-IeRe

- - - Updated - - -

What of using a 3v and one in4148 in series?
3+0.4v=3.4v

But according to the diagram, it doesn't make any sense.......Unless there is a voltage divide later on which he doesn't mention!

Actually I will just use a 4v7 in series with a resistor (to drop voltage by 0.4, I will try 10ohms)

 

[FvM]

Actually I will just use a 4v7 in series with a resistor (to drop voltage by 0.4, I will try 10ohms)

That's what makes no sense in my view.

A 3.3V zener with 1N4148 in series would be a good guess, however.

 

[sole_developer]

Ok...sorry guys for the late reply (was busy with some things...)...I'am going to design the circuit from scratch (bummer!)...anyways, I will let you know...and I will also post my modified circuit! Anyways, I trited simulating the thing on Proteus, but didn't work....so I have installed Orcad and will let you know how it goes.....

 

[sole_developer]

PS: Anyone here work with Orcad?? I can't seem to find the footprint of a 48pin Zif Socket......! Or is there a better alternate designing software package which has these components already...so that I can just pick and choose..?? Like I saw someone make a PCB as shown in the image....was this done using Eagle..???? Please advise.
Thanks!